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Plate showing distinct colour phases of (a) footballer, (b) transitional and (c) blue-spot Plectropomus laevis. Scale bars = 5 cm.
Source publication
Species in the coral trout complex Plectropomus spp. are some of the most desired and exploited in the Indo-Pacific, although data are limited for most species. Demographic parameters of blue-spot coral trout, Plectropomus laevis, were estimated on the basis of specimens collected from five regions of the Great Barrier Reef and Torres Strait, Austr...
Context in source publication
Context 1
... colour phases M. R. are related to size at sexual maturity. Smaller individuals typi- cally have the 'footballer' form characterised by a white body with black saddles, yellow fin markings and few blue spots, whereas larger individuals generally display the 'blue-spot' form with a dark brown or red body covered with distinctive large blue spots (Fig. 2). The two colour phases generally are distinct, but transitional individuals have been observed (Davies et al. 2006). This colour dimorphism is peculiar to P. laevis within the coral trout complex. Other members of the coral trout complex dis- play depth-related colour variation, from dark olive in shallow water to crimson red in deeper ...
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Citations
... The spawning patterns found in this study indicate P. maculatus contrasts with other reef fishes with restricted summer recruitment periods [1,10,22,56]. They also contrast with courtship and aggregating behaviours, spawning observations, recruitment observations and histological studies of other Plectropomus spp. on the GBR, which have been documented around new moon phases in spring and summer [36,[57][58][59][60][61][62]. However, all studies except those of Samoilys [36] and Heupel et al. [62] were restricted to spring and summer months (September to February), suggesting winter spawning events may have been missed. ...
... They also contrast with courtship and aggregating behaviours, spawning observations, recruitment observations and histological studies of other Plectropomus spp. on the GBR, which have been documented around new moon phases in spring and summer [36,[57][58][59][60][61][62]. However, all studies except those of Samoilys [36] and Heupel et al. [62] were restricted to spring and summer months (September to February), suggesting winter spawning events may have been missed. While P. leopardus and P. laevis both exhibit clear seasonal spawning in late spring and early summer on the central and northern GBR [36,62], both studies also indicate some spawning activity during other times of year, which support our findings. ...
... However, all studies except those of Samoilys [36] and Heupel et al. [62] were restricted to spring and summer months (September to February), suggesting winter spawning events may have been missed. While P. leopardus and P. laevis both exhibit clear seasonal spawning in late spring and early summer on the central and northern GBR [36,62], both studies also indicate some spawning activity during other times of year, which support our findings. While our results were not corroborated with histological assessments of seasonal gonad development, parentage studies have confirmed that the large majority of juvenile P. maculatus that successfully recruit to the Keppel Islands originate from local reefs [15,63], and are therefore representative of spawning activity throughout the year. ...
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.
... Considering the 50% maturity of the species is at 43.3 cm FL (Ebisawa, 2013), the size regulation at 40 or 45 cm FL seems to be effective for fisheries management. The species P. laevis also grows much larger (up to ca. 18 kg in this study) and shows faster growth than P. leopardus (Heupel et al., 2010), and a similar size regulation might be effective. On the other hand, standardized price slightly decreased larger than 4.0 kg, because of handling difficulty as reported in large fish species (Shimose et al., 2018(Shimose et al., , 2019. ...
Body color of the coralgroupers (Serranidae, Plectropomus) is known to vary from red to brown and dark to pale, with a vivid red color is thought to be preferred in fish markets of East Asia. This study revealed quantitative effects of the body color of coralgroupers on the market value at fish market in Okinawa, Japan. Results showed that bid price of six color grades of P. leopardus are significantly different, and normal- to dark-red individuals were sold at higher auction prices than light-brown and light-red individuals. Results also showed that unit price per kg of coralgroupers increased up to 1.5 kg body weight but slightly decreased for fish larger than 4 kg. Increase of fish supply in the market greatly reduced the bid price of the coralgroupers, and condition factor (index of fatness for individual fish) influenced the bid price of individual fish. These results indicate that an effective fisheries management strategy could be available if the optimal size and color individuals were harvested for days/weeks when a shortage of wild fish catch occurred.
... Our results also show that P. laevis have slower growth rates, are longer lived and have lower total mortality rates than any other species of coral grouper, consistent with previous studies where growth has been characterized (Frisch et al., 2016;Grandcourt, 2002;Heupel et al., 2010). These life history traits are likely to translate to slower population turnover rates and make P. laevis inherently more vulnerable to fishing and slower to recover relative to other species of coral grouper. ...
