ORCID Profile
0000-0001-5210-1282
Current Organisation
University of Tasmania
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Publisher: Hindawi Limited
Date: 23-12-2016
DOI: 10.1111/ANU.12274
Publisher: Cambridge University Press (CUP)
Date: 11-1998
DOI: 10.1017/S0025315400044519
Abstract: This study examined the relationships between food ration, intra- and interin idual variation in food consumption, observed behaviours and the growth of in idual juvenile greenback flounder ( Rhombosolea tapirina : Teleostei) held singly and in groups. Agonistic, feeding and neutral behavioural units were identified and described using video records and focal s ling. Agonistic behaviour, including nipping and pushing, were infrequent and accounted for % of behavioural units. The influence of food ration upon agonistic behaviour was investigated using three groups of six flounder offered either a low, medium or high food ration. The total number of agonistic behaviours recorded in each group did not differ significantly (P .05) suggesting food ration had little influence upon the total number of agonistic behaviours performed. Single flounder showed less intra- and less interin idual variation in day-to-day food consumption than in groups of six. Variation in food consumption increased with increasing food ration in single and in groups of flounder. Significant positive correlations between food consumption, intrain idual variation in food consumption and specific growth rate provided indirect evidence for the presence of feeding hierarchies. The small contribution made by agonistic behaviour to the total number of behaviours recorded for each group suggests exploitation competition, as opposed to interference competition, was the dominant competitive mechanism employed by juvenile greenback flounder.
Publisher: Authorea, Inc.
Date: 20-10-2020
Publisher: Elsevier BV
Date: 07-2206
Publisher: Elsevier BV
Date: 10-2004
Publisher: Springer Science and Business Media LLC
Date: 02-03-2021
Publisher: Wiley
Date: 02-08-2010
Publisher: Wiley
Date: 17-11-2022
DOI: 10.1111/JFD.13555
Abstract: Cardiac abnormalities may pose a threat to salmonid aquaculture due to their potential detrimental effect on fish health and welfare. The teleost heart is an extremely plastic organ with important morphological differences between wild and farmed fish that include ventricular shape, alignment of the bulbus arteriosus and epicardial fat deposition. However, little is known about how different factors and interactions among them may affect cardiac morphology of Atlantic salmon. To determine whether rearing temperature could induce cardiac malformations in large Tasmanian Atlantic salmon, we examined a range of cardiac morphology indicators and growth parameters in a population of 1–2 kg seawater salmon ( n = 60 temperature −1 diet −1 ) exposed to control and elevated temperatures of 15 and 19°C, respectively, while fed one of two commercial feeds with different dietary energy levels. Most fish possessed conspicuous fat around the heart with a tendency towards a rounded ventricle and a more obtuse angle of the bulbus arteriosus. However, fish showed no significant differences in heart shape and bulbus alignment in relation to water temperature and dietary energy. These results suggest that cardiac morphology of large Atlantic salmon is unlikely to be affected by rearing temperature and dietary energy during the grow‐out phase.
Publisher: Springer Science and Business Media LLC
Date: 29-05-2022
Publisher: University of Chicago Press
Date: 2013
DOI: 10.1086/667799
Abstract: Sourcing energy for reproduction is a major driver of the life-history characteristics of animals. Unlike other molluscs, cephalopods do not appear to have significant glycogen stores, and energy is either sourced directly from ingested food or mobilized from protein stores in the muscle. Given the importance of protein to cephalopods, this study quantified changes in protein turnover in the muscle tissue in reproductively immature and maturing/mature in iduals. Quantifying protein accretion and protein synthesis allowed an assessment of protein turnover in immature and maturing in iduals of the southern dumpling squid (Euprymna tasmanica), which has fast nonasymptotic growth, has a short generation time, and does not use lipid stores. This study found that protein turnover slowed in the mantle muscle tissue with gonad growth, suggesting an adaptive response to the energy demands associated with reproduction but one that allows for continued somatic growth and muscle function in these animals. However, the cost of reproduction may be indirect, with less energy available for somatic repair, and therefore may be responsible for the rapid senescence typical of many cephalopod species.
Publisher: Elsevier
Date: 2015
Publisher: Hindawi Limited
Date: 04-2004
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.FOODCHEM.2019.125140
Abstract: Pigment-depletion in the fillets of farmed Atlantic salmon (Salmo salar) arises after periods of elevated water temperatures with voluntary starving. This study tested the effects of dietary pre-loading with different pigment carotenoids (astaxanthin and/or canthaxanthin) combined with two α-tocopherol levels (normal and high: 500 and 1000 mg/kg, respectively) on pigment-depletion in vivo in Atlantic salmon after four weeks of challenge. We also tested whether oxidative stress manifested as an underlying depletion mechanism. Carotenoid levels in whole fillet homogenates were not decreased significantly post-challenge but fillet α-tocopherol concentrations were increased significantly in contrast to decreased oxidative stress indices. However, image analysis revealed localised fillet pigment-depletion following all dietary treatments. These data imply that localised pigment-depletion was not prevented by pre-loading of the fillet with different carotenoid-types/mixtures and increased of α-tocopherol levels from normal to high, respectively. Further, we suggest that oxidative stress might not facilitate pigment-depletion in vivo.
Publisher: Wiley
Date: 10-2004
Publisher: CABI
Date: 2010
Publisher: Elsevier BV
Date: 07-2020
Publisher: Elsevier BV
Date: 08-2022
DOI: 10.1016/J.COPBIO.2022.102734
Abstract: Aquaculture is critical for ensuring global food and nutrition security, and fed-aquaculture, which depends on formulated nutritionally balanced manufactured feeds, must be sustainable. Single-cell ingredients (SCI) are predicted to play a significant role in future aquafeeds and have the potential to underpin sustainable fed-aquaculture for many species. The value of an aquafeed ingredient includes nutritional, commercial, environmental, and socioeconomic factors. Here we aim to review approaches to understanding the value of ingredients and use this to outline a practical approach for considering the use of SCI in aquafeeds. We conclude that following an initial experimental focus on nutritional value, a collaborative and iterative approach with an aquafeed manufacturer will provide the most likely route to successful commercialisation of SCI.
Publisher: Public Library of Science (PLoS)
Date: 24-08-2016
Publisher: Elsevier BV
Date: 1992
Publisher: Springer Science and Business Media LLC
Date: 2000
Publisher: Authorea, Inc.
Date: 28-10-2020
Publisher: Hindawi Limited
Date: 03-2005
Publisher: Authorea, Inc.
Date: 04-11-2020
Publisher: Springer Science and Business Media LLC
Date: 03-07-2017
DOI: 10.1038/S41598-017-04806-2
Abstract: Understanding how aquatic species respond to extremes of DO and temperature is crucial for determining how they will be affected by climate change, which is predicted to increasingly expose them to levels beyond their optima. In this study we used novel animal-borne DO, temperature and depth sensors to determine the effect of extremes of DO and temperature on the vertical habitat use of Atlantic salmon Salmo salar in aquaculture cages. Salmon showed a preference for temperatures around 16.5 to 17.5 °C, however, selection of preferred temperatures was trumped by active avoidance of low DO ( % saturation) at the bottom of the cage. In addition to low DO, salmon also avoided warm surface waters ( .1 ° C), which led to a considerable contraction in the available vertical habitat. Despite their avoidance behavior, fish spent a large amount of time in waters with suboptimal DO ( % saturation). These results show that vertical habitat contraction could likely be a significant consequence of climate change if the reduction in DO outpaces the increase in hypoxia tolerance through local adaptation. They furthermore highlight that site-specific environmental conditions and stock-specific tolerance thresholds may need to be considered when determining stocking densities.
Publisher: Elsevier BV
Date: 12-2005
Publisher: Elsevier BV
Date: 06-2009
Publisher: Springer Science and Business Media LLC
Date: 1999
Publisher: Hindawi Limited
Date: 02-2005
Publisher: Hindawi Limited
Date: 06-1995
Publisher: American Chemical Society (ACS)
Date: 08-07-2011
DOI: 10.1021/JF201871W
Abstract: The limited activity of Δ6 fatty acid desaturase (FAD6) on α-linolenic (ALA, 18:3n-3) and linoleic (LA, 18:2n-6) acids in marine fish alters the long-chain (≥C(20)) polyunsaturated fatty acid (LC-PUFA) concentration in fish muscle and liver when vegetable oils replace fish oil (FO) in aquafeeds. Echium oil (EO), rich in stearidonic acid (SDA, 18:4n-3) and γ-linoleic acid (GLA, 18:3n-6), may enhance the biosynthesis of n-3 and n-6 LC-PUFA by bypassing the rate-limiting FAD6 step. Nutritional and environmental modulation of the mechanisms in LC-PUFA biosynthesis was examined in barramundi, Lates calcarifer , a tropical euryhaline fish. Juveniles were maintained in either freshwater or seawater and fed different dietary LC-PUFA precursors present in EO or rapeseed oil (RO) and compared with FO. After 8 weeks, growth of fish fed EO was slower compared to the FO and RO treatments. Irrespective of salinity, expression of the FAD6 and elongase was up-regulated in fish fed EO and RO diets, but did not lead to significant accumulation of LC-PUFA in the neutral lipid of fish tissues as occurred in the FO treatment. However, significant concentrations of eicosapentaenoic acid (EPA, 20:5n-3) and arachidonic acid (ARA, 20:4n-6), but not docosahexaenoic acid (DHA, 22:6n-3), appeared in liver and, to a lesser extent, in muscle of fish fed EO with marked increases in the phospholipid fraction. Fish in the EO treatment had higher EPA and ARA in their liver phospholipids than fish fed FO. Endogenous conversion of dietary precursors into neutral lipid LC-PUFA appears to be limited by factors other than the initial rate-limiting step. In contrast, phospholipid LC-PUFA had higher biosynthesis, or selective retention, in barramundi fed EO rather than RO.
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.CBD.2017.02.005
Abstract: There is currently renewed interest in farming triploid Atlantic salmon. Improving farming requires identifying triploid specific phenotypic and physiological traits that are uniquely derived from ploidy per se and developed under optimal growing conditions. This study investigated firstly, the impact of ploidy on growth performance and whole body composition of Atlantic salmon at different early freshwater stages [34dph (days post-hatching) alevin, 109dph fry, and 162dph parr] and secondly, whether phenotypic differences at these stages were reflected in protein s les collected from whole fish, white muscle or liver tissue. Female diploid and triploid Atlantic salmon (n=3) were first fed at 35dph and then maintained by feeding to satiation on commercial feeds. Triploids were significantly lower in weight at the late alevin and fry stages but matched diploid weight at the parr stage. The whole-body lipid content was significantly higher for triploids at the parr stage, while the whole-body lipid class profile was broadly similar and was largely not affected by ploidy. Comparative label-free shotgun proteomic analysis did not detect significant alterations in protein expression between diploids and triploids at any growth stage. The present results indicate that ploidy under optimal growing conditions and during early freshwater stages only result in small phenotypic differences in weight and whole body lipid content that were not reflected at the proteome level. These findings suggest that optimal husbandry conditions for freshwater Atlantic salmon are similar between ploidies, at least for all-female populations.
