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Michael J. Kingsford - One of the best experts on this subject based on the ideXlab platform.
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contrasting patterns of reef utilization and recruitment of coral trout plectropomus Leopardus and snapper lutjanus carponotatus at one tree island southern great barrier reef
Coral Reefs, 2009Co-Authors: Michael J. KingsfordAbstract:Patterns of abundance, age structure and recruitment of coral trout (Plectropomus Leopardus) and snapper (Lutjanus carponotatus) were described in different environments, which varied in benthic cover, in a 12-yr study at One Tree Island. It was hypothesized that both taxa would show strong preferences to different environments and benthic cover and that patterns would be consistent through time. Plectropomus Leopardus were abundant on the reef slope and seaward edge of the lagoon, where live coral cover was high, and recruitment was generally low, in all environments. The population was sustained by a trickle of recruits, and total abundance varied little after 10 to 25 yr of protection in a no-take area, suggesting P. Leopardus had reached an environment-related carrying capacity. Protogynous P. Leopardus recruited to shallow environments at sites with 20% or more hard live coral and age data indicated the abundance of fish on the reef slope was from redistribution. Most recruits of gonochoristic L. carponotatus (<150 mm Standard length, SL) were found in the lagoonal environments, and adults were rare on the reef slope. Abundance of recruit L. carponotatus and P. Leopardus did not correlate with percent cover of live and soft coral within environments. Recruits of L. carponotatus were usually rare in all lagoonal environments, but in 2003, many recruits (80 to 120 mm SL) were found in lagoonal environments with low and high hard live coral cover. A substantial proportion of the population (age max 18 yr) was from strong recruitment events. In 2003 and 2004, total abundance of L. carponotatus was supported by 1 year class 51.7 and 41% respectively. The utilization of environments and types of substrata varied among taxa and in some cases among life-history stages. There was also temporal variation in the importance of some environments (e.g. Lagoon Centre).
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Contrasting patterns of reef utilization and recruitment of coral trout (Plectropomus Leopardus) and snapper (Lutjanus carponotatus) at One Tree Island, southern Great Barrier Reef
Coral Reefs, 2008Co-Authors: Michael J. KingsfordAbstract:Patterns of abundance, age structure and recruitment of coral trout (Plectropomus Leopardus) and snapper (Lutjanus carponotatus) were described in different environments, which varied in benthic cover, in a 12-yr study at One Tree Island. It was hypothesized that both taxa would show strong preferences to different environments and benthic cover and that patterns would be consistent through time. Plectropomus Leopardus were abundant on the reef slope and seaward edge of the lagoon, where live coral cover was high, and recruitment was generally low, in all environments. The population was sustained by a trickle of recruits, and total abundance varied little after 10 to 25 yr of protection in a no-take area, suggesting P. Leopardus had reached an environment-related carrying capacity. Protogynous P. Leopardus recruited to shallow environments at sites with 20% or more hard live coral and age data indicated the abundance of fish on the reef slope was from redistribution. Most recruits of gonochoristic L. carponotatus (
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Spatial and temporal variation in predation on reef fishes by coral trout ( Plectropomus Leopardus , Serranidae)
Coral Reefs, 1992Co-Authors: Michael J. KingsfordAbstract:The diet of coral trout Plectropomus Leopardus (Serranidae) was studied over a two year period at One Tree Island, Great Barrier Reef, Australia. Rapid visual counts demonstrated that P. Leopardus were most abundant on the reef slope habitat and inner edge of the enclosed lagoon. Few P. Leopardus were found at sites from “inner” lagoon. It was hypothesized that diet would vary among habitats, times and size classes of coral trout. Ninety-two percent of P. Leopardus that contained prey had consumed fish and 87% had only eaten fish. Many types of reef fish were taken by P. Leopardus (e.g. Pomacentridae, Scaridae, Blenniidae and Labridae). Most pelagic prey (Clupeidae and Engraulididae) were taken on the reef slope, while some prey were solely or pimarily taken in the lagoon (e.g. Blenniidae and crustaceans). Most pelagic prey were taken on the reef slope in summer by P. Leopardus>250 mm (SL). Plectropomus Leopardus (
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spatial and temporal variation in predation on reef fishes by coral trout plectropomus Leopardus serranidae
