Geographic variation in the sex ratio, sex specific size, and age structure of Plectropomus leopardus (Serranidae) between reefs open and closed to fishing on the Great Barrier Reef

2000 ◽  
Vol 57 (7) ◽  
pp. 1448-1458 ◽  
Author(s):  
S Adams ◽  
B D Mapstone ◽  
G R Russ ◽  
C R Davies
Keyword(s):  
Sex Ratio ◽  
Great Barrier Reef ◽  
Age Structure ◽  
Spatial Scales ◽  
Geographic Region ◽  
Minimum Size ◽  
Barrier Reef ◽  
Reproductive Parameters ◽  
Size And Age Structure ◽  
Plectropomus Leopardus

Variation in reproductive parameters of Plectropomus leopardus populations between coral reefs open and closed to fishing was examined in two geographic regions (off Townsville (19°S) and in the Swains (22°S)) of the Great Barrier Reef, Australia. The reproductive parameters that were examined included the operational (reproductive) sex ratio and size and age structure of mature females, sex-changing individuals (transitionals), and mature males. There was a greater proportion of males above the minimum size and age of harvest on reefs closed to fishing for 8-10 years than on reefs open to fishing, although the effect varied with geographic region. Nevertheless, neither the sex ratio, mean age, nor mean size of males or transitionals varied significantly with reef closure status. Females, however, were significantly older and larger on closed than on open reefs in both regions. Marked regional variations in the sex ratio and average age of transitionals were found independent of reef closure status, suggesting regional variation in reproductive strategies. Controlled manipulations, inclusion of broad spatial scales, and detailed studies of intra- and inter-specific variation in serranid reproductive biology are necessary to resolve such complexities in the responses of protogynous serranids to fishing pressure and management strategies.

A new species of Stephanostomum Looss, 1899 (Digenea, Acanthocolpidae) with a bizarre oral sucker: S. adlardi sp. nov. from the common coral trout Plectropomus leopardus (Lacepède, 1802) (Perciformes, Serranidae) from Lizard Island, Great Barrier Reef

2007 ◽  
Vol 52 (3) ◽  
Author(s):  
Rodney Bray ◽  
Thomas Cribb ◽  
Andrea Waeschenbach ◽  
D. Littlewood
Keyword(s):  
New Species ◽  
Great Barrier Reef ◽  
Oral Sucker ◽  
Ribosomal Rna ◽  
Barrier Reef ◽  
Coral Trout ◽  
Lizard Island ◽  
The Common ◽  
Plectropomus Leopardus ◽  
A New Species

AbstractA new species of Acanthocolpidae, Stephanostomum adlardi is described from the serranid Plectropomus leopardus from Lizard Island in the northern Great Barrier Reef. It differs from all previously described acanthocolpids in the structure of the oral sucker which is extended into dorsal and ventral lobes each bearing a row of spines. A phylogenetic tree estimated from combined nuclear small and partial large ribosomal RNA gene sequences shows that, despite the unusual oral sucker structure, the species is a true member of the genus Stephanostomum. The molecular results also suggest that Monostephanostomum nolani is derived from within Stephanostomum.

Population estimates and size structure of Plectropomus leopardus (Pisces : Serranidae) in relation to no-fishing zones: mark-release-resighting and underwater visual census

2000 ◽  
Vol 51 (3) ◽  
pp. 221 ◽  
Author(s):  
D. C. Zeller ◽  
G. R. Russ
Keyword(s):  
Great Barrier Reef ◽  
Population Size ◽  
Size Structure ◽  
Barrier Reef ◽  
Visual Census ◽  
Underwater Visual Census ◽  
Coral Trout ◽  
Population Size Estimates ◽  
Lizard Island ◽  
Plectropomus Leopardus