Publisher: Elsevier BV
Date: 06-2009
Publisher: Elsevier BV
Date: 06-2004
Publisher: Springer Science and Business Media LLC
Date: 03-06-2021
DOI: 10.1038/S41598-021-91304-1
Abstract: This is the first study in an aquatic ectotherm to combine a stoichiometric bioenergetic approach with an endpoint stochastic model to explore dietary macronutrient content. The combination of measuring respiratory gas (O 2 and CO 2 ) exchange, nitrogenous (ammonia and urea) excretion, specific dynamic action (SDA), metabolic energy substrate use, and whole-body protein synthesis in spiny lobster, Sagmariasus verreauxi , was examined in relation to dietary protein. Three isoenergetic feeds were formulated with varying crude protein: 40%, 50% and 60%, corresponding to CP 40 , CP 50 and CP 60 treatments, respectively. Total CO 2 and ammonia excretion, SDA magnitude and coefficient, and protein synthesis in the CP 60 treatment were higher compared to the CP 40 treatment. These differences demonstrate dietary protein influences post-prandial energy metabolism. Metabolic use of each major energy substrate varied at different post-prandial times, indicating suitable amounts of high-quality protein with major non-protein energy-yielding nutrients, lipid and carbohydrate, are critical for lobsters. The average contribution of protein oxidation was lowest in the CP 50 treatment, suggesting mechanisms underlying the most efficient retention of dietary protein and suitable dietary inclusion. This study advances understanding of how deficient and surplus dietary protein affects energy metabolism and provides approaches for fine-scale feed evaluation to support sustainable aquaculture.
Publisher: Elsevier BV
Date: 2019
Publisher: University of Chicago Press
Date: 11-2010
DOI: 10.1086/656387
Abstract: This study is the first to examine the underlying process of growth in a cephalopod, the southern dumpling squid (Euprymna tasmanica), to ascertain the mechanism by which indeterminate growth is achieved in this live-fast, die-young group of animals. This is the first study to estimate rates of protein synthesis and growth of squid from 7 to 140 d of age, providing an understanding of both the pattern and the process of growth throughout the lifetime of a squid species. Younger and smaller in iduals had greater rates of protein synthesis and protein synthesis retention efficiency, as well as more RNA, than did older and larger in iduals. Variation in growth rates among older, larger in iduals was a function of in iduals with faster growth rates having greater protein synthesis retention efficiency and also greater concentrations of protein. Critically, growth did not cease in the adults and, with an average of 10% of protein synthesized being retained, the mechanism to support the nonasymptotic growth model of cephalopods is provided.
Publisher: Cambridge University Press (CUP)
Date: 14-03-2012
DOI: 10.1017/S0007114512000426
Abstract: The present study aimed to measure tissue protein synthesis in sea bream fed isonitrogenous diets that contained 63, 55 and 50 % fishmeal in the latter two diets, 16 and 27 % of the fishmeal protein was replaced with plant protein. Over a 35 d period, there were no differences in feed intake, growth or feed efficiency among the three diets. Protein metabolism was then measured in the liver and white muscle tissue as rates of protein synthesis and as the capacity for protein synthesis before feeding (0 h) and at different times after feeding (4–48 h). Diet did not have a significant effect on protein synthesis or on the capacity for protein synthesis in either tissue. The capacity for protein synthesis was not affected by time after feeding, and overall mean values were 81·02 ( se 1·68) and 4·07 ( se 0·94) mg RNA/g protein for the liver and white muscle, respectively. Liver and white muscle fractional rates of protein synthesis were significantly higher at 4–8 h, intermediate at 12 h and were not different among pre-feeding (0 h), 24 and 48 h. Overall, the indices of protein metabolism measured at various times over 48 h following feeding were closely aligned with measurements of feeding, growth and growth efficiency established over a longer time scale.
Publisher: Elsevier BV
Date: 03-2022
DOI: 10.1016/J.CBPA.2021.111121
Abstract: Apparent digestibility and gastrointestinal evacuation rate were measured to assess the potential of five commercially available protein sources for their inclusion in feeds for juvenile slipper lobster, Thenus australiensis. Protein sources tested were fishmeal, krill meal, lupin meal, soybean meal and squid by-product meal. Apparent digestibility of crude protein ranged from 79.6% to 95.3%, with fishmeal protein significantly less digestible than lupin meal, squid by-product meal and soybean meal. Gastrointestinal evacuation rate was estimated from marker replacement, where yttrium oxide replaced ytterbium oxide. Faeces were collected every 3 h for 48 h, and a kinetic model was used to calculate the rate and time for the second marker to replace the first marker. Gastrointestinal evacuation (≥ 95%) was completed between 4 and 6 h with no significant differences among protein sources. Faeces consisted of both markers in equal parts 2.7 to 5.0 h after the feed switch, with lupin meal reaching the midpoint significantly faster than squid by-product meal and reference feed. The present study is the first in crustaceans to examine the relationship between apparent digestibility and gastrointestinal evacuation, showing more digestible protein sources had slower evacuation rates. The combined approach provides deeper insight into crustaceans' digestive physiology and helps understand their ability to digest specific ingredients. Further research is recommended to understand protein requirements in a broader context to verify highly digestible protein sources meet all nutritional requirements.
Publisher: Public Library of Science (PLoS)
Date: 21-07-2016
Publisher: Elsevier BV
Date: 12-2007
Publisher: Elsevier
Date: 2022
Publisher: Wiley
Date: 13-01-2016
DOI: 10.1111/JFD.12438
Abstract: Triploid Atlantic salmon tend to develop a higher prevalence of skeletal anomalies. This tendency may be exacerbated by an inadequate rearing temperature. Early juvenile all-female diploid and triploid Atlantic salmon were screened for skeletal anomalies in consecutive experiments to include two size ranges: the first tested the effect of ploidy (0.2-8 g) and the second the effect of ploidy, temperature (14 °C and 18 °C) and their interaction (8-60 g). The first experiment showed that ploidy had no effect on skeletal anomaly prevalence. A high prevalence of opercular shortening was observed (average prevalence in both ploidies 85.8%) and short lower jaws were common (highest prevalence observed 11.3%). In the second experiment, ploidy, but not temperature, affected the prevalence of short lower jaw (diploids > triploids) and lower jaw deformity (triploids > diploids, highest prevalence observed 11.1% triploids and 2.7% diploids) with a trend indicating a possible developmental link between the two jaw anomalies in triploids. A radiological assessment (n = 240 in iduals) showed that at both temperatures triploids had a significantly (P < 0.05) lower number of vertebrae and higher prevalence of deformed in iduals. These findings (second experiment) suggest ploidy was more influential than temperature in this study.
Publisher: Elsevier BV
Date: 2021
Publisher: Wiley
Date: 12-1991
Publisher: Elsevier BV
Date: 02-2007
DOI: 10.1016/J.CBPB.2006.10.099
Abstract: The worldwide increase in aquaculture production and the concurrent decrease of wild fish stocks has made the replacement of fish oil in aquafeeds an industry priority. Oil from a plant source Echium plantagineum L., Boraginaceae, has high levels of stearidonic acid (SDA, 18:4omega3, 14%) a biosynthetic precursor of omega-3 long-chain (> or =C(20)) polyunsaturated fatty acids (omega3 LC-PUFA). Atlantic salmon (Salmo salar L.) parr were fed a control fish oil diet (FO) or one of 3 experimental diets with 100% canola oil (CO) 100% SDA oil (SO), and a 1:1 mix of CO and SDA oil (MX) for 42 days. There were no differences in the growth or feed efficiency between the four diets. However, there were significant differences in the fatty acid (FA) profiles of the red and white muscle tissues. Significantly higher amounts of SDA, eicosapentaenoic acid (20:5omega3, EPA), docosahexaenoic acid (22:6omega3, DHA) and total omega3 FA occurred in both red and white muscle tissues of fish fed SO and FO compared with those fed CO. Feeding SO diet resulted in omega3 LC-PUFA amounts in the white and red muscle being comparable to the FO diet. This study shows that absolute concentration (mug/g) of EPA, DHA and total omega3 have been maintained over 6 weeks for Atlantic salmon fed 14% SDA oil. The balance between increased biosynthesis and retention of omega3 LC-PUFA to maintain the concentrations observed in the SO fed fish remains to be conclusively determined, and further studies are needed to ascertain this.
Publisher: Wiley
Date: 06-2002
Publisher: Springer Science and Business Media LLC
Date: 09-2023
Publisher: Springer Science and Business Media LLC
Date: 17-02-2011
Publisher: Walter de Gruyter GmbH
Date: 18-10-2014
DOI: 10.2478/S11535-013-0134-0
Abstract: This review aimed to place crustacean research on in vivo protein synthesis into a broader context, assess its potential for providing further insights into crustacean nutrition and physiology, and recommend future directions relevant to crustacean aquaculture. In crustaceans the flooding dose measurement of protein synthesis is the only method that has been used, it is relatively complex, time consuming and uses radioactive labels. Protein synthesis provides a subtle approach to assessing imbalances and deficiencies in dietary amino acid and energy. In addition, the calculation of protein synthesis retention efficiency (SRE) is recommended in order to understand and optimize parameters such as feeding regime and diet composition. For prawns, SRE was highest at optimum dietary protein content and quality. Similarly the most efficient feeding regimes in juvenile lobsters were demonstrated by the highest efficiency of retaining synthesized protein. Understanding how various abiotic and biotic factors influence protein synthesis has great potential for improving different aspects of crustacean aquaculture but very few studies have done this better knowledge of how abiotic and biotic factors affect crustacean protein synthesis will contribute to optimising growth of crustaceans in culture.