Coral Reefs, 1992Co-Authors: Michael J. KingsfordAbstract:The diet of coral trout Plectropomus Leopardus (Serranidae) was studied over a two year period at One Tree Island, Great Barrier Reef, Australia. Rapid visual counts demonstrated that P. Leopardus were most abundant on the reef slope habitat and inner edge of the enclosed lagoon. Few P. Leopardus were found at sites from “inner” lagoon. It was hypothesized that diet would vary among habitats, times and size classes of coral trout. Ninety-two percent of P. Leopardus that contained prey had consumed fish and 87% had only eaten fish. Many types of reef fish were taken by P. Leopardus (e.g. Pomacentridae, Scaridae, Blenniidae and Labridae). Most pelagic prey (Clupeidae and Engraulididae) were taken on the reef slope, while some prey were solely or pimarily taken in the lagoon (e.g. Blenniidae and crustaceans). Most pelagic prey were taken on the reef slope in summer by P. Leopardus>250 mm (SL). Plectropomus Leopardus (<200 mm) from the lagoon had a higher proportion of invertebrates in the diet than fish from the reef slope. Plectropomus Leopardus of all sizes ate small fish, while largest fish generally consumed largest prey (especially adult scarids and labrids). I argue that interactions among multiple species of prey and predators need more attention, because piscivores may respond to prey in different ways according to habitat type as well as the number and type of other prey types present. Furthermore, different sizes of fish (e.g. coral trout) may impact assemblages of prey in different ways.
Ashley J. Frisch - One of the best experts on this subject based on the ideXlab platform.
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Effects of climate change on coral grouper (Plectropomus spp.) and possible adaptation options
Reviews in Fish Biology and Fisheries, 2017Co-Authors: Morgan S. Pratchett, Ashley J. Frisch, Darren S. Cameron, Andrew S. Hoey, Louisa Evans, Jennifer Donelson, Alistair J. Hobday, Nadine A. Marshall, Vanessa Messmer, Philip L. MundayAbstract:Global climate change is increasingly considered one of the major threats to tropical coastal fisheries, potentially undermining important revenue and food security provided by coral reef ecosystems. While there has been significant and increasing work on understanding specific effects of climate change on coral reef fishes, few studies have considered large-bodied fisheries target species, limiting understanding of the effects of climate change on tropical fisheries. This review focuses on coral grouper ( Plectropomus spp., and mainly Plectropomus Leopardus ), which are heavily fished throughout the Indian and Pacific oceans, and represent an exemplar group to assess potential effects of climate change on coral reef fisheries. In experimental studies, P. Leopardus appear to be extremely sensitive to increasing ocean temperature, exhibiting declines in survivorship, aerobic scope and activity with relatively moderate increases in temperature. As such, ongoing ocean warming may jeopardize the catchability of coral grouper and sustainability of reef-based fisheries, especially at low latitudes. Notably, a significant portion of wild stocks of P. Leopardus are already exposed to temperatures (≥30 °C) that have been shown to compromise individual performance and body condition. While there are considerable knowledge gaps in predicting effects of global climate change on coral grouper, such as their capacity to avoid, acclimate or adapt to changes in local environmental conditions, current information suggests that there is cause for concern. As such, we take the formative steps to outline both ecological and socioeconomic adaptations that could reduce vulnerability of coral reef fisheries to climate impacts on stocks of coral grouper, using a linked socio-economic framework.
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Evaluating the effectiveness of teeth and dorsal fin spines for non-lethal age estimation of a tropical reef fish, coral trout Plectropomus Leopardus.
Journal of fish biology, 2014Co-Authors: Jean-paul A. Hobbs, Ashley J. Frisch, S. Mutz, Benjamin M. FordAbstract:This study investigated whether teeth and dorsal fin spines could be used as non-lethal methods of age estimation for a vulnerable and highly valued tropical fisheries species, coral trout Plectropomus Leopardus. Age estimation of individuals from 2 to 9 years old revealed that dorsal spines represent an accurate ageing method (90% agreement with otoliths) that was more precise [average per cent error (APE) = 4·1, coefficient of variation (c.v.) = 5·8%] than otoliths (APE = 6·2, c.v. = 8·7%). Of the three methods for age estimation (otoliths, dorsal spines and teeth), spines were the most time and cost efficient. An aquarium-based study also found that removing a dorsal spine or tooth did not affect survivorship or growth of P. Leopardus. No annuli were visible in teeth despite taking transverse and longitudinal sections throughout the tooth and trialling several different laboratory methods. Although teeth may not be suitable for estimating age of P. Leopardus, dorsal spines appear to be an acceptably accurate, precise and efficient method for non-lethal ageing of individuals from 2 to 9 years old in this tropical species.
