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Many predatory marine fishes undergo ontogenetic diet and habitat shifts as they grow. Most fishery datasets, such as catch records, length frequencies, and stomach contents, create a series of snapshots, with each captured fish representing a single timepoint during the lifespan. Chemical archives, such as eye lenses, preserve information regarding several life stages for each individual. By combining these disparate datasets, conclusions are strengthened through weight of evidence. We combined a novel archive, δ13C and δ15N bulk values in sequential eye-lens laminae, with fishery-independent catch records and stomach contents for red grouper Epinephelus morio (Valenciennes 1828) from the eastern Gulf of Mexico, USA. Eye-lens core isotope values suggest that successful individuals spend their larval period on the mid-to-outer continental shelf and locations do not vary substantially year-to-year. Profiles of δ15N values indicate that trophic position increases with size following a logarithmic growth model, while stomach contents indicate a simultaneous increase in fish proportion in the diet. Stomach contents and δ13C values together suggest that most red grouper move to nearshore waters at settlement, spend several months in shallow water with heavy benthic diet dependence, then slowly cross the continental shelf toward deeper water as they mature. With this work, we demonstrate that eye-lens isotope value profiles can enhance fisheries datasets and may provide a method of recreating diet and movement histories for species without long-term biological information. [ABSTRACT FROM AUTHOR]

Ecosystem-based fisheries-management (EBFM) is increasingly used in the United States (U.S.), including in the Gulf of Mexico (GOM). Producing distribution maps for marine organisms is a critical step in the implementation of EBFM. In particular, distribution maps are important inputs for many spatially-explicit ecosystem models, such as OSMOSE models, as well as for biophysical models used to predict annual recruitment anomalies due to oceanographic factors. In this study, we applied a recently proposed statistical modelling framework to produce distribution maps for: (i) younger juveniles (ages 0-1) of red snapper (Lutjanus campechanus), red grouper (Epinephelus morio), and gag (Mycteroperca microlepis), so as to be able to define the potential larval settlement areas of the three species in a biophysical model; and (ii) the functional groups and life stages represented in the OSMOSE model of the West Florida Shelf ("OSMOSE-WFS"). This statistical modelling framework consists of: (i) compiling a large database blending all of the encounter/non-encounter data of the GOM collected by the fisheries-independent and fisheries-dependent surveys using random sampling schemes, referred to as the "comprehensive survey database;" (ii) employing the comprehensive survey database to fit spatio-temporal binomial generalized linear mixed models (GLMMs) that integrate the confounding effects of survey and year; and (iii) using the predictions of the fitted spatio-temporal binomial GLMMs to generate distribution maps. This large endeavour allowed us to produce distribution maps for younger juveniles of red snapper, red grouper and gag and nearly all of the other functional groups and life stages represented in OSMOSE-WFS, at different seasons. Using Pearson residuals, the probabilities of encounter predicted by all spatio-temporal binomial GLMMs were demonstrated to be reasonable. Moreover, the results obtained for younger juvenile fish concur with the literature, provide additional insights into the spatial distribution patterns of these life stages, and highlight important future research avenues. [ABSTRACT FROM AUTHOR]

Organisms that either directly or indirectly modify the availability of resources can have profound effects on the structure and function of ecological communities. This holds true for organisms that enhance habitat complexity either as a function of their morphology or through mechanical activities, such as digging or burrowing. The net positive effects of engineers on local species diversity follows from activities that allow more species to live in modified habitats compared to unmodified ones. Here, we present the results of a multiyear observational study evaluating the effects of habitat modifications made by juvenile red grouper, Epinephelus morio (Valenciennes, 1828), on the fishes and motile macroinvertebrates associated with karst solution holes in Florida Bay, FL, USA. Because red grouper have multiple roles in these systems, acting as both habitat engineers and predators that consume a variety of benthic crustaceans and fishes, their influence on associated communities is complex. We found that the presence of red grouper resulted in deeper solution holes, increased abundance and richness of the associated fauna, especially among juvenile coral-reef fishes and motile invertebrates, and significant differences in the structure of faunal communities over time. These results suggest that red grouper shape unique communities, distinct from those of surrounding areas, and strongly influence the composition of communities associated with manipulated habitats. [ABSTRACT FROM AUTHOR]