Publisher: Springer Science and Business Media LLC
Date: 1999
Publisher: Public Library of Science (PLoS)
Date: 17-05-2018
Publisher: Elsevier BV
Date: 08-2011
Publisher: Hindawi Limited
Date: 12-2001
Publisher: Elsevier BV
Date: 11-2010
Publisher: Elsevier BV
Date: 07-2003
Publisher: Wiley
Date: 08-2006
Publisher: Wiley
Date: 26-12-2020
DOI: 10.1111/RAQ.12522
Abstract: The respiratory quotient (RQ) has been used extensively as an index to evaluate metabolic energy expenditure in terrestrial animals including humans. In contrast, RQ use in understanding physiology and nutrition of aquatic ectotherms has been restricted due to technical challenges in measuring total CO 2 in water. With technical advances in measuring total CO 2 in water, RQ in aquatic ectotherms can be accurately determined and is potentially available as a valuable method. Here, we provide a comprehensive review of studies on RQ and metabolic energy substrate use in aquatic ectotherms. Metabolic energy substrate use is evaluated by a reliable stoichiometric bioenergetic approach, based on measuring RQ and nitrogen quotient (NQ) simultaneously. Stoichiometry provides a non‐destructive and unequivocal way to quantify the instantaneous oxidation of each major energy substrate (protein, lipid or carbohydrate). This review aims to refine knowledge about bioenergetics of aquatic ectotherms under different conditions including nutritional aspects of sustainable aquaculture. Notably, stoichiometry provides a promising approach to optimize feeds and feeding regimes to realize sustainable aquaculture under differing conditions and with differing feed ingredients. It also provides an approach to consider climate change impacts and physiological adaptation mechanisms for survival and development in farmed environments and natural ecosystems. Stoichiometric bioenergetics knowledge in aquatic ectotherms has relevance to commercial impacts in the face of overfishing and food security, and ecological significance in the face of environmental change scenarios. We suggest expanding the use of stoichiometry in future bioenergetic research in emerging aquaculture species.
Publisher: Informa UK Limited
Date: 03-04-2021
Publisher: MDPI AG
Date: 15-08-2023
Abstract: Fish aquaculture is a rapidly expanding global industry, set to support growing demands for sources of marine protein. Enhancing feed efficiency (FE) in farmed fish is required to reduce production costs and improve sector sustainability. Recognising that organisms are complex systems whose emerging phenotypes are the product of multiple interacting molecular processes, systems-based approaches are expected to deliver new biological insights into FE and growth performance. Here, we establish 14 erse layers of multi-omics and clinical covariates to assess their capacities to predict FE and associated performance traits in a fish model (Oncorhynchus tshawytscha) and uncover the influential variables. Inter-omic relatedness between the different layers revealed several significant concordances, particularly between datasets originating from similar material/tissue and between blood indicators and some of the proteomic (liver), metabolomic (liver), and microbiomic layers. Single- and multi-layer random forest (RF) regression models showed that integration of all data layers provide greater FE prediction power than any single-layer model alone. Although FE was among the most challenging of the traits we attempted to predict, the mean accuracy of 40 different FE models in terms of root-mean square errors normalized to percentage was 30.4%, supporting RF as a feature selection tool and approach for complex trait prediction. Major contributions to the integrated FE models were derived from layers of proteomic and metabolomic data, with substantial influence also provided by the lipid composition layer. A correlation matrix of the top 27 variables in the models highlighted FE trait-associations with faecal bacteria (Serratia spp.), palmitic and nervonic acid moieties in whole body lipids, levels of free glycerol in muscle, and N-acetylglutamic acid content in liver. In summary, we identified subsets of molecular characteristics for the assessment of commercially relevant performance-based metrics in farmed Chinook salmon.
Publisher: Canadian Science Publishing
Date: 22-10-2019
DOI: 10.1139/Z93-055
Abstract: The aim of this study was to investigate the influences of diet, ration, and in idual variation on protein-nitrogen flux in the grass carp, Ctenopharyngodon idella (Valenciennes). Grass carp were fed either lettuce or a pelleted diet or were starved. Fish fed lettuce had lower rates of protein accretion than those fed the pelleted diet and some lost body protein. Rates of whole-animal protein synthesis were ranked as follows: pellet-fed fish lettuce-fed fish starved fish. Productive protein value was negatively correlated with rate of protein degradation and positively correlated with the efficiency of retention of synthesized protein. Rates of protein synthesis were not correlated with productive protein value and these data suggest that ultimately it is the rate at which proteins are degraded that determines efficiency of growth. Comparison of pairs offish eating the same diet and amounts of food but having different growth rates demonstrated that the faster growing fish had lower rates of protein degradation, higher retention of synthesized protein, higher RNA activity, a lower capacity for synthesis, and variable rates of protein synthesis.
Publisher: Wageningen Academic Publishers
Date: 2010
Publisher: Elsevier BV
Date: 10-2001
Publisher: Wiley
Date: 08-1992
Publisher: Elsevier BV
Date: 05-2008
DOI: 10.1016/J.YGCEN.2008.03.013
Abstract: Cytochrome P450 aromatase (CYP19) is a key enzyme in the steroidogenic pathway that catalyses the conversion of testosterone to estrogen, and therefore is thought to influence gonadal sex differentiation. In an effort to understand the role of this enzyme in ovarian differentiation, we isolated cDNA encoding the two distinct isoforms, ovarian and brain (termed cyp19a and cyp19b, respectively) of adult common carp, Cyprinus carpio. The cloned cDNA for cyp19a had an open reading frame (ORF) of 518 amino acid residues, in contrast to cyp19b with an ORF of 511 amino acids. Sequence and phylogenetic analysis showed that these CYP19 isoforms were orthologous with previously described cyp19a and cyp19b from other teleosts. Quantitative real-time PCR indicated that both isoforms are expressed in adult ovary and brain, with predominant expression of cyp19a in the ovary and cyp19b in the brain. The major aromatase expressing tissue was found to be the brain, with greatest cyp19b expression in the anterior quarter (telencephalon) in both sexes. The gonad showed sexually dimorphic expression of both genes and dimorphic expression of cyp19a was observed in the cerebellum and the liver. Ontogenic expression showed that only the ovarian aromatase transcript is inherited maternally, with lower expression observed through early larval development under warmer rearing conditions. The differential and overlapping expression suggests these two aromatase genes have different roles in reproductive physiology.
Publisher: Elsevier BV
Date: 2023
Publisher: Wiley
Date: 03-1996
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 11-2007
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.FOODCHEM.2013.04.052
Abstract: Pathogen infection stimulates the fatty acid (FA) metabolism and the production of pro-inflammatory derivatives of FA. Barramundi, Lates calcarifer, was fed on a diet rich in preformed long-chain (⩾C20) polyunsaturated fatty acids (LC-PUFA) from fish oil (FO), to compare with diets containing high levels of C18 precursors for LC-PUFA - stearidonic (SDA) and γ-linolenic acid (GLA) - from Echium plantagineum (EO), or rapeseed oil (RO) rich in α-linolenic acid (ALA), but a poor source of LC-PUFA and their precursors. After 6weeks, when growth rates were similar amongst the dietary treatments, a sub-lethal dose of Streptococcus iniae was administered to half of the fish, while the other half were maintained unchallenged and were pair-fed with the infected fish. Under a disease challenge situation, the tissue FA depots depleted at 3days post-infection (DPI) and were then restored to their previous concentrations at 7DPI. During the infection period, EO fish had a higher content of n3 and n6 PUFA in their tissues, higher n3:n6 PUFA ratio and reduced levels of the eicosanoids, TXB2 and 6-keto-PGF1α, in their plasma compared with RO fish. Fish fed on FO and EO had a longer lasting and enduring response in their FA and eicosanoid concentrations, following a week of bacterial infection, compared with those fed on RO. EO, containing SDA and GLA and with a comparatively higher n3:n6 PUFA ratio, proved more effective than RO in compensating for immunity stress.
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 07-2002
Publisher: Cambridge University Press (CUP)
Date: 08-02-2011
DOI: 10.1017/S0007114510005714
Abstract: Vegetable oils (VO) have become the predominant substitute for fish oil (FO) in aquafeeds however, the resultant lower content of n -3 long-chain ( ≥ C20) PUFA ( n -3 LC-PUFA) in fish has put their use under scrutiny. The need to investigate new oil sources exists. The present study tested the hypothesis that in Atlantic salmon ( Salmo salar L.), a high intake of stearidonic acid (SDA) from Echium oil (EO) would result in increased n -3 LC-PUFA biosynthesis due to a lower requirement for Δ6 desaturase. Comparisons were made with fish fed on diets containing rapeseed oil (RO) and FO in freshwater for 112 d followed by 96 d in seawater. EO fish had higher whole-carcass SDA and eicosatetraenoic acid (ETA) in freshwater and prolonged feeding on the EO diet in seawater resulted in higher SDA, ETA, EPA and docosapentaenoic acid (DPA) compared with RO fish. Fatty acid mass balance of freshwater fish indicated higher biosynthesis of ETA and EPA in EO fish compared with fish fed on the other diets and a twofold increase in n -3 LC-PUFA synthesis compared with RO fish. In seawater, n -3 biosynthetic activity was low, with higher biosynthesis of ETA in EO fish and appearance of all desaturated and elongated products along the n -3 pathway. SDA-enriched VO are more suitable substitutes than conventional VO from a human consumer perspective due to the resulting higher SDA content, higher total n -3 and improved n -3: n -6 ratio obtained in fish, although both VO were not as effective as FO in maintaining EPA and DHA content in Atlantic salmon.
Publisher: Elsevier BV
Date: 03-2022
Publisher: Elsevier BV
Date: 12-2011
Publisher: Hindawi Limited
Date: 31-03-2021
DOI: 10.1111/ARE.15219
Publisher: Wiley
Date: 08-1998
Publisher: Elsevier BV
Date: 03-2003
Publisher: Wiley
Date: 10-1992
Publisher: Wiley
Date: 23-06-2016
Abstract: Understanding diet- and environmentally induced physiological changes in fish larvae is a major goal for the aquaculture industry. Proteomic analysis of whole fish larvae comprising multiple tissues offers considerable potential but is challenging due to the very large dynamic range of protein abundance. To extend the coverage of the larval phase of the Atlantic salmon (Salmo salar) proteome, we applied a two-step sequential extraction (SE) method, based on differential protein solubility, using a nondenaturing buffer containing 150 mM NaCl followed by a denaturing buffer containing 7 M urea and 2 M thiourea. Extracts prepared using SE and one-step direct extraction were characterized via label-free shotgun proteomics using nanoLC-MS/MS (LTQ-Orbitrap). SE partitioned the proteins into two fractions of approximately equal amounts, but with very distinct protein composition, leading to identification of ∼40% more proteins than direct extraction. This fractionation strategy enabled the most detailed characterization of the salmon larval proteome to date and provides a platform for greater understanding of physiological changes in whole fish larvae. The MS data are available via the ProteomeXchange Consortium PRIDE partner repository, dataset PXD003366.