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trophic ecology of large predatory reef fishes energy pathways trophic level and implications for fisheries in a changing climate
Marine Biology, 2014Co-Authors: Ashley J. Frisch, Matthew Ireland, Ronald BakerAbstract:Large predatory fishes are disproportionately targeted by reef fisheries, but little is known about their trophic ecology, which inhibits understanding of community dynamics and the potential effects of climate change. In this study, stable isotope analyses were used to infer trophic ecology of a guild of large predatory fishes that are targeted by fisheries on the Great Barrier Reef, Australia. Each of four focal predators (Plectropomus Leopardus, Plectropomus maculatus, Lethrinus miniatus and Lutjanus carponotatus) was found to have a distinct isotopic signature in terms of δ13C and δ15N. A two-source mixing model (benthic reef-based versus pelagic) indicated that P. Leopardus and L. miniatus derive the majority (72 and 62 %, respectively) of their production from planktonic sources, while P. maculatus and L. carponotatus derive the majority (89 and 74 %, respectively) of their production from benthic reef-based sources. This indicates that planktonic production is important for sustaining key species in reef fisheries and highlights the need for a whole-ecosystem approach to fisheries management. Unexpectedly, there was little isotopic niche overlap between three of four focal predators, suggesting that inter-specific competition for prey may be low or absent. δ15Nitrogen indicated that the closely related P. Leopardus and P. maculatus are apex predators (trophic level > 4), while δ13C indicated that each species has a different diet and degree of trophic specialisation. In view of these divergent trophic ecologies, each of the four focal predators (and the associated fisheries) are anticipated to be differentially affected by climate-induced disturbances. Thus, the results presented herein provide a useful starting point for precautionary management of exploited predator populations in a changing climate.
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Reproductive periodicity and steroid hormone profiles in the sex-changing coral-reef fish, Plectropomus Leopardus
Coral Reefs, 2007Co-Authors: Ashley J. Frisch, Mark I. Mccormick, Neville William PankhurstAbstract:The reproductive biology of coral trout, Plectropomus Leopardus, from the Great Barrier Reef (Australia) was investigated by correlating gonadal condition with plasma levels of gonadal steroids. Female fish were found to be regressed from mid-summer to early spring, after which rapid and cyclical increases in gonado-somatic index (IG), maximum oocyte diameter (MOD) and plasma concentrations of estradiol-17β and testosterone were detected. Male fish, in contrast, commenced recrudescence slightly earlier in winter and responded with less dramatic increases in both IG and plasma concentrations of testosterone and 11-ketotestosterone. The mode of oocyte development was multiple group-synchronous, and cyclical fluctuations in reproductive parameters (IG, MOD and gonadal steroid concentrations) were synchronized with new-moon lunar phases. It is likely, therefore, that individual P. Leopardus have the capacity to spawn on multiple occasions, with lunar periodicity. However, evidence suggests that early bouts of reproduction may be more important in terms of reproductive investment than subsequent bouts later in the same season. It is concluded that patterns of gametogenesis and steroidogenesis in P. Leopardus are similar to the patterns displayed by other tropical groupers, suggesting that management regimes and propagation protocols developed for these fishes may also be appropriate for use with P. Leopardus.