The insufficiently known nematode species Philometra margolisi Moravec, Vidal-Martínez et Aguirre-Macedo, 1995 (Philometridae) is redescribed based on light and scanning electron microscopical (SEM) examinations of specimens collected from the gonad of the type host, the red grouper Epinephelus morio (Valenciennes) (Serranidae, Perciformes), in the northern Gulf of Mexico off Florida, USA. Also, new prevalence data for females of P. margolisi were derived from 188 fish, and a subset of these (n = 38) were used to determine prevalence and intensity of male nematodes. The male of this species was studied with SEM for the first time, which revealed some new, taxonomically important morphological features. The male posterior end had a V-shaped caudal mound, four pairs of minute adanal papillae, a pair of large papillae located posterior to the cloacal aperture and a pair of very small phasmids. The distal end of the gubernaculum is unique among all gonad-infecting species of Philometra parasitizing serranids in that its ventral surface is flat, smooth, without the usual two longitudinal grooves; the dorsal lamellate structures on the gubernaculum are also different in this species. In contrast to data in the original species description, the body length of gravid females of P. margolisi was 132-280 mm. Overall prevalence for male nematodes (76.3%) was much higher than for females (15.4%), and female nematode prevalence was higher in samples collected during host spawing season than out of season (27.1% and 3.3%, respectively). [ABSTRACT FROM AUTHOR]

Copyright of Neotropical Ichthyology is the property of Neotropical Ichthyology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Invasive lionfish ( Pterois volitans/miles complex) now permeate the entire tropical western Atlantic, Caribbean Sea, and Gulf of Mexico, but lionfish abundance has been measured only in select locations in the field. Despite its rapid range expansion, a comprehensive meta-population analysis of lionfish 'sources' and 'sinks' and consequentially the invader's potential abundance and impacts on economically important, sympatric reef fishes have not been assessed. These data are urgently needed to spatially direct control efforts and to plan for and perhaps mitigate lionfish-caused damage. Here, we use a biophysical computer model to: (1) forecast larval lionfish sources and sinks that are also delineated as low to high lionfish 'density zones' throughout their invaded range, and (2) assess the potential vulnerability of five grouper and snapper species- Epinephelus morio, Mycteroperca microlepis, Epinephelus flavolimbatus, Lutjanus campechanus, and Rhomboplites aurorubens-to lionfish within these density zones in the Gulf of Mexico. Our results suggest that the west Florida shelf and nearshore waters of Texas, USA, and Guyana, South America, function both as lionfish sources and sinks and should be a high priority for targeted lionfish control. Furthermore, of the five groupers and snappers studied, the high fishery value E. morio (red grouper) is the Gulf of Mexico species most at risk from lionfish. Lacking a comprehensive lionfish control policy, these risk exposure data inform managers where removals should be focused and demonstrate the risk to five sympatric native groupers and snappers in the Gulf of Mexico that may be susceptible to dense lionfish aggregations, should control efforts fail. [ABSTRACT FROM AUTHOR]

Marine connectivity over seascapes enables the persistence of metapopulations and is often regulated in part by an organism's pelagic larval duration (PLD), fecundity, mortality, and ocean conditions. The Campeche Bank (CB) in the southern Gulf of Mexico flanks the strong-flowing Loop Current and is important ecologically and economically in the context of mesoscale connectivity to the Gulf. Here we use a biophysical model to examine connectivity between the CB and the northeastern Gulf (NEGOM) of simulated populations of lionfish ( Pterois volitans/ miles), red grouper ( Epinephelus morio), and a generic marine organism. Our purpose was to assess longitudinal connectivity across the CB to the NEGOM and also to quantify this connectivity over a range of PLDs and organism fecundities. From this work, we find that portions of the northeastern perimeter of the CB in water depths between 50 and 300 m are the majority sources of lionfish and red grouper recruits to the NEGOM. This finding is important as deep waters on the bank are often heavily targeted by commercial fishers and are also beyond the reach of present lionfish control regimes. We also demonstrate that buoyant larvae must remain in the water column for a minimum of ten days to reach the NEGOM from the CB given prevailing water flow, though 45-50 days provides maximum connectivity. These findings are relevant for invasive species control, fisheries management, ecosystem services, and preserving metapopulations of marine fauna sympatric to the both regions. [ABSTRACT FROM AUTHOR]