... given that historical collections were made on hook and line (Heupel et al., 2010;Mapstone et al., 2004) and contemporary collections were largely made using spear guns. It is possible that the 80 lbs hand-lines used may not have been capable of landing exceptionally large fish, thereby underestimating mean maximum lengths of P. laevis in the GBRMP. ...
... Contrasting patterns of growth have also been measured for populations of coral grouper in other locations, including P. leopardus from the GBR (Ferreira & Russ, 1994) and Japan (Ebisawa, 2013), P. laevis from the Seychelles (Grandcourt, 2002) and P. laevis from the GBR (Heupel et al., 2010), with estimates of growth rate and asymptotic length being larger than our estimates in all cases. However, we emphasize caution when comparing growth parameters among models when sizes at settlement were not constrained to a common value. ...
Understanding the spatial and environmental variation in demographic processes of fisheries target species, such as coral grouper (Genus: Plectropomus), is important for establishing effective management and conservation strategies. Herein we compare the demography of Plectropomus leopardus and P. laevis between Australia's Great Barrier Reef Marine Park (GBRMP), which has been subject to sustained and extensive fishing pressure, and the oceanic atolls of Australia's Coral Sea Marine Park (CSMP), where there is very limited fishing for reef fishes. Coral grouper length‐at‐age data from contemporary and historical otolith collections across 9.4 degrees of latitude showed little difference in lifetime growth between GBRMP and CSMP regions. Plectropomus laevis populations in GBRMP reefs had significantly higher rates of total mortality than populations in the CSMP. Mean maximum lengths and mean maximum ages of P. laevis were also smaller in the GBRMP than in the CSMP, even when considering populations sampled within GBRMP no‐take marine reserves (NTMRs). Plectropomus leopardus, individuals were on average smaller on fished reefs than NTMRs in the GBRMP, but all other aspects of demography were broadly similar between regions despite the negligible levels of fishing pressure in the CSMP. Similarities between regions in growth profiles and length‐at‐age comparisons of P. laevis and P. leopardus suggest that the environmental differences between the CSMP and the GBRMP may not have significant impacts on lifetime growth. Our results show that fishing may have influenced the demography of coral grouper on the GBR, particularly for the slower growing and longer lived species, P. laevis.
... It consists of seven species, of 107 which the following three are commonly found in the GBR: P. leopardus, 108 P. maculatus and P. laevis. Additionally, P. laevis undergoes a shift from footballer (FBT) to blue-spot (BST) colour phase 109 that may be linked to behaviour, growth and maturity (Heupel et al. 2010). These closely related Plectropomus species 110 occur sympatrically in tropical coral reefs (Matley et al. 2016(Matley et al. , 2017a(Matley et al. , 2017b). ...
Tropical reefs are highly diverse ecosystems, and reliable biomonitoring, through diet metabarcoding, is needed to understand present and future trophic relationships in this changing habitat. Several studies have assessed the reliability and effectiveness of single molecular markers; however, a cross-marker validation has rarely been performed. This study identified crucial properties for 12S rDNA, 16S rDNA and COI metabarcoding in tropical-reef piscivores (Plectropomus spp.). In addition, three new versatile primer sets for 16S were designed in silico for metabarcoding of reef fish. Results showed that COI was overall better at recovering true diversity because of a well-supported database. Second, optimal 16S amplicon sizes ranged between 160 and 440 base pairs for full diversity recovery, with increased species detection for the 270-base pairs region. Finally, blocking of predator-specific COI sequences was not equally effective in all host species, potentially introducing bias when diet compositions are directly compared. In conclusion, this novel study showed that marker success for prey identification is highly dependent on the reference database, taxonomic scope, DNA quality, amplicon length and sequencing platform. Results suggest that COI, complemented with 16S, yields the best outcome for diet metabarcoding in reef piscivores. Findings in this paper are relevant to other piscivores and other metabarcoding applications.
... Knowledge of resource-use overlap between sympatric species is important from an ecological context but also has significant bearing on management and conservation of exploited species. Closely related species are often treated as single stocks due to similar morphology and distribution (Heupel et al. 2010). Grouping sympatric species for management purposes can be problematic because life history traits and population dynamics are often different . ...
... length) than the more abundant and widespread P. leopardus (matures at 2 to 3 yr; ~60 cm max. length) (Ferreira 1995, Heupel et al. 2010. Additionally, P. laevis undergoes a dramatic colour transition from footballer (white/yellow/ black) to blue-spot (dark with large blue spots) phase upon reaching ~30 cm (~1:1 footballer:blue-spot at 50 cm; Heupel et al. 2010). ...
