ORCID Profile
0000-0002-8035-3417
Current Organisation
James Cook University
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Publisher: The Royal Society
Date: 26-08-2008
Abstract: Recent studies have shown that some coral reef fish larvae return to natal reefs, while others disperse to distant reefs. However, the sensory mechanisms used to find settlement sites are poorly understood. One hypothesis is that larvae use olfactory cues to navigate home or find other suitable reef habitats. Here we show a strong association between the clownfish Amphiprion percula and coral reefs surrounding offshore islands in Papua New Guinea. Host anemones and A. percula are particularly abundant in shallow water beneath overhanging rainforest vegetation. A series of experiments were carried out using paired-choice flumes to evaluate the potential role of water-borne olfactory cues in finding islands. Recently settled A. percula exhibited strong preferences for: (i) water from reefs with islands over water from reefs without islands (ii) water collected near islands over water collected offshore and (iii) water treated with either anemones or leaves from rainforest vegetation. Laboratory reared-juveniles exhibited the same positive response to anemones and rainforest vegetation, suggesting that olfactory preferences are innate rather than learned. We hypothesize that A. percula use a suite of olfactory stimuli to locate vegetated islands, which may explain the high levels of self-recruitment on island reefs. This previously unrecognized link between coral reefs and island vegetation argues for the integrated management of these pristine tropical habitats.
Publisher: The Oceanography Society
Date: 09-2007
Publisher: The Royal Society
Date: 21-06-2023
Abstract: Temporal patterns in spawning and juvenile recruitment can have major effects on population size and the demographic structure of coral reef fishes. For harvested species, these patterns are crucial in determining stock size and optimizing management strategies such as seasonal closures. For the commercially important coral grouper ( Plectropomus spp.) on the Great Barrier Reef, histological studies indicate peak spawning around the summer new moons. Here we examine the timing of spawning activity for P. maculatus in the southern Great Barrier Reef by deriving age in days for 761 juvenile fish collected between 2007 and 2022, and back-calculating settlement and spawning dates. Age-length relationships were used to estimate spawning and settlement times for a further 1002 juveniles collected over this period. Unexpectedly, our findings indicate year-round spawning activity generates distinct recruitment cohorts that span several weeks to months. Peak spawning varied between years with no clear association with environmental cues, and little to no alignment with existing seasonal fisheries closures around the new moon. Given the variability and uncertainty in peak spawning times, this fishery may benefit from additional and longer seasonal closures, or alternative fisheries management strategies, to maximize the recruitment contribution from periods of greatest reproductive success.
Publisher: Proceedings of the National Academy of Sciences
Date: 18-05-2004
Abstract: The worldwide decline in coral cover has serious implications for the health of coral reefs. But what is the future of reef fish assemblages? Marine reserves can protect fish from exploitation, but do they protect fish bio ersity in degrading environments? The answer appears to be no, as indicated by our 8-year study in Papua New Guinea. A devastating decline in coral cover caused a parallel decline in fish bio ersity, both in marine reserves and in areas open to fishing. Over 75% of reef fish species declined in abundance, and 50% declined to less than half of their original numbers. The greater the dependence species have on living coral as juvenile recruitment sites, the greater the observed decline in abundance. Several rare coral-specialists became locally extinct. We suggest that fish bio ersity is threatened wherever permanent reef degradation occurs and warn that marine reserves will not always be sufficient to ensure their survival.
Publisher: Zenodo
Date: 2018
Publisher: Inter-Research Science Center
Date: 18-11-2009
DOI: 10.3354/MEPS08294
Publisher: Springer Science and Business Media LLC
Date: 14-09-2006
Publisher: Wiley
Date: 28-06-2019
DOI: 10.1111/EMR.12381
Publisher: The Royal Society
Date: 21-11-2018
Abstract: In social groups, high reproductive skew is predicted to arise when the reproductive output of a group is limited, and dominant in iduals can suppress subordinate reproductive efforts. Reproductive suppression is often assumed to occur via overt aggression or the threat of eviction. It is unclear, however, whether the threat of eviction alone is sufficient to induce reproductive restraint by subordinates. Here, we test two assumptions of the restraint model of reproductive skew by investigating whether resource limitation generates reproductive competition and whether the threat of eviction leads to reproductive restraint in the clown anemonefish Amphiprion percula . First, we use a feeding experiment to test whether reproduction is resource limited, which would create an incentive for the dominant pair to suppress subordinate reproduction. We show that the number of eggs laid increased in the population over the study period, but the per cent increase in fed groups was more than twice that in unfed groups (205% and 78%, respectively). Second, we use an eviction experiment to test whether the dominant pair evicts mature subordinates, which would create an incentive for the subordinates to forgo reproduction. We show that mature subordinates are seven times more likely to be evicted than immature subordinates of the same size. In summary, we provide experimental support for the assumptions of the restraint model by showing that resource limitation creates reproductive competition and a credible threat of eviction helps explain why subordinates forego reproduction. Transactional models of reproductive skew may apply well to this and other simple systems.