Passive acoustic recorders were used to monitor sound production indicative of the use of spawning habitat by groupers (Serranidae) at Riley's Hump, which is located in the Tortugas South Ecological Reserve (TSER), part of the Florida Keys National Marine Sanctuary. Sound production by black grouper (Mycteroperca bonaci), red grouper (Epinephelus morio), and red hind (E. guttatus) was recorded yearround and at all times of day but occurred more often in the evening during the winter-spring spawning period than during other times of the day and year. This pattern for these species is consistent with results of previous studies that documented the association of sound production with reproductive behavior at spawning sites. Distinct diel and seasonal patterns of sound production by the longspine squirrelfish (Holocentrus rufus) and bicolor damselfish (Stegastes partitus) also were recorded. Riley's Hump is a documented spawning site for mutton snapper (Lutjanus analis), and recordings of black grouper, red grouper, and red hind indicate that it is used for reproductive purposes by these species as well. These results showed the importance of the TSER and the need for continued research to understand its role in the recovery and sustainability of managed fish populations. [ABSTRACT FROM AUTHOR]

The goals of this project were to determine the daily, seasonal and spatial patterns of red grouper Epinephelus morio sound production on the West Florida Shelf ( WFS) using passive acoustics. An 11 month time series of acoustic data from fixed recorders deployed at a known E. morio aggregation site showed that E. morio produce sounds throughout the day and during all months of the year. Increased calling (number of files containing E. morio sound) was correlated to sunrise and sunset, and peaked in late summer (July and August) and early winter (November and December). Due to the ubiquitous production of sound, large-scale spatial mapping across the WFS of E. morio sound production was feasible using recordings from shorter duration-fixed location recorders and autonomous underwater vehicles ( AUVs). Epinephelus morio were primarily recorded in waters 15-93 m deep, with increased sound production detected in hard bottom areas and within the Steamboat Lumps Marine Protected Area (Steamboat Lumps). AUV tracks through Steamboat Lumps, an offshore marine reserve where E. morio hole excavations have been previously mapped, showed that hydrophone-integrated AUVs could accurately map the location of soniferous fish over spatial scales of <1 km. The results show that passive acoustics is an effective, non-invasive tool to map the distribution of this species over large spatial scales. [ABSTRACT FROM AUTHOR]

We evaluated eye lenses as potential recorders of stable isotope histories in fish because they consist of metabolically inert optical proteins that are deposited in successive, concentric circles (laminae) much like otolith circuli and tree rings. We conducted four different tests on lenses from red snapper, red grouper, gag, and white grunt. The first test was a low-resolution screening of multiple individuals (4–5 radial groups of laminae per lens, all species except white grunt). Along the radial axis, all individuals exhibited substantial isotopic variability. Red snapper individuals separated into two groups based on δ15N and gag separated into two groups based on δ13C. Two gag with the greatest variation were chosen for high-resolution temporal analysis using individual laminae from their second eye lenses. The first-order patterns from the high-resolution analysis generally mimicked patterns from the low-resolution screening of grouped laminae, yet the high-resolution plots revealed early-life details that were not apparent in the low-resolution screenings. For the third test, left- versus right-eye variation was compared using high-resolution methods. White grunt left- and right-eye radial isotopic patterns were almost identical for both δ13C and δ15N, suggesting the variations observed among individual fish were not artifacts. The final test evaluated intra-laminar variation; multiple samples were analyzed from different parts of the same lamina. Seven laminae from three individuals of two species were analyzed in this manner; variations among laminae were found to be much higher than variations within laminae. However, nominal intra-laminar variations were comparable to nominal differences between left and right lenses, suggesting intra-laminar variation established measurement precision. Eye lens isotopes appear to be useful for reconstructing the isotopic histories of individual fish; these histories can be compared with spatially-derived isoscapes to reconstruct individual histories for site fidelity, movement and trophic position. [ABSTRACT FROM AUTHOR]