... length) (Ferreira 1995, Heupel et al. 2010. Additionally, P. laevis undergoes a dramatic colour transition from footballer (white/yellow/ black) to blue-spot (dark with large blue spots) phase upon reaching ~30 cm (~1:1 footballer:blue-spot at 50 cm; Heupel et al. 2010). Both species overlap in distribution, but little is known about resource and habitat selection, particularly for P. laevis, which remains poorly studied. ...
Prey selection can influence interactions among species, the composition and abundance of prey, and ultimately the movement of energy within the ecosystem. Different species of the exploited coral trout (Plectropomus spp.) often co-occur in reef environments, but their foraging behaviour and ecological niches are largely unknown. To explore niche overlap and resource use of sympatric adult coral trout, stable isotopes (δ13C and δ15N) were quantified for three tissues (muscle, red blood cells, plasma) collected between August 2013 and February 2014 from P. leopardus (n = 117) and P. laevis (n = 36) at four reefs in eastern Australia. Bayesian standard ellipses were used to show that prey selection of P. leopardus varied considerably from P. laevis, particularly the blue-spot colour phase. Size of adult individuals had little influence on δ13C and δ15N values for P. leopardus and both footballer and blue-spot colour phases of P. laevis. Spatio-temporal comparisons of P. leopardus trophic positions, made by adjusting baseline algae and planktonic δ15N at each reef and sampling period, demonstrated that trophic positions varied in time and space, and warrants further investigations. This study highlights that sympatric species of coral trout have distinct ecological roles and will likely react differently to environmental disturbances and/or changes in habitat/prey composition.
... Due to its widespread abundance and value overseas, scientific research, stock assessments, and commercial logbooks have concentrated on P. leopardus or grouped all species together for simplicity despite biological differences. For example, P. laevis, the second most abundant 'coral trout' species at mid-shelf and offshore reefs (Ayling and Choat 2008), grows larger (~100 cm max length) and matures earlier (~1 year) than P. leopardus (matures at 2-3 years; ~60 cm max length) (Ferreira 1995;Heupel et al. 2010), yet no prior study has specifically investigated resource use or movement patterns of P. laevis. ...
... Although P. leopardus stocks appear to be healthy (Leigh et al. 2014), there is growing concern that over-exploitation (Little et al. 2005;McLean et al. 2011), climate change (Johansen et al. 2015), and extreme weather events (Tobin et al. 2010) will adversely affect sustainability. Similarly, P. laevis is currently listed as 'Vulnerable' on the IUCN Red List and without sufficient data, effective management strategies are not possible (Heupel et al. 2010). Considering the relative importance of the 'coral trout' fishery and concerns about its future, there is a large gap in knowledge relating to interactions between sympatric species and potential ecological and humanassociated impacts. ...
... depth sensors followed tidal influences alone), the affected portion of data was removed. Logistic regression (binomial family with logit function) tested whether the inclusion Table 1 Sampling summary of P. laevis and P. leopardus including mean (±SE) size, days at liberty, and the number of days detected (numbers in brackets the range) for those individuals that were analysed Only individuals that were detected ≥25 times and for ≥15 days were analysed a Of the three individuals not analysed here, one was not included because it was mainly detected on the reef flat b These two individuals were not used in inter-reef comparisons or presence measurements c Of the 22 individuals not analysed here, two were not included because they were mainly detected on the reef flat d Lodestone individuals were not included in inter-reef comparisons e The size of maturity of P. leopardus and P. laevis is ~300 mm (Ferreira 1995;Heupel et al. 2010 (presence) or removal (absence) of individuals from data analysis was influenced by release distance from a receiver, the size of fish, reef, or release location (i.e. each reef divided into four sections, each containing two receivers: north-east, south-east, north-west, south-west). Validated detections were grouped into 2-h intervals to reduce effects of autocorrelation between consecutive time periods and to estimate individual locations using a position averaging algorithm (see below). ...