Publisher: Elsevier BV
Date: 06-2009
DOI: 10.1016/J.CBPA.2009.02.015
Abstract: Rates of protein synthesis were measured in the whole body and tissues of southern dumpling squid Euprymna tasmanica to validate the use of a flooding-dose of (3)H phenylalanine for the measurement of protein synthesis with different size squid and to make a preliminary investigation into the effects of feeding regime. In smaller (2.8+/-0.5 g, mean+/-SE) and larger (14.8+/-2.2 g) squid whole body fractional rates of protein synthesis were 9.45+/-1.21 and 1.49+/-0.29% d(-1), respectively. Differences in total whole body protein content meant there was no difference in absolute rates of whole body protein synthesis between the larger and smaller squid. In larger squid, fractional rates of protein synthesis were significantly higher in the digestive gland (9.24+/-1.63% d(-1)) than in the arm tissue (1.43+/-0.31% d(-1)), which were significantly higher than in the anterior (0.56+/-0.13% d(-1)) and posterior (0.36+/-0.04% d(-1)) mantle. In smaller squid there were no differences in protein synthesis between tissues and high in idual variation, due to differences in feeding, was a likely cause. Consequently, the effect of feeding regime on protein synthesis was compared between two groups of in idually held squid: daily-feeding and minimal-feeding squid. The daily-feeding squid had significantly higher feed intake, gained mass and had a significantly higher growth rate than the minimal-feeding squid which lost mass. Whole body protein synthesis was significantly higher in the daily-feeding squid as was the protein content of the digestive gland, anterior and posterior mantle. There were few other differences in indices of protein metabolism. In idual squid showed differences in growth and protein metabolism, and there were significant relationships between growth rate and both rates of protein synthesis and protein degradation. Thus, higher in idual growth was a consequence of increased protein synthesis, decreased protein degradation and, therefore, increased efficiency of retaining synthesised protein.
Publisher: Springer Science and Business Media LLC
Date: 12-02-2018
Publisher: Canadian Science Publishing
Date: 04-1994
DOI: 10.1139/Z94-083
Abstract: To test whether triploid Atlantic salmon (Salmo salar L.) parr were at a disadvantage compared with diploid parr the growth and feeding behaviour of in idual parr in separate and mixed groups of diploid and triploid fish were studied in two experiments. At the end of the first experiment (separate groups) the diploid parr had significantly higher mean specific growth rates than the triploid parr. This was due to significantly higher growth during the first 40 days of the experiment growth was not significantly different over the last 52 days. The consumption rates of in idual parr were measured using radiography. There were no consistent differences in consumption rates between triploid and diploid parr in mixed or separate groups. However, at the start of the experiment the mean consumption rates of the triploid parr were significantly lower than those of the diploid parr and could explain their lower growth rates. There were no differences in the amount of damage to the caudal fin between triploid and diploid parr in either experiment. However, in a mixed group, damage to the dorsal fin of triploid parr was more severe than to the dorsal fin of diploid parr, which suggested that triploid parr in mixed groups were more likely to be the recipients of agonistic actions than the diploid parr. However, the specific growth rates of the diploid and triploid parr in mixed groups were not significantly different. It was concluded that under certain circumstances. triploid and diploid Atlantic salmon parr may exhibit differences in growth and feeding behaviour.
Publisher: Pensoft Publishers
Date: 25-11-2014
Publisher: Elsevier BV
Date: 07-2010
Publisher: Elsevier BV
Date: 05-2020
Publisher: CABI
Date: 2010
Publisher: Elsevier BV
Date: 05-2006
Publisher: Elsevier
Date: 1995
Publisher: Inter-Research Science Center
Date: 10-03-2022
DOI: 10.3354/MEPS13984
Abstract: Species redistributions are one of the most prevalent changes observed in oceans worldwide due to climate change. One of the major challenges is being able to predict temperature-driven changes to species interactions and the outcome of these changes for marine communities due to the complex nature of indirect effects. In the ocean-warming hotspot of south-east Australia, the ranges of many species have shifted poleward. The range of the eastern rock lobster Sagmariasus verreauxi has extended into warming Tasmanian waters inhabited by the resident southern rock lobster Jasus edwardsii , which may lead to increased competitive interactions between the species. Using video monitoring, we investigated how the 2 species compete for food at current (18°C), future (21°C) and future heatwave (24°C) summer temperatures. Behavioural competition occurred in 80% of experiments, during which J. edwardsii won 84% of competitive interactions and showed more aggressive behaviour at all temperatures. This indicates that resident J. edwardsii is not only more dominant in direct food competition than the range-shifting S. verreauxi but, surprisingly, also sustains competitive dominance beyond its physiological thermal optimum under predicted future ocean warming and heatwave scenarios.
Publisher: Elsevier BV
Date: 06-2012
Publisher: Informa UK Limited
Date: 04-10-2021
Publisher: Wiley
Date: 06-2005
DOI: 10.1111/J.1365-2761.2005.00636.X
Abstract: Previous studies have demonstrated that beta-glucans stimulate Atlantic salmon, Salmo salar L., head kidney macrophages both in vitro and in vivo and increase protection against various pathogens. Based on our previous work that showed potent immunostimulatory CpG motif-containing oligodeoxynucleotides increased resistance to amoebic gill disease (AGD), the present study investigated the immunostimulatory effects of three commercial beta-glucan-containing feeds and their ability to increase resistance to AGD. All three commercial beta-glucans were able to stimulate the respiratory burst activity of Atlantic salmon head kidney macrophages in vitro, albeit at different times and concentrations. However, dietary incorporation of the beta-glucans was unable to stimulate the in vivo respiratory burst activity of head kidney macrophages, or serum lysozyme production, and did not increase resistance against AGD. However, this trial showed for the first time that a small subpopulation of Atlantic salmon subjected to a severe AGD infection was able to resist becoming heavily infected and furthermore survive the challenge.
Publisher: Elsevier BV
Date: 08-2004
Publisher: Elsevier BV
Date: 02-2011
Publisher: Inter-Research Science Center
Date: 31-10-2007
DOI: 10.3354/DAO01855
Abstract: In this study, experiments were conducted to examine the effect of an acute necrotic bacterial gill infection on the metabolic rate (M(O2)) of Atlantic salmon Salmo salar. Fed and unfed Atlantic salmon smolts were exposed to a high concentration (5 x 10(12) CFU ml(-1)) of the bacteria Tenacibaculum maritimum, their routine and maximum metabolic rates (M(O2rout) and M(O2max), respectively) were measured, and relative metabolic scope determined. A significant decrease in metabolic scope was found for both fed and unfed infected groups. Fed infected fish had a mean +/- standard error of the mean (SEM) decrease of 2.21 +/- 0.97 microM O2 g(-1) h(-1), whilst unfed fish a mean +/- SEM decrease of 3.16 +/- 1.29 microM O2 g(-1) h(-1). The decrease in metabolic scope was a result of significantly increased M(O2rout) of both fed and unfed infected salmon. Fed infected fish had a mean +/- SEM increase in M(O2rout) of 1.86 +/- 0.66 microM O2 g(-1) h(-1), whilst unfed infected fish had a mean +/- SEM increase of 2.16 +/- 0.72 microM O2 g(-1) h(-1). Interestingly, all groups maintained M(O2max) regardless of infection status. Increases in M(O2rout) corresponded to a significant increase in blood plasma osmolality. A decrease in metabolic scope has implications for how in iduals allocate energy fish with smaller metabolic scope will have less energy to allocate to functions such as growth, reproduction and immune response, which may adversely affect the efficiency of fish growth.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Cambridge University Press (CUP)
Date: 04-1995
DOI: 10.1079/BJN19950061
Abstract: The aim of the present study was to compare the nutritive value of bacterial single-cell protein (BSCP) with that of fishmeal in rainbow trout ( Oncorhynchus mykiss (Walbaum)). Four diets were formulated to contain a total of 458 g crude protein/kg of which 0% was from BSCP in diet 1 (BSCP-0), 25% in diet 2 (BSCP-25), 62·5% in diet 3 (BSCP-62·5) and 100% in diet 4 (BSCP-100) the remainder of the protein was from fishmeal. There were two studies: in study 1, duplicate groups of twenty-five fish were fed on one of the four experimental diets at the rate of 20 g/kg body weight per d for 132 d. Feed consumption rates of in idual fish were measured using radiography and the overall apparent absorption efficiency for N in each group was measured over a 2-week period. In study 2, N intake, consumption, absorption and accretion were measured for each fish under controlled environmental conditions (12 h:12 h light-dark regime 14°). Higher dietary levels of BSCP resulted in significantly higher feed consumption rates but reduced N absorption efficiency and growth rates. However, a diet containing 25% BSCP (75% fishmeal) did not significantly influence growth rates, feed consumption and absorption efficiency compared with a 100% fishmeal diet. The N growth efficiencies were highest in fish fed on the diet containing the highest level of fishmeal and significantly decreased with increasing BSCP content. Construction of N budgets demonstrated that the reduction in growth in fish eating an increasingly larger proportion of BSCP was due to a decrease in N absorption and an increase in the excretion of urea.
Publisher: Elsevier BV
Date: 12-2014
Publisher: Elsevier BV
Date: 11-2008
Abstract: Atlantic salmon (Salmo salar L.) can produce (n-3) long-chain (LC)-PUFA when fed biosynthetic precursors. This has potential for developing sustainable aquafeeds. Echium oil (EO) is rich in stearidonic acid [SDA 18:4(n-3)] and bypasses the initial Delta6 desaturase (FAD6) step in the (n-3) LC-PUFA biosynthetic pathway. EO was fed to seawater Atlantic salmon for 12 wk and compared with fish fed a diet containing canola oil (CO), a source of alpha-linolenic acid [ALA 18:3(n-3)] or fish oil (FO) that provides (n-3) LC-PUFA. Fatty acid (FA) composition of liver, white muscle, and whole fish was measured to show whether dietary precursors were endogenously biosynthesized to LC-PUFA. Gene expression of liver FA elongase and FAD5 was upregulated in EO fish compared with FO fish. Furthermore, dietary precursors affected the FA concentrations of direct biosynthetic products in all tissues. The increased gene expression in the EO fish was reflected by an increased FA concentration of eicosapentaenoic acid [20:5(n-3)] in the liver compared with the CO fish. However, the high concentrations of (n-3) LC-PUFA found in seawater Atlantic salmon fed diets rich in FO were not attained via biosynthesis from precursors (ALA or SDA) in diets.