A mark–release–resighting (MRR) technique was used to estimate population size of the coral trout, Plectropomus leopardus, on coral reefs fringing Lizard Island, Great Barrier Reef, Australia. Fish were captured by hook-and-line fishing, and marked with individual freeze-brand numbers in August 1995. An underwater visual census (UVC) technique was used during September and October 1995 both for resighting of marked fish and to make an independent estimate of fish density and thus population size. The study area was 750 966 m2 . The UVC sampled 154 000 m2 (20.5%) of this area. Six different methods of analysis of MRR gave similar population size estimates (e.g. Petersen 12 873; 95% CI 9989–15 754) extrapolated to the 4.5 million-m2 reef area from datum to 20-m depth around Lizard Island. UVC gave a population size estimate (24 182; 95% CI 21 860–26 504) twice that of MRR. The lower estimate derived from MRR may be the result of tag-induced mortality, or of the relative difficulty in discriminating between marked and unmarked trout by UVC. This is only the second estimate of population size of coral trout on an area of the Great Barrier Reef.

scholarly journals Long-term shifts in the colony size structure of coral populations along the Great Barrier Reef

2020 ◽  
Vol 287 (1936) ◽  
pp. 20201432
Author(s):  
Andreas Dietzel ◽  
Michael Bode ◽  
Sean R. Connolly ◽  
Terry P. Hughes
Keyword(s):  
Great Barrier Reef ◽  
Colony Size ◽  
Size Structure ◽  
Coral Cover ◽  
Spatial Scales ◽  
Reproductive Capacity ◽  
Barrier Reef ◽  
Size Frequency Distribution ◽  
Coral Colony ◽  
Recovery Potential

The age or size structure of a population has a marked influence on its demography and reproductive capacity. While declines in coral cover are well documented, concomitant shifts in the size-frequency distribution of coral colonies are rarely measured at large spatial scales. Here, we document major shifts in the colony size structure of coral populations along the 2300 km length of the Great Barrier Reef relative to historical baselines (1995/1996). Coral colony abundances on reef crests and slopes have declined sharply across all colony size classes and in all coral taxa compared to historical baselines. Declines were particularly pronounced in the northern and central regions of the Great Barrier Reef, following mass coral bleaching in 2016 and 2017. The relative abundances of large colonies remained relatively stable, but this apparent stability masks steep declines in absolute abundance. The potential for recovery of older fecund corals is uncertain given the increasing frequency and intensity of disturbance events. The systematic decline in smaller colonies across regions, habitats and taxa, suggests that a decline in recruitment has further eroded the recovery potential and resilience of coral populations.

scholarly journals Comparative demography of commercially important species of coral grouper, Plectropomus leopardus and P. laevis , from Australia's great barrier reef and Coral Sea marine parks

2020 ◽  
Vol 97 (4) ◽  
pp. 1165-1176
Author(s):  
Samuel D. Payet ◽  
Jake R. Lowe ◽  
Bruce D. Mapstone ◽  
Morgan S. Pratchett ◽  
Tane H. Sinclair‐Taylor ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Barrier Reef ◽  
Important Species ◽  
Coral Sea ◽  
Comparative Demography ◽  
Commercially Important ◽  
Plectropomus Leopardus

Response by Plectropomus-Leopardus and Other Serranid Fishes to Pearsonellum-Corventum (Digenea, Sanguinicolidae), Including Melanomacrophage Centers in the Heart

1989 ◽  
Vol 37 (1) ◽  
pp. 129 ◽  
Author(s):  
RM Overstreet ◽  
J Thulin
Keyword(s):  
Foreign Body ◽  
Gulf Of Mexico ◽  
Great Barrier Reef ◽  
Foreign Bodies ◽  
Body Cavity ◽  
The Body ◽  
Barrier Reef ◽  
Geographic Regions ◽  
Plectropomus Leopardus ◽  
Normal Feature