Understanding spatial distribution and temporal variation in movement patterns of closely related species is relevant for deciphering how resources are selected and whether interactions between species affect resource use patterns. The horizontal space use and vertical space use of two exploited reef fish, Plectropomus leopardus and P. laevis (all adults), were compared at mid-shelf Helix Reef and Lodestone Reef in the Great Barrier Reef over ~3 years using passive acoustic telemetry. Both species were detected throughout the 12-month duration of transmitters (mean detection period: ~270 days) and often made deep movements to ~40 m possibly related to reproductive behaviour (spawning). Differences in space use were apparent between species, with P. laevis consistently using greater area around reefs throughout the year. Overall, depth use patterns were similar between species; however, when daily detections were grouped in 2-h periods, P. laevis remained shallower and had greater variation in depth
... A total of 11 publications on 4 plectropomids were used (Currey et al., 2010, Ebisawa, 2013Ferreira and Russ, 1992;Grandcourt, 2005;Heupel et al., 2010b;Loubens, 1978Loubens, , 1980aRuss et al., 1998;Rhodes et al., 2013;Williams et al., 2008) to develop 8 estimates of L m /L ∞ and 14 estimates of M/k (Table A4). Five published studies on 2 Variola species (V. ...
... However for both sectors coral trout made up 66% of the total harvest by weight probably due to the TIB sector taking significantly more blue spot coral trout (Plectropomus laevis) than the TVH sector (Williams et al. 2008a). P. laevis are the largest of the coral trout species (Heupel et al. 2010). For both sectors P. leopardus is the major species harvested at around 80% of all coral trout. ...
Climate change is considered to be a major environmental threat and there is a national priority to better establish the likely effects of climate change on Australia’s fisheries. Positive and negative impacts of climate change on marine fisheries are already being observed in tropical regions, including the GBR and Pacific. In the Torres Strait region, fisheries impacts are likely to manifest in changes to species stock structure, phenology, distribution shifts, and indirectly through habitat changes. Torres Strait Islanders have a long history of association with their marine resources and fisheries species are of significant cultural, social and economic importance. Any impacts of climate change on marine fisheries stocks and the habitats that support them will affect Torres Strait communities and potentially include changes in the accessibility of target species, changes in the reliability of food supply, and reduced sustainability of fisheries. Therefore, there is an imperative for Traditional Owners, Torres Strait communities, fishers and managers to understand what these impacts are likely to be, which fisheries are expected to be most vulnerable, and to use this information to prepare for negative effects and capitalize on opportunities.We assessed the relative vulnerability of Torres Strait fisheries by conducting a vulnerability assessment on 15 key fishery species. We applied a structured semi-quantitative approach for the vulnerability assessments based on a widely-adopted framework that includes the elements of Exposure, Sensitivity and Adaptive Capacity proposed by the Intergovernmental Panel on Climate Change and United Nations Framework Convention on Climate Change. The assessments were informed by comprehensive literature reviews of Torres Strait climate (observed and projected), key fishery habitats and their vulnerability to climate change, and species reviews for 10 fishery groups that covered fishery characteristics, species life cycles and sensitivity to environmental changes. The assessments were further informed by results of interviews with Torres Strait Islanders.
The results of the vulnerability assessments identified species with high, medium and low relative vulnerability to climate change. The species identified as having the highest relative vulnerability were: black teatfish, black-lipped pearl oyster, dugong, and trochus. When vulnerability was combined with the level of importance of each species to fisheries in Torres Strait (using a measure of cultural and economic value), a priority list of five species was identified for future action by management. These species were: dugong, turtle, tropical rock lobster, trochus and gold-lipped pearl oyster.
This project concludes that there are a number of environmental changes that will be experienced in the Torres Strait by 2030, including habitat impacts that will have flow-on effects on a number of key fisheries. The main drivers are likely to be increases in sea surface temperature, increased severity of storms, and habitat changes particularly to coral reefs and seagrass meadows. The report also provides a range of recommendations on future actions and research that should arise from this project. These are grouped into three themes: (1) improving assessment accuracy, (2) extension of results to communities and decision-makers, and (3) research to address key knowledge gaps.
... Among epinephelids, a wide range of sexual patterns has been identified (Sadovy de Mitcheson & Liu, 2008). Studies of sexual pattern in plectropomids have all reported protogyny (mature female to mature male sex change) (Ferreira, 1993(Ferreira, , 1995Adams, 2003), together with rapid growth and short life spans (Ferreira & Russ, 1992, 1994Heupel et al ., 2010). Sexual pattern in P . ...
... S E X UA L PAT T E R N Epinephelids display a variety of sexual patterns (Sadovy de Mitcheson & Liu, 2008), with all plectropomids examined to date demonstrating protogyny: P . maculatus (Ferreira, 1993;1995;Adams, 2003;Williams et al ., 2008b), leopard coralgrouper Plectropomus leopardus (Lacépède 1802) (Ferreira, 1995;Williams et al ., 2008b) and blacksaddled coralgrouper Plectropomus laevis (Lacépède 1801) (Heupel et al ., 2010). The only previous study to examine sexual pattern for P . ...