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contrasting patterns of genetic structure in two species of the coral trout plectropomus serranidae from east and west australia introgressive hybridisation or ancestral polymorphisms
Molecular Phylogenetics and Evolution, 2006Co-Authors: L Van Herwerden, John Howard Choat, Ashley J. Frisch, Christine L Dudgeon, G Carlos, Stephen J Newman, M J H Van OppenAbstract:Inter-specific genetic relationships among regional populations of two species of grouper (Plectropomus maculatus and Plectropomus Leopardus) were examined using mitochondrial and nuclear markers. mtDNA revealed contrasting regional inter-specific patterns whilst nuclear markers revealed contrasting patterns among markers, irrespective of region. In eastern Australia (EA) the species form a single mtDNA lineage, but the two species are reciprocally monophyletic in Western Australia (WA). This supports previous evidence for hybridisation between these species on the east coast. WA P. Leopardus forms a sister relationship with the EA P. Leopardus-maculatus clade while WA P. maculatus is more basal and sister to the P. Leopardus lineages, indicating mtDNA does not suffer from incomplete lineage sorting for these species. In contrast, one of three nuclear markers (locus 7-90TG) differentiated the species into two reciprocally monophyletic clades, with no evidence of hybridisation or ancestral polymorphism. The remaining two nuclear markers (2-22 and ETS-2) did not separate these two species, while distinguishing other plectropomid species, suggesting incomplete lineage sorting at these nuclear loci. These results together with coalescence analyses suggest that P. Leopardus females have hybridised historically with P. maculatus males and that P. maculatus mitochondria were displaced through introgressive hybridisation and fixation in the P. maculatus founder population on the Great Barrier Reef. The contrasting regional patterns of mtDNA structure may be attributed to Quaternary sea-level changes and shelf width differences driving different reef configurations on each coast. These reef configurations have provided opportunities for local scale interaction and reproduction among species on the narrower EA continental shelves, but not on the broader WA continental shelves.
Jill St John - One of the best experts on this subject based on the ideXlab platform.
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The diet of the large coral reef serranid Plectropomus Leopardus in two fishing zones on the Great Barrier Reef, Australia
2001Co-Authors: Jill St John, Garry R. Russ, Ian W. Brown, Lyle C. SquireAbstract:The diet of Plectropomus Leopardus (Serranidae, Lacepede 1802) was examined on two pairs of reefs in the Cairns Section of the Great Barrier Reef Marine Park, Australia. For both pairs, one reef was open to fishing and the other had been closed to fishing for eight years; however zoning appeared to be ineffective as there was no difference in the size structure of leopard coral grouper populations on either open or closed reefs. Two fishing methods were used to sample reefs concurrently, and the size structure and diet of P. Leopardus that were speared randomly (n=587) were compared to samples caught by line (n=85). Adult P. Leopardus were highly piscivorous (96% of prey was fish by number), and two families of fishes, Pomacentridae and Labridae, composed approximately half of their diet (index of relative importance= 48.4%). Numerical composition of fish in the diet varied significantly among reefs, but there were no patterns related to reef closures when fish prey were classified by taxa or by their habitat. Fishes categorized as living in the demersal reef habitat were the dominant prey consumed, followed by midwater fishes. When the data from reefs were pooled, the abundance of families in the diet differed between locations (north and south) but not between fishing zones. Dietary overlap was high between the different fishing zones and was very high in relation to naturally occurring spatial and temporal variability in the diet of P. Leopardus found in other studies. With line fishing larger and hungry fish are caught, and the few data on natural prey suggest tentatively that line catches are biased toward P. Leopardus feeding on pelagic fishes. The coral reefs and surrounding waters provide the major food source of P. Leopardus, whereas sandy areas are much less important. Our data suggest that the coral trout fishery is resilient to changes in abundances of particular prey species because the diet of P. Leopardus is broad and because the two major prey families are diverse and abundant on coral reefs.
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Ontogenetic changes in the diet of the coral reef grouper Plectropomus Leopardus (Serranidae):patterns in taxa, size and habitat of prey
Marine Ecology Progress Series, 1999Co-Authors: Jill St JohnAbstract:Stomach contents and diet of a wide range of sizes (4.7 to 57.3 cm standard length [SL]) of the predatory coral trout Plectropomus Leopardus (Fam. Serranidae) collected mostly from the northern Great Barrier Reef during the summers of 1991 and 1992 were examined. Overall, 422 prey in 28 families of fishes were identified of which 3 families, Clupeidae, Pomacentridae and Labridae, represented more than 60% of the diet. Average daily consumption of prey in P Leopardus was 2.8% of relative body weight and fish of 20 to 49.9 mm SL were eaten by all size classes. Juvenile (up to 20 cm SL) and adult P. Leopardus have distinct diets. The major dietary shift in the type, species composition, length and shape of prey occurs at approximately 20 cm SL, just prior to the onset of maturity. Juveniles consumed a high proportion of benthic dwelling crustaceans, mostly penaeid shrimps, whereas adults were almost entirely piscivorous. The number of families of fishes in the diet did not increase with the size of predator as some families were eaten exclusively by juveniles or adults. Abundances of fish families in the diet varied ontogenetically and among size classes in small adults. Predation was related to size of prey in juvenile and small adults. Up to 35 cm SL, the range of prey sizes widened with increases in predator length, as larger fish ate larger prey, concomitantly feeding on small fishes, especially schooling species. However, the composition of the diet and length of fish prey did not change in P. Leopardus after 35 cm SL and prey did not deepen after 45 cm SL. Body depth of prey was more important than length in size-related feeding on 2 common families of fishes with different shapes. In general, larger P. Leopardus appeared to feed optimally on deep-bodied fish, whereas juveniles avoided gape limitation by consuming more slender fish. All size-related predation in P. Leopardus, however, was easily decoupled by the presence of highly abundant small fishes in large visible schools.