Publisher: Springer Science and Business Media LLC
Date: 16-06-2015
DOI: 10.1038/NCOMMS8365
Abstract: The growing human population must be fed, but historic land-based systems struggle to meet expanding demand. Marine production supports some of the world’s poorest people but increasingly provides for the needs of the affluent, either directly by fishing or via fodder-based feeds for marine and terrestrial farming. Here we show the expanding footprint of humans to utilize global ocean productivity to feed themselves. Our results illustrate how incrementally each year, marine foods are sourced farther from where they are consumed and moreover, require an increasing proportion of the ocean’s primary productivity that underpins all marine life. Though mariculture supports increased consumption of seafood, it continues to require feeds based on fully exploited wild stocks. Here we examine the ocean’s ability to meet our future demands to 2100 and find that even with mariculture supplementing near-static wild catches our growing needs are unlikely to be met without significant changes.
Publisher: Elsevier BV
Date: 06-2022
Publisher: Springer Science and Business Media LLC
Date: 12-1993
DOI: 10.1007/BF00004415
Publisher: Elsevier BV
Date: 10-2007
DOI: 10.1016/J.CBPA.2007.05.018
Abstract: Replacing fish oil with that from a docosahexaenoic acid (22:6omega3, DHA) rich single cell micro-organism, thraustochytrid Schizochytrium sp. L, in diets for Atlantic salmon (Salmo salar) was investigated. Four experimental diets containing 100% thraustochytrid oil (TO), 100% palm oil (PO) and a 4:1 palm and thraustochytrid oil mixture (MX) were compared to a fish oil (FO) diet over 9 weeks. A saltwater transfer challenge occurred at the end of the trial for 14 days to test the diet treatments on the ability of salmon to smolt. There were no significant differences in the feed consumption of the diets or the digestibility of the omega3 or omega6 PUFA, indicating no differences in the digestibility of fatty acids between diets. No significant differences were noted between the growth of fish on the four diet treatments. Significant differences were noted in the fatty acid profiles of the fish muscle tissues between all diets. Fish on the TO diet had a significantly greater percentage of DHA in muscle tissue compared with fish on all other diets. Blood osmolarity, which is inversely related to the ability of salmon to smolt, from the TO and FO fed fish was significantly lower than that of fish on the PO diet. This study showed that thraustochytrid oil can be used to replace fish oil in Atlantic salmon diets without detriment to the growth of parr. Including thraustochytrid oil in fish diets significantly increases the amount of DHA in Atlantic salmon muscle and therefore is a candidate for use in oil blends for salmon diets. Thraustochytrid oil provides a renewable source of essential fatty acids, in particular DHA, for aquafeeds.
Publisher: Wiley
Date: 09-2006
DOI: 10.1007/S11745-006-5042-5
Abstract: Regiospecific and traditional analysis, of both storage and membrane lipids, was performed on gill, white muscle, and red muscle s les taken from Atlantic salmon (Salmo salar) to gauge the effect of elevated water temperature. The fish, fed a commercial diet, were held at an elevated water temperature of 19 degrees C. Total n-3 PUFA, total PUFA, and n-3/n-6 and unsaturated/saturated fatty acid (UFA/SFA) ratios in the FA profile of the total lipid extract in the white muscle were fairly low compared with fish grown at 15 degrees C. Adaptation of structural and storage lipids at elevated temperatures was shown by a significant (P < 0.01) reduction in PUFA especially in the percentage of EPA (6-8%). Further adaptation was indicated by the percentages of SFA, which were significantly (P< 0.05) higher in gill (56%) and white muscle (58%) polar lipid fractions and coincided with lower percentages of n-3, n-6, and total PUFA. The regiospecific profiles indicated a high affinity of DHA to the sn-2 position in both the TAG (61-68%) and polar lipid (35-60%) fractions. The combination of detailed regiospecific and lipid analyses demonstrated adaptation of cell membrane structure in Atlantic salmon grown at an elevated water temperature.
Publisher: Springer Science and Business Media LLC
Date: 10-2003
DOI: 10.1007/S10126-002-0096-8
Abstract: The replacement of fish oil with a dried product made from thraustochytrid culture, a marine microorganism, in canola-oil-based diets for Atlantic salmon was investigated. Salmon (37 g) were fed for 51 days on diets containing only canola oil, canola oil and fish oil, or canola oil and the thraustochytrid. There were no significant differences in final weight (106.1 +/- 1.1 g), weight gain (69.6 +/- 1.1 g), feed consumption (16.5 +/- 0.2 mg dry matter g(-1) d(-1)), feed efficiency ratio (1.15 +/- 0.03 g (g-1)), or productive protein value (51.2% +/- 1.7%) between the diets. Nor were there any significant differences in whole-body chemical composition, organ somatic indices, or measures of immune function. However, following transfer to seawater and 2 challenges with Vibrio anguillarum, cumulative mortality was significantly lower in fish fed some fish oil than in those fed the 2 diets containing no fish oil. In conclusion, the thraustochytrid had no detrimental effects on the performance of salmon but, at the current inclusion of 10%, failed to confer the same effect as fish oil under challenging conditions.
Publisher: Hindawi Limited
Date: 09-1999
Publisher: Wiley
Date: 04-05-2016
DOI: 10.1111/JFD.12492
Abstract: Triploid Atlantic salmon populations are associated with higher prevalence of lower jaw skeletal anomalies affecting fish performance, welfare and value deleteriously. Anomalous lower jaw can be curved downward (LJD), shortened (SJ) or misaligned (MA). Two separate groups of triploid Atlantic salmon (~12 g) with either normal lower jaw (NOR) or SJ were visually assessed four times over three months for presence and concurrence of jaw anomalies (with severity classified) and opercular shortening to understand the relatedness of these anomalous developmental processes. The prevalence of jaw anomalies increased in both groups over time (NOR group - SJ, LJD and MA combined 0-24.5% SJ group - LJD and MA combined 17-31%). SJ and LJD occurred both independently and concurrently whereas MA exclusively concurred with them. All three anomalies could be concurrent. Severity of both LJD and SJ increased in the SJ group only. Opercular shortening recovery was observed in both groups but at a slower rate in the SJ group. The SJ group specific growth rate (SGR) was significantly (P < 0.05) lower than the NOR group. This study demonstrated the concurrence of SJ, LJD and MA and showed possible deleterious consequences deriving from the conditions.
Publisher: Cambridge University Press (CUP)
Date: 05-1996
DOI: 10.1017/S0025315400030708
Abstract: The aims of the present study were to investigate food consumption, growth and the dynamics of feeding hierarchies in the same groups of juvenile greenback flounder ( Rhombosolea tapirina: Teleostei) fed either high or low rations. Differential food consumption by in idual greenback flounder held in groups of 20 showed the presence of feeding hierarchies in which in iduals consumed between 0 and 22% of the available food. Inter-in idual differences in food consumption resulted in different growth rates leading to growth depensation (measured as an increase in the coefficient of variation for weight). Intra-in idual differences in food consumption tended to be larger for flounder which consumed a lower share of the available food. When the group ration was reduced the inter-in idual and intra-in idual variations in food consumption increased. Consequently, the relationship between inter-in idual and intra-in idual variation in food consumption tended to become stronger at lower food availability and indicated an increase in the strength of the feeding hierarchies. This study suggests that in idual differences in food consumption, mediated through exploitation competition, contribute to growth depensation in this species of flatfish.
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/MF03149
Abstract: The aim of the present study was to determine how the lifetime growth rates of adult southern calamary Sepioteuthis australis related to somatic and reproductive condition. A hierarchy of biological levels was explored: whole-animal, muscle fibre, and proximal condition. Evidence at all biological levels suggested that allocation of energy given to growth and reproduction was gender-specific. Females may not be allocating the same level of energy to somatic growth due to a greater requirement to re-allocate energy for reproductive growth. There was evidence that faster-growing males were in better somatic and reproductive condition. However, both males and females in better somatic condition were also in better reproductive condition. Fast growth rates by in iduals were achieved primarily by muscle fibre growth, rather than production of new fibres. However, mantle muscle instantaneous growth rates (assessed through RNA : protein ratio) decreased as males became larger and more reproductively mature no association was evident in females. An inverse correlation between gonad size and muscle instantaneous growth rates in females suggested energy was being directed away from somatic growth and towards reproductive growth. There was evidence that lifetime growth rates could predict the reproductive or somatic condition of adult calamary, but this was gender-specific.
Publisher: Elsevier BV
Date: 06-2022
DOI: 10.1016/J.CBD.2022.100994
Abstract: Understanding the molecular mechanisms that underlie differences in feed efficiency (FE) is an important step toward optimising growth and achieving sustainable salmonid aquaculture. In this study, the liver and white muscle proteomes of feed efficient (EFF) and inefficient (INEFF) Chinook salmon (Oncorhynchus tshawytscha) reared in seawater were investigated by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In total, 2746 liver and 702 white muscle proteins were quantified and compared between 21 EFF and 22 INEFF fish. GSEA showed that gene sets related to protein synthesis were enriched in the liver and white muscle of the EFF group, while conversely, pathways related to protein degradation (amino acid catabolism and proteolysis, respectively) were the most affected processes in the liver and white muscle of INEFF fish. Estimates of in idual daily feed intake and share of the meal within tank were significantly higher in the INEFF than the EFF fish showing INEFF fish were likely more dominant during feeding and overfed. Overeating by the INEFF fish was associated with an increase in protein catabolism. This study found that fish with different FE values had expression differences in the gene sets related to protein turnover, and this result supports the hypothesis that protein metabolism plays a role in FE.
Publisher: Wiley
Date: 12-1999
Publisher: Elsevier BV
Date: 11-2022
Publisher: Elsevier BV
Date: 12-2012
Publisher: American Chemical Society (ACS)
Date: 23-12-2011
DOI: 10.1021/JF203633Z
Abstract: Reducing the lipid content in fish prior to feeding a fish oil finishing diet (FOFD) has the potential to improve n-3 long-chain (≥ C(20)) polyunsaturated fatty acid (LC-PUFA) restoration. This study had two main objectives: (1) determine whether feeding Atlantic salmon smolt a 75% palm fatty acid distillate diet (75PFAD) improves the apparent digestibility (AD) of saturated fatty acids (SFA) and (2) examine whether a food deprivation period after growth on 75PFAD leads to higher n-3 LC-PUFA restoration in the fillet when applying a FOFD. The AD of SFA was higher for 75PFAD compared to that of a fish oil (FO) diet. The relative level (as % total fatty acids (FA)) of n-3 LC-PUFA was higher in unfed fish compared to that in continuously fed fish after 21 and 28 day FOFD periods, respectively. Our results suggest that a food deprivation period prior to feeding a FOFD improves the efficiency of n-3 LC-PUFA restoration in the fillet of Atlantic salmon smolt.