... In Pohnpei, P . areolatus displays fast growth, early maturity and a life span and mortality schedule similar to other plectropomids (Ferreira & Russ, 1992, 1994Adams et al ., 2000;Williams et al ., 2008b;Heupel et al ., 2010). Growth patterns were sex specific, with male mean maximum size exceeding that of females, and highly asymptotic, with 90% of the L ∞ achieved by age 3 years. ...
The squaretail coralgrouper Plectropomus areolatus was identified as a fast-growing, early maturing and relatively short-lived aggregation-spawning epinephelid. Examinations of sectioned otoliths found females and males first maturing at 2 and 3 years, respectively, suggesting protogynous hermaphroditism; however, no transitionals were observed in samples. Age distribution for the two sexes was similar and both were represented in the oldest age class; however, significant sex-specific differences in size-at-age were identified. Both sexes fully recruit into the fishery at age 4 years and reach 90% of asymptotic length by age 3 years. Underwater visual assessments, combined with the gonado-somatic indices, revealed a 5 month reproductive season, with interannual variability observed in the month of highest density within the spawning aggregation. Catch restrictions on adults during spawning times and at reproductive sites, combined with gear-based management and enhanced enforcement, are recommended to maintain spawning stocks. Based on the available evidence, the sexual pattern for this species is unresolved.
... However for both sectors coral trout made up 66% of the total harvest by weight probably due to the TIB sector taking significantly more blue spot coral trout (Plectropomus laevis) than the TVH sector (Williams et al. 2008a). P. laevis are the largest of the coral trout species (Heupel et al. 2010). For both sectors P. leopardus is the major species harvested at around 80% of all coral trout. ...
Climate change is considered to be a major environmental threat and there is a national priority to better establish the likely effects of climate change on Australia’s fisheries. Positive and negative impacts of climate change on marine fisheries are already being observed in tropical regions, including the GBR and Pacific. In the Torres Strait region, fisheries impacts are likely to manifest in changes to species stock structure, phenology, distribution shifts, and indirectly through habitat changes. Torres Strait Islanders have a long history of association with their marine resources and fisheries species are of significant cultural, social and economic importance. Any impacts of climate change on marine fisheries stocks and the habitats that support them will affect Torres Strait communities and potentially include changes in the accessibility of target species, changes in the reliability of food supply, and reduced sustainability of fisheries. Therefore, there is an imperative for Traditional Owners, Torres Strait communities, fishers and managers to understand what these impacts are likely to be, which fisheries are expected to be most vulnerable, and to use this information to prepare for negative effects and capitalize on opportunities.
We assessed the relative vulnerability of Torres Strait fisheries by conducting a vulnerability assessment on 15 key fishery species. We applied a structured semi-quantitative approach for the vulnerability assessments based on a widely-adopted framework that includes the elements of Exposure, Sensitivity and Adaptive Capacity proposed by the Intergovernmental Panel on Climate Change and United Nations Framework Convention on Climate Change. The assessments were informed by comprehensive literature reviews of Torres Strait climate (observed and projected), key fishery habitats and their vulnerability to climate change, and species reviews for 10 fishery groups that covered fishery characteristics, species life cycles and sensitivity to environmental changes. The assessments were further informed by results of interviews with Torres Strait Islanders.
The results of the vulnerability assessments identified species with high, medium and low relative vulnerability to climate change. The species identified as having the highest relative vulnerability were: black teatfish, black-lipped pearl oyster, dugong, and trochus. When vulnerability was combined with the level of importance of each species to fisheries in Torres Strait (using a measure of cultural and economic value), a priority list of five species was identified for future action by management. These species were: dugong, turtle, tropical rock lobster, trochus and gold-lipped pearl oyster.
This project concludes that there are a number of environmental changes that will be experienced in the Torres Strait by 2030, including habitat impacts that will have flow-on effects on a number of key fisheries. The main drivers are likely to be increases in sea surface temperature, increased severity of storms, and habitat changes particularly to coral reefs and seagrass meadows. The report also provides a range of recommendations on future actions and research that should arise from this project. These are grouped into three themes: (1) improving assessment accuracy, (2) extension of results to communities and decision-makers, and (3) research to address key knowledge gaps.
The relatively healthy condition of most fisheries in the Torres Strait will aid in the success of any adaptation options implemented. Adaptations that focus on sustainable management of stocks, habitat preservation (coral reefs and seagrass) and diversification of fisheries species hold the most promise for fisheries under climate change. Strong local governance is also important in an uncertain and changing future.