Publisher: Inter-Research Science Center
Date: 1999
DOI: 10.3354/MEPS186283
Publisher: Wiley
Date: 08-08-2012
Publisher: Inter-Research Science Center
Date: 08-08-2012
DOI: 10.3354/MEPS09788
Publisher: Springer Science and Business Media LLC
Date: 05-05-2020
Publisher: Springer Science and Business Media LLC
Date: 03-12-2008
Publisher: Elsevier BV
Date: 06-2012
DOI: 10.1016/J.CUB.2012.04.008
Abstract: Marine reserves, areas closed to all forms of fishing, continue to be advocated and implemented to supplement fisheries and conserve populations. However, although the reproductive potential of important fishery species can dramatically increase inside reserves, the extent to which larval offspring are exported and the relative contribution of reserves to recruitment in fished and protected populations are unknown. Using genetic parentage analyses, we resolve patterns of larval dispersal for two species of exploited coral reef fish within a network of marine reserves on the Great Barrier Reef. In a 1,000 km(2) study area, populations resident in three reserves exported 83% (coral trout, Plectropomus maculatus) and 55% (stripey snapper, Lutjanus carponotatus) of assigned offspring to fished reefs, with the remainder having recruited to natal reserves or other reserves in the region. We estimate that reserves, which account for just 28% of the local reef area, produced approximately half of all juvenile recruitment to both reserve and fished reefs within 30 km. Our results provide compelling evidence that adequately protected reserve networks can make a significant contribution to the replenishment of populations on both reserve and fished reefs at a scale that benefits local stakeholders.
Publisher: Wiley
Date: 10-11-2011
DOI: 10.1002/ECE3.53
Publisher: Public Library of Science (PLoS)
Date: 13-05-2015
Publisher: Springer Science and Business Media LLC
Date: 08-05-2017
Abstract: Larval dispersal is a critical yet enigmatic process in the persistence and productivity of marine metapopulations. Empirical data on larval dispersal remain scarce, hindering the use of spatial management tools in efforts to sustain ocean bio ersity and fisheries. Here we document dispersal among subpopulations of clownfish (Amphiprion percula) and butterflyfish (Chaetodon vagabundus) from eight sites across a large seascape (10,000 km
Publisher: Elsevier BV
Date: 10-2013
Publisher: Proceedings of the National Academy of Sciences
Date: 31-10-2016
Abstract: Evidence for natal philopatry, the return of in iduals to their natal location for reproduction, is scarce in marine fish populations despite being common in anadromous fishes. The proportion of in iduals returning to natal sites is an important metric for estimating the effects of inbreeding and the potential for local adaptation to generate resilience to climate change. Here, we present the first multigenerational pedigree for a wild marine fish. We resolved the genealogical tree of families of orange clownfish Amphiprion percula spanning up to five generations, using data from a 10-year genetic survey of a population at Kimbe Island, Papua New Guinea. We found that longitudinal philopatry plays a significant role in driving population renewal of the orange clownfish.
Publisher: Springer Science and Business Media LLC
Date: 10-2022
DOI: 10.1007/S00227-022-04117-9
Abstract: Social hierarchies within groups define the distribution of resources and provide benefits that support the collective group or favor dominant members. The progression of in iduals through social hierarchies is a valuable characteristic for quantifying population dynamics. On coral reefs, some clownfish maintain size-based hierarchical communities where in iduals queue through social ranks. The cost of waiting in a lower-ranked position is outweighed by the reduced risk of eviction and mortality. The orange clownfish, Amphiprion percula , maintains stable social groups with subordinate in iduals queuing to be part of the dominant breeding pair. Strong association with their host anemone, complex social interactions, and relatively low predation rates make them ideal model organisms to assess changes in group dynamics through time in their natural environment. Here, we investigate the rank changes and isometric growth rates of A. percula from 247 naturally occurring social groups in Kimbe Island, Papua New Guinea (5° 12′ 13.54″ S, 150° 22′ 32.69″ E). We used DNA profiling to assign and track in iduals over eight years between 2011 and 2019. Over half of the in iduals survived alongside two or three members of their original social group, with twelve breeding pairs persisting over the study period. Half of the surviving in iduals increased in rank and experienced double the growth rate of those that maintained their rank. Examining rank change in a wild fish population provides new insights into the complex social hierarchies of reef fishes and their role in social evolution.