Publisher: Elsevier BV
Date: 05-2000
Publisher: Wiley
Date: 12-04-2008
DOI: 10.1007/S11745-008-3175-4
Abstract: Phytosterols occur in high concentration in canola (Brassica napus L.) and other vegetable oils such as from the borage plant Echium (Echium plantagineum L.). We investigated if Atlantic salmon (Salmo salar) digest and accumulate dietary phytosterols in significant amounts in muscle and liver. Phytosterols are lipid soluble, lower cholesterol and reduce the risk of coronary heart disease in humans. We aimed to determine if fatty fish, such as salmon, can be used as a delivery source of this functional food component. Three diets containing canola oil (CO), Echium oil (EO) and fish oil (FO) were fed to Atlantic salmon smolt over 9 weeks. The digestibility of natural abundances of phytosterols by Atlantic salmon was poor compared to cholesterol. However, phytosterols accumulated in liver and muscle of fish. Significantly increased concentrations of 24-methylenecholesterol, c esterol, beta-sitosterol and total phytosterol occurred in livers of EO fed fish compared to FO fed fish. C esterol concentrations increased in CO fed fish compared to the FO fed fish. We demonstrated that natural abundances of dietary phytosterols are digested by and accumulated in liver and white muscle of Atlantic salmon smolt. However, phytosterol levels in salmon muscle will not be a major source of phytosterols in human diets and would not be expected to significantly effect human cardiovascular health.
Publisher: Inter-Research Science Center
Date: 15-08-2019
DOI: 10.3354/MEPS13054
Publisher: Elsevier BV
Date: 02-1998
Publisher: Elsevier BV
Date: 1992
Publisher: Elsevier BV
Date: 03-2001
Publisher: Hindawi Limited
Date: 12-1995
Publisher: Cambridge University Press (CUP)
Date: 04-2006
DOI: 10.1079/ASC200528
Abstract: This study investigated the effects of 100 g/kg increments of crude protein (approx. 250 (P25) to 550 (P55) g/kg of crude protein) in paired iso-energetic diets on the growth performance of the juvenile Australian short-finned eel (1·83 (s.e. 0·01) g average wet weight). The highest growth response was obtained with treatment P45 followed by P35, P55 and P25. It appeared that food efficiency ratio (FER) increased with increasing crude protein content in low energy diets (treatments P25 and P35). However, 100 g/kg increase in dietary crude protein content (from 450 to 550 kg crude protein per kg diet) in high energy diets resulted in lower FER for treatment P55 than for the treatment P45. The protein efficiency ratio (PER, %) was higher in low protein:low energy diets (treatments P25 and P35) than that of high protein:high energy diets (treatments P45 and P55). The protein productive values (PPV, %) for treatments followed a similar trend to PER in this experiment. The lowest PPV was obtained by the treatment P55 and it was significantly different from that of the other three treatments. A proportional increase in dietary crude protein content in paired iso-energetic diets did not significantly change the whole body protein content. However, a small increase in whole body protein content with increasing dietary crude protein in each group was detected. In conclusion, the present study showed protein sparing effects of lipids and carbohydrates in the diets of the short-finned eel. Further studies specifically investigating the effects of dietary carbohydrate to lipid ratios at different protein levels would improve diet formulation and reduce nutrient impact in intensive recirculation systems.
Publisher: Wiley
Date: 08-1998
Publisher: Wiley
Date: 06-1992
Publisher: Springer International Publishing
Date: 2019
Publisher: Elsevier BV
Date: 06-2013
DOI: 10.1016/J.CBPA.2013.03.019
Abstract: Metabolic responses to sub-optimal temperature deplete lipid depots, remodel membrane lipid and alter the fatty acid profile in the whole body and tissues of ectothermic vertebrates including fish. The magnitude of these changes may depend on dietary history including oil sources with different fatty acid compositions. Barramundi, Lates calcarifer (Perciformes, Latidae), a tropical ectothermic fish, was fed on diets either rich in dietary long-chain (≥C(20)) polyunsaturated fatty acids (LC-PUFA) from fish oil, rich in stearidonic and γ-linolenic acid (SDA and GLA, respectively) from Echium plantagineum, or rapeseed oil deficient in LC-PUFA. Following 5 weeks at the optimum temperature of 30 °C when growth rates were comparable amongst dietary treatments, water temperature was dropped to 20 °C for 1 week for half of the animals and maintained at 30 °C for the other half. Decreased temperature increased the liver and skeletal muscle content of LC-PUFA in fish fed on echium oil compared with rapeseed oil, while dietary LC-PUFA depots in fish oil fed-fish depleted rapidly in the week of sub-optimal temperature. The lipid unsaturation index of cellular membrane in the liver and muscle increased under low temperature at the same rate regardless of dietary oil. Therefore, rapid exposure of an ectothermic vertebrate to a lower and sub-optimal temperature caused significant modulation in fatty acid composition. We propose that the tolerance of barramundi, a representative of tropical farmed fish, to sub-optimal temperature will be enhanced when fatty acid substrates closer to the LC-PUFA are available in their diet.
Publisher: Elsevier BV
Date: 11-2009
Publisher: Public Library of Science (PLoS)
Date: 15-12-2016
Publisher: Elsevier BV
Date: 02-2011
Publisher: Elsevier BV
Date: 10-2000
Publisher: Hindawi Limited
Date: 12-2001
Publisher: MDPI AG
Date: 30-08-2022
DOI: 10.3390/ANI12172241
Abstract: Spiny lobsters have a range of complex chemical communication pathways that contribute to feeding behaviour. Feed intake is modulated by feed availability and feed characteristics, such as attractiveness and palatability, with behavioural factors, such as social competition and circadian rhythm, providing an extra layer of complexity. In this study, we investigated the effect of feed frequency on survival and growth of early-stage (instar 2–6) juvenile Palunirus ornatus. In addition, we investigated the interactive effect of feed frequency and circadian rhythm on lobster feed response. Lobsters were fed a set ration at a frequency of either one, two, four, eight, sixteen or thirty-two times per day over 49 days. The effect of feed frequency on growth and survival was determined. Circadian feeding activity under these feeding treatments was assessed by time-lapse photography. Increased feed frequency from one to sixteen feeds daily improved growth by increasing apparent feed intake (AFI) and feed attraction, as confirmed by the increased presence of lobsters in the feeding area. The rapid leaching of feed attractant, particularly free amino acid, suggests a beneficial effect of multiple feeding frequencies on feed intake and growth. However, more than sixteen feeds per day resulted in decreased feed intake and a subsequent reduction in growth. The decrease in feed intake is thought to be associated with saturation of the culture environment with attractants, resulting in a reduced behavioural response to feed supplies. This may indicate the need for depletion of attractants to retrigger a feeding response. As lobsters were grown communally, faster growth at sixteen rations per day was also coupled with increased cannibalism, likely driven by increased vulnerability with the occurrence of more frequent ecdysis events. Whereas circadian rhythm indicated more activity at night, an interaction between daytime activity and feed frequency was not observed.
Publisher: Elsevier BV
Date: 07-2007
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.FOODCHEM.2013.02.032
Abstract: Feeding fish a fish oil finishing diet (FOFD) after grow-out on vegetable oil diet is one strategy to restore eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels. We investigated restoration of EPA and DHA in rainbow trout fed a FOFD preceded by a grow-out period on 50% or 75% palm fatty acid distillate (PFAD) diets at optimal (15°C) or elevated (20°C) water temperatures. Using the FOFD restored EPA and DHA in fillet and whole carcass of fish previously fed either 50% PFAD diet from 85% to 98% or 75% PFAD from 66% to 93% of values obtained for fish fed FO diet throughout. Water temperature did not influence EPA and DHA restoration. Growing rainbow trout with diets where FO was replaced by either 50% or 75% PFAD followed by a FOFD reduced FO usage by around 30% and 44% at 15°C, respectively, and 32% and 48% at 20°C, respectively.
Publisher: Elsevier BV
Date: 07-1991
Publisher: Elsevier BV
Date: 05-2008
DOI: 10.1016/J.CBPA.2008.02.023
Abstract: Early stage phyllosoma larvae of the spiny rock lobster Jasus edwardsii were examined for swimming speed, feeding, oxygen consumption and nitrogen excretion as instantaneous performance indicators when exposed to different irradiance levels. Swimming speed was measured in recently hatched Stage I larvae while all other parameters were measured in larvae from hatch to mid-Stage V. The swimming speed of recently hatched Stage I phyllosoma increased logarithmically between light intensities of 2.9 x 10(14) and 1.8 x 10(16) quanta s(-1) cm(-2) indicating that, within this range, swimming activity was only suppressed at the lowest irradiance level. Larvae examined under dark (no light) conditions showed lower feed intake, oxygen consumption and nitrogen excretion than larvae under low (7.7 x 10(12) q s(-1) cm(-2)) and high (3.9 x 10(14) q s(-1) cm(-2)) light intensities, and this was a consistent pattern observed throughout development from hatch to Stage V. There was no difference in feeding, oxygen consumption and nitrogen excretion between larvae exposed to low and high light intensities. However, from mid-Stage I to mid-Stage V, the metabolic feeding efficiency (feed intake:oxygen consumption ratio) was consistently higher in larvae exposed to low light intensity than in phyllosoma assessed in the dark and under high irradiance. A light intensity of about 7.7 x 10(12) quanta s(-1) cm(-2) and no higher than 3.9 x 10(14) quanta s(-1) cm(-2) is recommended to stimulate feeding and optimise metabolic feeding efficiency in early larval stages of J. edwardsii.
Publisher: Elsevier BV
Date: 08-2003
DOI: 10.1016/S1096-4959(03)00143-X
Abstract: Dietary sunflower oil (SFO) was used to gradually replace fish oil (FO) in six diets (which also contained fish meal) for Atlantic salmon parr (initial mass: 21.7 g). The effect on growth performance, tissue fatty acid profiles and disease resistance was monitored after 63 days. At the conclusion of the trial, no significant differences were detected in growth between any of the feeds. Fatty acid composition of whole carcass, dorsal muscle and liver generally reflected that of the diets. Forty percent of the FO could be replaced by SFO before tissue 22:6n-3 was significantly reduced, although other essential and non-essential fatty acids were more susceptible to change. Significant differences were detected in cumulative mortality of Atlantic salmon challenged with Vibrio anguillarum at the trials conclusion, although this was not correlated to the inclusion level of SFO. Despite the changes observed to the tissue fatty acid profile, there was no significant effect on growth suggesting that SFO is a suitable alternative to FO in diets for Atlantic salmon parr when fish meal is also included.