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Feeding ecology of the coral trout, Plectropomus Leopardus (Serranidae), on the Great Barrier Reef, Australia
1995Co-Authors: Jill St JohnAbstract:The Great Barrier Reef (GBR) is the largest coral reef system in the world and the coral trout, Plectropomus Leopardus (Pisces: Serranidae, Lacepede 1802) is one of its most widespread and abundant piscivores (Ayling and Ayling 1986). Despite the importance of the coral trout fishery, very little is known about the feeding ecology of P. Leopardus on the GBR. The principal objective of this study was to describe the diet and feeding of P. Leopardus on this large reef system. Variation in the diet of this piscivore over a range of latitudes along the GBR and on reefs open and closed to fishing was examined. Seasonality of feeding by P. Leopardus was addressed by comparing rates of digestion, consumption of food and diet in the austral summer and winter. Within populations of P. Leopardus, the ontogenetic shifts in diet and individual feeding behaviour were examined. Plectropomus Leopardus is one of the major predators of adult coral reef fishes on the GBR. After their first year of life, P. Leopardus are almost entirely piscivorous oh adult fishes (99% of fish diet). The dominance of fish in the diet does not vary temporally or spatially. Feeding studies have shown that P. Leopardus are intermittent feeders, consuming an average of one prey item daily. After 24 hours, approximately 90% of prey items were digested. Thus, contents of stomachs represented daily feeding in P. Leopardus. Seasonal rates of food consumption were not related to rates of digestion in P. Leopardus. In P. Leopardus, the major dietary shift in the type, species composition, length and shape of prey occurred at approximately 20 cm SL and corresponded to the onset of sexual maturity. Juvenile P. Leopardus consumed a higher proportion of benthic crustaceans, mostly penaeid prawns. Though families of prey fish in the diet varied ontogenetically, the breadth of the diet (in terms of family richness) did not increase with the size of predator. This shift in diet must be due to a change in feeding behaviour because juvenile P. Leopardus live in similar habitats to adults. Overall, Pomacentridae were the dominant family in the diet of P. Leopardus. The main families in the diet of P. Leopardus were divided into two groups. Common families (Pomacentridae, Labridae, Caesionidae and Scaridae) constituted a consistent and substantial portion of the diet. Small schooling fishes (e.g. Clupeidae), were a highly variable component of the diet both temporally and spatially. Sporadic appearances of small schooling prey in the diet of P. Leopardus were the main cause of the reduction in dietary overlap between reefs and times. The abundance of prey in three common families varied latitudinally in the diet of P. Leopardus . Pomacentridae and Caesionidae were consumed more in the northern GBR whereas Scaridae were eaten more in the south. There were no detectable effects of fishing on the diet of P. Leopardus. Dietary overlap among reefs zoned for different levels of fishing were within natural spatial and temporal variations for.the GBR. Most of the major changes in the diet of P. Leopardus occurred before the piscivores entered the . fishery (current legal minimum size is 38 cm FL). Adult P. Leopardus prey on juvenile Plectropomus spp. and thus high densities of adults may reduce abundances of juveniles. The major seasonal difference in feeding was a higher consumption of food in winter that coincided with increased production of mesenteric fat that is stored in preparation for reproduction (Ferreira 1993). Family richness in the diet increased during winter months because rare prey were consumed to meet a higher requirement for food. Otherwise, composition of the diet did not vary seasonally. Plectropomus Leopardus did not appear to respond to the seasonal influx of recruits to the reef during summer; newly recruited prey individuals were consumed rarely. Plectropomus Leopardus appear to be selective feeders in terms of both families and species of prey. At a family level, 37 families were identified in the stomachs of P. Leopardus. Many abundant families of fishes on the GBR (e.g. Chaetodontidae, Holocentridae, Pomacanthidae and Siganidae) were rarely eaten while others (e.g. Haemulidae) were