Publisher: CSIRO Publishing
Date: 2007
DOI: 10.1071/MF07019
Abstract: Competition theory predicts that, when resources are limiting, interacting species should differ more in resource use where they co-occur, compared with where they do not (resource partitioning). The damselfishes Dascyllus aruanus and D. melanurus provide a useful test of this prediction because they exhibit largely allopatric geographic ranges that overlap near Port Moresby, Papua New Guinea. To test whether this species pair exhibited responses in resource use that were consistent with competition theory, the depth distributions, coral substrata and diet of each species at allopatric and sympatric locations were compared. Where sympatric, the frequency of co-occurrence was examined and foraging ranges and diet on corals where the species do and do not co-occur were compared. Contrary to expectations, the species were more similar in depth, habitat use and diet in the sympatric region. Within this location, they sometimes co-existed in the same coral shelters, but much less often than would be expected with random assortment. Where they did co-exist, their diets converged. D. melanurus exhibited restricted foraging ranges and consumed smaller prey in the presence of D. aruanus, but not vice versa. It was concluded that niche shifts along different resource axes at the geographic boundary are explained both by large-scale constraints in resource availability and local-scale competitive interactions.
Publisher: PeerJ
Date: 06-11-2018
DOI: 10.7717/PEERJ.5841
Abstract: The size and structure of social groups of animals can be governed by a range of ecological factors and behavioral interactions. In small, highly site-attached coral reef fishes, group size is often constrained by the size of the habitat patch they are restricted to. However, group size may also be influenced by changes in abundance along important environmental gradients, such as depth or distance offshore. In addition, the body size and sex structure within social groups can be determined by the size of the habitat patch and the dominance relationships among group members. Here we examined the roles of ecological factors and behavioral interactions in governing group size and structure in the orange clownfish, Amphiprion percula, on inshore reefs in Kimbe Bay, Papua New Guinea. We quantified relationships between ecological variables (anemone size, depth, and distance from shore) and social group variables (group size, and total body length of the three largest in iduals (ranks 1, 2, and 3)). Anemone size explained the greatest amount of variation in group variables, with strong, positive relationships between anemone surface area and group size, and total length of in iduals ranked 1, 2, and 3. Group structure was also weakly correlated with increasing depth and distance from shore, most likely through the indirect effects of these environmental gradients on anemone size. Variation in group size and the lengths of ranks 2 and 3 were all closely related to the length of rank 1. Path analysis indicated that anemone size has a strong direct effect on the length of rank 1. In turn, the length of rank 1 directly affects the size of the subordinate in iduals and indirectly affects the group size through its influence on subordinates. Hence, anemone size directly and indirectly controls social group size and structure in this space-limited fish species. It is also likely that anemonefish have feedback effects on anemone size, although this could not be differentiated in the path analysis.
Publisher: Wiley
Date: 26-11-2020
DOI: 10.1111/ELE.13428
Abstract: The relative contributions of environmental, maternal and additive genetic factors to the Lifetime reproductive success (LRS) determine whether species can adapt to rapid environmental change. Yet to date, studies quantifying LRS across multiple generations in marine species in the wild are non-existent. Here we used 10-year pedigrees resolved for a wild orange clownfish population from Kimbe Island (PNG) and a quantitative genetic linear mixed model approach to quantify the additive genetic, maternal and environmental contributions to variation in LRS for the self-recruiting portion of the population. We found that the habitat of the breeder, including the anemone species and geographic location, made the greatest contribution to LRS. There were low to negligible contributions of genetic and maternal factors equating with low heritability and evolvability. Our findings imply that our population will be susceptible to short-term, small-scale changes in habitat structure and may have limited capacity to adapt to these changes.
Publisher: Springer Science and Business Media LLC
Date: 09-2003
DOI: 10.1007/S00442-003-1320-6
Abstract: Many coral reef fishes have restricted depth ranges that are established at settlement or soon after, but the factors limiting these distributions are largely unknown. This study examines whether the availability of microhabitats (reef substrata) explains depth limits, and evaluates whether juvenile growth and survival are lower beyond these limits. Depth-stratified surveys of reef fishes at Kimbe Bay (Papua New Guinea) showed that the abundance of new settlers and the cover of coral substrata differed significantly among depths. A field experiment investigated whether settling coral reef fishes preferred particular depths, and whether these depth preferences were dependent on microhabitat. Small patch reefs composed of identical coral substrata were set up at five depths (3, 6, 10, 15 and 20 m), and settlement patterns were compared to those on unmanipulated reef habitat at the same five depths. For all species, settlement on patch reefs differed significantly among depths despite uniform substratum composition. For four of the six species tested, depth-related settlement patterns on unmanipulated habitat and on patch reefs did not differ, while for the other two, depth ranges were greater on the patch reefs than on unmanipulated habitat. A second experiment examined whether depth preferences reflected variation in growth and survival when microhabitat was similar. Newly settled in iduals of Chrysiptera parasema and Dascyllus melanurus were placed, separately, on patch reefs at five depths (as above) and their survival and growth monitored. D. melanurus, which is restricted to shallow depths, had highest survival and growth at the shallowest depth. Depth did not affect either survival or growth of C. parasema, which has a broader depth range than D. melanurus (between 6 and 15 m). This suggests that the fitness costs potentially incurred by settling outside a preferred depth range may depend on the strength of the depth preference.
No related grants have been discovered for Maya Srinivasan.