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 04-2003
Publisher: Elsevier BV
Date: 04-2003
Publisher: Elsevier BV
Date: 11-2001
DOI: 10.1016/S1095-6433(01)00409-3
Abstract: This study aimed to measure protein synthesis and growth performance in flatfish, Rhombosolea tapirina, fed on three feeding regimes: 1% body wt. fed in the morning (MM1) 2% body wt. fed in the morning (MM2) and 2% body wt. fed in equal amounts in the morning and in the afternoon (MA2). After 6 weeks there were no significant differences in wet wt., protein growth or efficiency of protein-nitrogen flux. Significantly lower protein consumption on MM1 resulted in significantly lower rates of protein synthesis and degradation compared with MM2 but not MA2. After 18 weeks there were still no significant differences between feeding regimes although trends in growth and efficiency reflected the situation after 6 weeks. Fish were maintained in idually, and when analysed on this basis, there were significant relationships between protein consumption and protein synthesis [k(s)=0.92, k(r)+1.16 (n=17 r(2)=0.49 P<0.005)], between protein consumption and protein degradation [k(d)=0.82, k(r)+1.06 (n=17 r(2)=0.41 P<0.005)] and between average daily protein consumption and protein growth [k(g)=0.15, k(rx)-0.15 (n=17 r(2)=0.75 P<0.001)]. Thus, increasing protein consumption resulted in increased protein synthesis and growth. However, the combination of high rates of protein synthesis and protein degradation in relation to protein consumption, and resulting high anabolic stimulation and low retention of synthesised protein, contributed to the low growth performance of greenback flounder.
Publisher: Hindawi Limited
Date: 09-2007
Publisher: Elsevier BV
Date: 10-2012
DOI: 10.1016/J.FOODCHEM.2012.04.004
Abstract: Sesamin, a major sesame seed lignan, has erse biological functions including the modulation of molecular actions in lipid metabolic pathways and reducing cholesterol levels. Vertebrates have different capacities to biosynthesize long-chain PUFA from dietary precursors and sesamin can enhance the biosynthesis of ALA to EPA and DHA in marine teleost. Early juvenile barramundi, Lates calcarifer, were fed for two weeks on diets rich in ALA or SDA derived from linseed or Echium plantagineum, respectively. Both diets contained phytosterols and less cholesterol compared with a standard fish oil-based diet. The growth rates were reduced in the animals receiving sesamin regardless of the dietary oil. However, the relative levels of n-3 LC-PUFA in total lipid, but not the phospholipid, increased in the whole body by up to 25% in animals fed on sesamin with ALA or SDA. Sesamin reduced the relative levels of triacylglycerols and increased polar lipid, and did not affect the relative composition of phospholipid subclasses or sterols. Sesamin is a potent modulator for LC-PUFA biosynthesis in animals, but probably will have more effective impact at advanced ages. By modulating certain lipid metabolic pathways, sesamin has probably disrupted the body growth and development of organs and tissues in early juvenile barramundi.
Publisher: Springer Science and Business Media LLC
Date: 10-07-2011
Publisher: Springer Science and Business Media LLC
Date: 04-1995
DOI: 10.1007/BF00002458
Publisher: MDPI AG
Date: 25-06-2021
DOI: 10.3390/ANI11071889
Abstract: Following a meal, a series of physiological changes occurs in fish as they digest, absorb and assimilate ingested nutrients. This study aims to assess post-prandial free amino acid (FAA) activity in gilthead sea bream consuming a partial marine protein (fishmeal) replacement. Sea bream were fed diets where 16 and 27% of the fishmeal protein was replaced by plant protein. The essential amino acid (EAA) composition of the white muscle, liver and gut of sea bream was strongly correlated with the EAA composition of the 16% protein replacement diet compared to the 27% protein replacement diet. The mean FAA concentration in the white muscle and liver changed at 4 to 8 h after a meal and was not different to pre-feeding (0 h) and at 24 h after feeding. It was confirmed in this study that 16% replacement of marine protein with plant protein meets the amino acid needs of sea bream. Overall, the present study contributes towards understanding post-prandial amino acid profiles during uptake, tissue assimilation and immediate metabolic processing of amino acids in sea bream consuming a partial marine protein replacement. This study suggests the need to further investigate the magnitude of the post-prandial tissue-specific amino acid activity in relation to species-specific abilities to regulate metabolism due to dietary nutrient utilization.
Publisher: Elsevier BV
Date: 2003
Publisher: Elsevier BV
Date: 12-2011
Publisher: Wiley
Date: 2000
Publisher: CRC Press
Date: 19-07-2011
Publisher: Elsevier BV
Date: 06-2019
Publisher: The Royal Society
Date: 22-07-2026
Publisher: Frontiers Media SA
Date: 07-02-2020
DOI: 10.3389/FMICB.2023.1065823
Abstract: Gut microbiota play important roles in fish health and growth performance and the microbiome in fish has been shown to be a biomarker for stress. In this study, we surveyed the change of Chinook salmon ( Oncorhynchus tshawytscha ) gut and water microbiota in freshwater recirculating aquaculture systems (RAS) for 7 months and evaluated how gut microbial communities were influenced by fish health and growth performance. The gut microbial ersity significantly increased in parallel with the growth of the fish. The dominant gut microbiota shifted from a predominance of Firmicutes to Proteobacteria, while Proteobacteria constantly dominated the water microbiota. Photobacterium sp. was persistently the major gut microbial community member during the whole experiment and was identified as the core gut microbiota for freshwater farmed Chinook salmon. No significant variation in gut microbial ersity and composition was observed among fish with different growth performance. At the end of the trial, 36 out of 78 fish had fluid in their swim bladders. These fish had gut microbiomes containing elevated proportions of Enterococcus, Stenotrophomonas , Aeromonas, and Raoultella . Our study supports the growing body of knowledge about the beneficial microbiota associated with modern salmon aquaculture systems and provides additional information on possible links between dysbiosis and gut microbiota for Chinook salmon.
Publisher: Springer Science and Business Media LLC
Date: 04-12-2020
DOI: 10.1038/S41598-020-78052-4
Abstract: In an ocean warming hotspot off south-east Australia, many species have expanded their ranges polewards, including the eastern rock lobster, Sagmariasus verreauxi . This species is likely extending its range via larval advection into Tasmanian coastal waters, which are occupied by the more commercially important southern rock lobster, Jasus edwardsii . Here, thermal tolerances of these lobster species at two life stages were investigated to assess how they may respond to warming ocean temperatures. We found that the pattern, optimum and magnitude of thermal responses differed between performance measures, life stages and species. Sagmariasus verreauxi had a warmer optimal temperature for aerobic scope and escape speed than J. edwardsii . However, J. edwardsii had a higher magnitude of escape speed, indicating higher capacity for escape performance. There were also differences between life stages within species, with the larval stage having higher variation in optimal temperatures between measures than juveniles. This inconsistency in performance optima and magnitude indicates that single performance measures at single life stages are unlikely to accurately predict whole animal performance in terms of life-time survival and fitness. However, combined results of this study suggest that with continued ocean warming, S. verreauxi is likely to continue to extend its distribution polewards and increase in abundance in Tasmania.
Publisher: Hindawi Limited
Date: 12-2001
Publisher: Cambridge University Press (CUP)
Date: 12-2002
DOI: 10.1017/S1357729800053170
Abstract: Fish meal is the most widely used protein source in commercial eel foods and information on the nutritive value of more economical protein sources is needed in order to improve cost-effectiveness of diets. This investigation was conducted to determine apparent digestibility coefficients of available plant and animal meals for juvenile Australian short-finned eel (Anguilla australis australis, Richardson). The suitability of a modified Guelph-type settlement faecal collector in eel digestibility studies was assessed. Animal by-product (spray-dried meat solubles blood meal high fat poultry meal) and plant protein (soya bean canola maize gluten lupin field pea) meals were mixed with a reference diet and marker (0·3: 0·69: 0·01) and the resultant test diets given to the juvenile eels (3·15 (s.e. 0·42) g) at 0·05 live weight per day. The reference diet and all the test diets were well accepted by the fish. Apparent digestibility coefficients for crude protein (ADC CP ) for maize gluten meal (MGM), lupin meal (LM) and blood meal (BM) were found to be 0·97, 0·96 and 0·96 respectively and they were significantly (P 0·001) higher than that for the other ingredients. However, apparent digestibilities for dry matter (ADC DM ) and energy (ADC kJ ) were significantly (P 0·0001) higher for animal by-products than for plant proteins except for maize gluten meal. This was explained by the higher content of nitrogen free extractives in the former plant proteins. There was a strong positive correlation between ADC DM and ADC kJ for all ingredients (P 0·01). Weaker positive correlations were also found between ADC CP and ADC DM and between ADC CP and ADC kJ . Similar results obtained for warm water species using similar faecal collection techniques and over limited eel digestibility data support the suitability of the modified Guelph-type settlement collector system in digestibility studies with juvenile eels.
Publisher: Cambridge University Press (CUP)
Date: 04-2001
DOI: 10.1017/S1357729800058100
Abstract: Many studies with fin fish have demonstrated the potential to use alternative dietary protein sources to fish meal based on growth responses, although these trials mostly neglect to determine if such protein sources affect immune function. This study investigated the effect of fish meal replacement with dehulled lupin meal (LPN) or hydrolysed poultry feather meal (FTH). Atlantic salmon ( Salmo salar L.) parr were supplied isonitrogenous and isoenergetic diets with 40% of the dietary protein provided by LPN or FTH, or 400 g/kg of the dietary protein provided equally by LPN and FTH (MIX). A diet mainly containing fish-meal protein acted as a control (CON). Growth, immune function, blood chemistry and disease resistance were assessed after 56 days. Significant differences ( P 0·05) in weight gain were detected between Atlantic salmon given the CON and FTH diets, whilst those salmon given LPN and MIX did not differ from any other. Productive protein values were significantly lower ( P 0·01) for salmon on FTH compared with those on CON and MIX. Immune function (as assessed by lysozyme, antiprotease, neutrophil oxygen radical production and plasma total immunoglobulin) and blood chemistry (as assessed by plasma total protein and glucose) were not significantly ( P 0·05) affected by any diet. Mortality rates of Atlantic salmon challenged with Vibrio anguillarum were not influenced by diet. These data suggest Atlantic salmon could be supplied diets with the fish meal component reduced to supply approximately 600 g/kg of the total protein, with the remaining 400 g/kg supplied by dehulled lupin meal or a combined dehulled lupin and hydrolysed poultry feather meal without any adverse effects on growth, immune function or blood chemistry.