not identified in the diet at all. The choice of species among the Pomacentridae was examined. Approximately 25% of the 120 possible species of Pomacentridae were identified in the stomachs of P. Leopardus. Some of these prey species were eaten in much higher proportions than expected when compared to their general abundance on reefs (e.g. Acanthochromis polyacanthus) whereas other species were eaten in much lower proportions (e.g Pomacentrus amboinensis, Pomacentrus moluccensis and Neopomacentrus azysron). The abundance of families (measured by digested weight) in the diet of P. Leopardus was compared to the biomass of prey fishes on another midshelf reef on the Central GBR (Williams and Hatcher 1983). The top five ranked families in the diet of P. Leopardus (Pomacentridae, Caesionidae, Scaridae, Labridae and Serranidae) were also the top five families in terms of biomass on reefs. Furthermore, these five families represented approximately 80% of both fishes on reefs and the total biomass of the prey in the diet. Prey in families were not eaten in exactly the same ranking as biomass on reefs. There was a large difference between the proportions of the two major prey species, Pomacentridae and Caesionidae, on midshelf reefs. Plectropomus Leopardus consumed more Pomacentridae than Caesionidae even though the biomass of Caesionidae on the reef was more than double that of Pomacentridae. The modes of life of schooling, mobile Caesionidae and demersal, site attached Pomacentridae differ on coral reefs and this may explain the reversal of ranks of these two families in the diet of P. Leopardus. In general, the size of prey and composition of the diet P. Leopardus was related to the size of the predator. As the gape of P. Leopardus limits the size of prey ingested, the critical dimension of the prey is depth rather than length. When feeding on larger prey items, small to medium-sized P. Leopardus (< 35 cm SL) appear to feed optimally as defined by Werner (1974) with respect to body-depth of prey. This size-related feeding did not occur under all circumstances. Size of prey was decoupled from size of predators for all P. Leopardus larger than 35 cm (SL) and when the prey were small schooling fishes. It appears that P. Leopardus switch to feeding on small schooling fishes when they are available. Predatory behaviour of P. Leopardus in tanks was highly variable among individuals. Both the success of capture of Acanthochromis polyacanthus (F. Pomacentridae) and the consistency of predatory abilities varied among individuals. Individual variation in feeding may help explain the high variability in growth and fecundity of individuals observed within populations of P. Leopardus (Ferreira 1993; Davies 1995). The abundance and species richness of the families common in the diet of P. Leopardus suggests that food for the coral trout fishery is sufficient on the GBR. Furthermore, feeding by P. Leopardus appears to be unaffected by this human activity at present levels of fishing. Other aspects of this study, however, suggest that fishery managers cannot be complacent. The effects of cannibalism within the fishery need to be understood. Fishing may reduce predation on prey on reefs directly by removing predators and, in the case of line fishing, indirectly by feeding predators. Data from the fishery should be treated with caution for two reasons. Firstly, Catch Per Unit Effort (fish per fisher per hour) was considered a poor method to estimate or compare the population density of P. Leopardus as more of the catch was taken by line when a high proportion of the population was hungry. Secondly, line fished samples of P. Leopardus should not be used for dietary studies as the abundance and composition of prey was biased by regurgitation and the presence of bait. Line caught fish had fewer natural prey in their stomachs and the composition of the natural diet differed from the sample caught by spear. In conclusion, the major sources of variability in the diet and feeding behaviour of P. Leopardus were the following: 1. ontogenetic shift from juveniles to adults, 2. high individual variation in successful capture of prey, and 3. regional variation in the diet. In contrast, seasonality and varying levels of fishing had little effect on the diet of P. Leopardus.
Grethe Hillersøy - One of the best experts on this subject based on the ideXlab platform.