Adults of the blood fluke Pearsonellum corventum in the heart of Plectropomus leopardus from the Great Barrier Reef evoked a detectable response, but the continual production of their eggs induced a more significant response, including an abundance of melanomacrophage centres (MMCS) and granuloma formation in the ventricle as well as in other visceral organs. MMCs have not been recognised previously as a component of the ventricular spongiosis layer in fishes, but they were a normal feature of the infected and perhaps all P. leopardus as well as certain other serranids. Moreover, at least P. leopardus and certain nonserranid fishes from the Gulf of Mexico contain an abundance of free macrophages among ventricular myocardial and endocardia1 tissues. Because of those MMCS and free macrophages in P. leopardus, as well as an apparently independent extensive response involving pigmented fibrotic encapsulation of foreign bodies in the body cavity in that and other serranids from the Gulf of Mexico and Red Sea, P. leopardus and probably several other serranids should provide especially valuable models to assess macrophages and nonspecific pigmented foreign body responses. Sections in the heart of two serranids from other geographic regions exhibited what appeared to be different sanguinicolid eggs, and those fishes responded differently to P. leopardus.

Benthic community composition influences within-habitat variation in macroalgal browsing on the Great Barrier Reef

2010 ◽  
Vol 61 (9) ◽  
pp. 999 ◽  
Author(s):  
C. Cvitanovic ◽  
A. S. Hoey
Keyword(s):  
Coral Reefs ◽  
Great Barrier Reef ◽  
Benthic Community ◽  
Spatial Scales ◽  
Structural Complexity ◽  
Barrier Reef ◽  
Removal Rates ◽  
Ecological Processes ◽  
Habitat Variation ◽  
Benthic Composition

The removal of macroalgae by herbivores is fundamental to the long-term persistence of coral reefs. Variation in macroalgal browsing has been documented across a range of spatial scales on coral reefs; however, few studies have examined the factors that influence within-habitat rates of herbivory. The aim of the present study was to quantify herbivory on two species of Sargassum across three bays on an inshore island in the central Great Barrier Reef (GBR), and to determine whether these removal rates were related to the benthic composition or herbivorous fish communities. Removal rates of Sargassum differed significantly among bays, with removal rates in the southern bay (66.9–83.0% per 3 h) being approximately double that of the two other bays (29.2–38.5% per 3 h). The removal rates displayed a direct relationship with the benthic community structure, in particular the cover of macroalgae and live plate corals. Although it is difficult to determine whether these relationships are related to the availability of food resources or the structural complexity of the substratum, they highlight the potential influence of benthic composition on ecological processes. Quantifying and understanding the drivers of herbivory across a range of spatial scales is essential to the future management of coral reefs.

Demography, fishery yield and potential management strategies of painted spiny lobster (Panulirus versicolor) at Northwest Island, Great Barrier Reef, Australia

2012 ◽  
Vol 63 (5) ◽  
pp. 387
Author(s):  
Ashley J. Frisch ◽  
Jean-Paul A. Hobbs
Keyword(s):  
Great Barrier Reef ◽  
Fishery Management ◽  
Spiny Lobster ◽  
Management Strategies ◽  
Minimum Size ◽  
Demographic Parameters ◽  
Barrier Reef ◽  
Minimal Impact ◽  
Demographic Processes ◽  
Yield Per Recruit

Quantification of demographic parameters is important for understanding how populations interact with their environment and for developing sustainable harvest strategies. Our aims were to quantify demographic parameters and yield of painted spiny lobster (Panulirus versicolor) at Northwest Island, Great Barrier Reef and review fishery management regulations in view of the findings. Using catch-curve analysis and an intensive mark–recapture program, the local lobster population was found to be sparsely distributed (~1.3 ha–1), with low rates of natural mortality (0.25–0.28 year–1) and immigration (0.05 ha–1 year–1). Under current management regulations (no minimum size limit; MSL), yield-per-recruit peaked at 0.38 kg when fishing mortality was 0.4 year–1. Implementation of a 100-mm (carapace length) MSL is recommended because it provides the best compromise between yield and stock size and has minimal impact on existing fishing practices. Revocation of the prohibition on possessing egg-bearing females is also recommended because it would reduce wastage of lobsters that are inadvertently killed by spear-fishers and because there appears to be little chance of localised recruitment overfishing. This study provides the first estimate of mortality rate for P. versicolor and highlights the importance of this parameter for understanding demographic processes and optimising management regulations.

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