Publisher: Informa UK Limited
Date: 07-2001
Publisher: Springer Science and Business Media LLC
Date: 20-04-2012
Publisher: Elsevier BV
Date: 08-2012
Publisher: Springer Science and Business Media LLC
Date: 17-05-2019
DOI: 10.1007/S00360-019-01221-Z
Abstract: Metabolism in aquatic ectotherms evaluated by oxygen consumption rates reflects energetic costs including those associated with protein synthesis. Metabolism is influenced by nutritional status governed by feeding, nutrient intake and quality, and time without food. However, little is understood about contribution of protein synthesis to crustacean energy metabolism. This study is the first using a protein synthesis inhibitor cycloheximide to research contribution of cycloheximide-sensitive protein synthesis to decapod crustacean metabolism. Juvenile Sagmariasus verreauxi were subject to five treatments: 2-day fasted lobsters sham injected with saline 2-day fasted lobsters injected with cycloheximide 10-day starved lobsters injected with cycloheximide post-prandial lobsters fed with squid Nototodarus sloanii with no further treatment and post-prandial lobsters injected with cycloheximide. Standard and routine metabolic rates in starved lobsters were reduced by 32% and 41%, respectively, compared to fasted lobsters, demonstrating metabolic downregulation with starvation. Oxygen consumption rates of fasted and starved lobsters following cycloheximide injection were reduced by 29% and 13%, respectively, demonstrating protein synthesis represents only a minor component of energy metabolism in unfed lobsters. Oxygen consumption rate of fed lobsters was reduced by 96% following cycloheximide injection, demonstrating protein synthesis in decapods contributes a major proportion of specific dynamic action (SDA). SDA in decapods is predominantly a post-absorptive process likely related to somatic growth. This work extends previously limited knowledge on contribution of protein synthesis to crustacean metabolism, which is crucial to explore the relationship between nutritional status and diet quality and how this will affect growth potential in aquaculture species.
Publisher: Elsevier BV
Date: 04-2009
DOI: 10.1016/J.CBPA.2008.12.017
Abstract: Protein synthesis is an essential growth process in all animals. Little information is available on post-prandial protein synthesis and even less where different protein sources are compared. Protein synthesis was measured at 4 and 24 h after feeding juvenile barramundi in order to determine the effect of using lupin as a partial protein replacement for fish meal on the post-prandial protein metabolism. Juvenile barramundi (4.3+/-0.6 g) were held in a recirculation system (27 degrees C, salinity 10 per thousand and 24 h light) for 15 days. Fish were fed one of two isonitrogenous isoenergetic diets (40% crude protein, 16% lipid and 18.5 GE MJ kg(-1)). One diet was formulated with 100% fish meal as the protein source while the other had 45% of the protein replaced with lupin ingredients (lupin kernel meal (Lupinus angustifolius) and lupin protein concentrate). All fish were fed a ration of 6%.d(-1) and feed intake was not significantly different between the two diets. Specific growth rate (SGR) and growth efficiency (in relation to protein (PPV) and energy (PEV)) were 6.5+/-0.14%.d(-1), 43.8+/-2.72% and 38.31+/-1.56%, respectively, and were not significantly different between the two diets. There was no significant difference in protein synthesis between the two diets at 4 and 24 h after feeding, however protein synthesis was significantly higher 4 h after feeding than at 24 h (p=0.02). Neither growth performance nor protein metabolism was altered by replacing 45% of the protein with lupin protein and indicated this to be a suitable protein source for barramundi feeds.
Publisher: Wiley
Date: 26-08-2019
DOI: 10.1111/RAQ.12287
Publisher: Elsevier BV
Date: 10-2021
Publisher: EDP Sciences
Date: 07-1992
DOI: 10.1051/ALR:1992022
Publisher: Elsevier BV
Date: 08-2022
Publisher: Cambridge University Press (CUP)
Date: 10-1993
DOI: 10.1079/PNS19930083
Abstract: Older adults with visual impairments experience a higher risk of falling, and are more vulnerable to adverse health consequences associated with falls than those with normal vision. This study characterizes longitudinal changes in objectively measured physical activity and fear of falling (FoF) occurring after various types of falls in visually impaired older adults. Prospective cohort study. Hospital-based enrollment. People with glaucoma or suspected glaucoma. Falls were defined as unintentionally coming to rest on the ground or a lower level, and injurious falls were determined though follow-up calls. Study participants were categorized into three groups-fallers with injurious consequences, fallers without injurious consequences, and non-fallers based on fall status in the first year. Physical activity was assessed by waist-bound accelerometer. FoF was evaluated by questionnaire, with Rasch modeling generating FoF scores where higher scores reflected worse FoF. The 3-year longitudinal changes of physical activity and FoF were modeled using mixed-effects models. In linear models fully adjusted for visual field damage and other covariates, physical activity among injurious fallers showed greater annual (per year) declines in daily steps (-425 steps/d, 95% confidence interval (CI) = -793, -57), daily active minutes (-13 min/d, 95% CI = -21, -6), and daily moderate and vigorous physical activity (MVPA) minutes (-3 MVPA minutes/d, 95% CI = -5, 0) over the 3-year period as compared to non-fallers however, physical activity did not significantly decline among non-injurious fallers. No longitudinal increases in FoF scores were observed in injurious or non-injurious fallers when compared to non-fallers. Among visually impaired older adults, injurious falls identified prospectively over 12 months contributed to a significant decline in physical activity over a 3-year period, while minimal changes were observed in FoF.
Publisher: Cambridge University Press (CUP)
Date: 12-2008
DOI: 10.1017/S0954422408102414
Abstract: The present review examines renewable sources of oils with n -3 long-chain ( ≥ C 20 ) PUFA ( n -3 LC-PUFA) as alternatives to oil from wild-caught fish in aquafeeds. Due to the increased demand for and price of wild-caught marine sources of n -3 LC-PUFA-rich oil, their effective and sustainable replacement in aquafeeds is an industry priority, especially because dietary n -3 LC-PUFA from eating fish are known to have health benefits in human beings. The benefits and challenges involved in changing dietary oil in aquaculture are highlighted and four major potential sources of n -3 LC-PUFA for aquafeeds, other than fish oil, are compared. These sources of oil, which contain n -3 LC-PUFA, specifically EPA (20 : 5 n -3) and DHA (22 : 6 n -3) or precursors to these key essential fatty acids, are: (1) other marine sources of oil (2) vegetable oils that contain biosynthetic precursors, such as stearidonic acid, which may be used by fish to produce n -3 LC-PUFA (3) single-cell oil sources of n -3 LC-PUFA (4) vegetable oils derived from oil-seed crops that have undergone genetic modification to contain n -3 LC-PUFA. The review focuses on Atlantic salmon ( Salmo salar L.), because it is the main intensively cultured finfish species and it both uses and stores large amounts of oil, in particular n -3 LC-PUFA, in the flesh.
Publisher: Elsevier BV
Date: 08-1620
Publisher: Hindawi Limited
Date: 31-01-2003
Publisher: Wiley
Date: 06-07-2023
DOI: 10.1111/JFB.15499
Abstract: Fed aquaculture is one of the fastest growing and most valuable food production industries in the world. The efficiency with which farmed fish convert feed into biomass influences both environmental impact and economic revenue. Salmonid species, such as king salmon ( Oncorhynchus tshawytscha ), exhibit high levels of plasticity in vital rates such as feed intake and growth rates. Accurate estimations of in idual variability in vital rates are important for production management. The use of mean trait values to evaluate feeding and growth performance can mask in idual‐level differences that potentially contribute to inefficiencies . Here, we apply a cohort integral projection model (IPM) framework to investigate in idual variation in growth performance of 1625 in idually tagged king salmon fed one of three distinct rations of 60%, 80% and 100% satiation and tracked over a duration of 276 days. To capture the observed sigmoidal growth of in iduals, we compared a non‐linear mixed‐effects (logistic) model to a linear model used within the IPM framework. Ration significantly influenced several aspects of growth, both at the in idual and at the cohort level. Mean final body mass and mean growth rate increased with ration, however, variance in body mass and feed intake also increased significantly over time. Trends in mean body mass and in idual body mass variation were captured by both logistic and linear models, suggesting the linear model to be suitable for use in the IPM. We also observed that higher rations resulted in a decreasing proportion of in iduals reaching the cohort's mean body mass or larger by the end of the experiment. This suggests that, in the present experiment, feeding to satiation did not produce the desired effects of efficient, fast, and uniform growth in juvenile king salmon. While monitoring in iduals through time is challenging in commercial aquaculture settings, recent technological advances combined with an IPM approach could provide new scope for tracking growth performance in experimental and farmed populations. Using the IPM framework might allow the exploration of other size‐dependent processes affecting vital rate functions, such as competition and mortality. This article is protected by copyright. All rights reserved.
Publisher: Elsevier BV
Date: 02-2021
Publisher: CABI
Date: 2010
Publisher: Elsevier BV
Date: 09-1999
Publisher: Elsevier BV
Date: 08-2010
DOI: 10.1016/J.CBPA.2010.04.009
Abstract: The experiment aimed to measure post-prandial protein synthesis at three different temperatures. Juvenile barramundi (10.81+/-3.46 g) were held at 21, 27 and 33 degrees C and fed to satiation daily. S les were taken over a 24h period at 0 (24h after the previous meal) and then at 4, 8, 12 and 24h after feeding to measure protein synthesis in the white muscle, liver and remaining carcass. Protein synthesis at 27 and 33 degrees C peaked 4h after feeding in all tissues and returned to pre-feeding rates by 12h. At 21 degrees C protein synthesis remained constant over 24h in all tissues. While the concentration of RNA remained stable over the 24h cycle and across temperatures, the ribosomal activity increased after feeding. This meant k(RNA), not the absolute amount of RNA, was the driving force underlying the post-prandial increase in protein synthesis. However, relative differences in protein synthesis between tissues were attributed to differences in RNA concentration. There was a significant positive relationship between white muscle and whole body protein synthesis. This was the first study to show an interaction between temperature and the time after feeding on protein synthesis for an ectotherm, and that a post-prandial peak in protein synthesis only occurred under optimum temperature conditions.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Chris G. Carter.