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Complex patterns of population structure and recruitment of Plectropomus Leopardus (Pisces: Epinephelidae) in the Indo-West Pacific: implications for fisheries management
Marine Biology, 2009Co-Authors: Lynne Van Herwerden, John Howard Choat, Stephen J Newman, Matthieu Leray, Grethe HillersøyAbstract:Here the population genetic structure of an ecologically and economically important coral reef fish, the coral trout Plectropomus Leopardus, is investigated in the context of contemporary and historical events. Coral trout were sampled from four regions (six locations) and partial mtDNA D-loop sequences identified six populations (Fst = 0.89209, P < 0.0001): Scott Reef and the Abrolhos Islands in west Australia; the Great Barrier Reef (GBR), represented by northern and southern GBR samples; New Caledonia and Taiwan, with Taiwan containing two genetic lineages. Furthermore, this study identified source and sink populations within and among regions. Specifically, the northern population in west Australia (Scott Reef) was identified, as the source for replenishment of the Abrolhos population, whilst New Caledonia was a source for recruitment to the GBR. Based on these insights from a single mtDNA marker, this study will facilitate the development of rational management plans for the conservation of P. Leopardus populations and therefore mitigate the risk of population declines from anthropogenic influences.
Stephen J Newman - One of the best experts on this subject based on the ideXlab platform.
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Complex patterns of population structure and recruitment of Plectropomus Leopardus (Pisces: Epinephelidae) in the Indo-West Pacific: implications for fisheries management
Marine Biology, 2009Co-Authors: Lynne Van Herwerden, John Howard Choat, Stephen J Newman, Matthieu Leray, Grethe HillersøyAbstract:Here the population genetic structure of an ecologically and economically important coral reef fish, the coral trout Plectropomus Leopardus, is investigated in the context of contemporary and historical events. Coral trout were sampled from four regions (six locations) and partial mtDNA D-loop sequences identified six populations (Fst = 0.89209, P < 0.0001): Scott Reef and the Abrolhos Islands in west Australia; the Great Barrier Reef (GBR), represented by northern and southern GBR samples; New Caledonia and Taiwan, with Taiwan containing two genetic lineages. Furthermore, this study identified source and sink populations within and among regions. Specifically, the northern population in west Australia (Scott Reef) was identified, as the source for replenishment of the Abrolhos population, whilst New Caledonia was a source for recruitment to the GBR. Based on these insights from a single mtDNA marker, this study will facilitate the development of rational management plans for the conservation of P. Leopardus populations and therefore mitigate the risk of population declines from anthropogenic influences.
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contrasting patterns of genetic structure in two species of the coral trout plectropomus serranidae from east and west australia introgressive hybridisation or ancestral polymorphisms
Molecular Phylogenetics and Evolution, 2006Co-Authors: L Van Herwerden, John Howard Choat, Ashley J. Frisch, Christine L Dudgeon, G Carlos, Stephen J Newman, M J H Van OppenAbstract:Inter-specific genetic relationships among regional populations of two species of grouper (Plectropomus maculatus and Plectropomus Leopardus) were examined using mitochondrial and nuclear markers. mtDNA revealed contrasting regional inter-specific patterns whilst nuclear markers revealed contrasting patterns among markers, irrespective of region. In eastern Australia (EA) the species form a single mtDNA lineage, but the two species are reciprocally monophyletic in Western Australia (WA). This supports previous evidence for hybridisation between these species on the east coast. WA P. Leopardus forms a sister relationship with the EA P. Leopardus-maculatus clade while WA P. maculatus is more basal and sister to the P. Leopardus lineages, indicating mtDNA does not suffer from incomplete lineage sorting for these species. In contrast, one of three nuclear markers (locus 7-90TG) differentiated the species into two reciprocally monophyletic clades, with no evidence of hybridisation or ancestral polymorphism. The remaining two nuclear markers (2-22 and ETS-2) did not separate these two species, while distinguishing other plectropomid species, suggesting incomplete lineage sorting at these nuclear loci. These results together with coalescence analyses suggest that P. Leopardus females have hybridised historically with P. maculatus males and that P. maculatus mitochondria were displaced through introgressive hybridisation and fixation in the P. maculatus founder population on the Great Barrier Reef. The contrasting regional patterns of mtDNA structure may be attributed to Quaternary sea-level changes and shelf width differences driving different reef configurations on each coast. These reef configurations have provided opportunities for local scale interaction and reproduction among species on the narrower EA continental shelves, but not on the broader WA continental shelves.