A predator-prey model was applied to the red grouper Epinephelus morio fishery from Yucatan, Mexico, with the aim of understanding the spatial behaviour of a mid-sized fishing fleet. The heterogeneity of the environment was considered, and different habitat quality levels were determined to address environmental differences. The behaviour of the fleet was also evaluated based on a simulation of restricted fishing areas (RFA). The model was applied utilising 5 years of information on catch and fishing effort (1973-1977). Four levels of habitat quality were defined (low, medium, high and exceptional). The total costs and revenue for a fishing expedition in the areas of exceptional habitat quality were higher due to their location farthest from the base port. The fleet was most efficient during the winter at locations in the eastern continental shelf, with the number of these areas clearly decreasing in the autumn. The model simulation of the RFA showed a total revenue reduction of 7-27 % in scenarios of RFA for adult protection. When the RFA was implemented for the protection of juvenile fish, the total revenue was not reduced, indicating that this type of RFA might be a feasible management strategy for a sustainable fishery. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Fisheries & Aquatic Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Local fisher knowledge is an important source of information for the adjustment of environmental baselines relative to anthropogenic impacts on marine ecosystems. This knowledge is also susceptible to the shifting baseline syndrome. Four generations of fishers neighbouring a marine park in Eastern Brazil, were surveyed regarding the conservation status of nine reef fish species. Shifts in environmental baselines were detected among fisher generations. Fishers older than 50 years not only caught larger individual fish, but catches of large fish occurred four decades ago, suggesting that bigger fish are in decline in the region. Of nine reef fish species, seven exhibited significant declining catch trends based on information provided by fishers. Such declining status was not reported by all informants of younger generations, so the ability to identify such species increases significantly with fisher age. The fish species most cited as overexploited were Mycteroperca bonaci (Poey), Epinephelus morio (Valenciennes) and Ocyurus chrysurus ( Bloch), emphasising that special attention should be given to the management and conservation of these species in Eastern Brazil. These results also showed that knowledge acquired by elder fishers (> 50 years old) can provide valuable insights into the conservation status of reef fish and the adjustment of environmental baselines for proper management of a marine park. [ABSTRACT FROM AUTHOR]

The article examines the survival of red grouper and red snapper caught on circle and J-hooks by recreational fisheries in Florida. It mentions the difference of delayed hook mortality of both species from blood loss of J-hook nicked internal organs. It notes that the survival rates of the fish correlate with feeding behavior, jaw morphology, and prey residence time. It also emphasizes the higher tag recapture rates for tagged red grouper caught on circle hooks than on J-hooks.

Copyright of Professional Geographer is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

new species of nematode, Philometra morii sp. nov. (Philometridae), is described from males and gravid females collected from the mouth cavity of the red grouper, Epinephelus morio (Valenciennes) (Serranidae, Perciformes), from the northen Gulf of Mexico, off Florida, USA. The new species is characterized mainly by the length of spicules (84-90 and 72-87 μm) and the length (54 μm) and structure of the gubernaculum in the male, and by the presence of three large oesophageal teeth protruding from the mouth, the number and arrangement of small cephalic papillae (8 papillae in 4 pairs of external circle and 6 single papillae of internal circle), the length (1.09-1.50 mm) and structure of the oesophagus and two large papilla-like caudal projections, and by the length of their bodies (19.34-30.07 mm). Philometra morii is the third species of this genus reported from E. morio in the Gulf of Mexico, differing from the two previously described species, in addition to morphological features, by the site of infection in this host (mouth cavity and sinuses vs oculo-orbits or gonads). From the same region (northern Gulf of Mexico, off Florida), gravid females of Philometra Costa, 1845, morphologically and biometrically similar to those of P. morii, were found in the subcutaneous tissues and sinuses of the head of another serranid fish (gag), Mycteroperca microlepis (Good et Bean). Although their conspecificity with P. morii cannot be excluded, they have been designated as Philometra sp. until conspecific males are discovered and described. Based on light and scanning electron microscopy examination (latter used only for females), both these forms are described. [ABSTRACT FROM AUTHOR]

In this article, we consider the potential effects of anthropogenic disturbances on marine fish species known or suspected to be habitat engineers. The three species of interest inhabit different marine habitats at different life stages, and therefore can have significant influences across the sea floor at broad spatial scales. The primary species include the shallow-water Atlantic goliath grouper (Epinephelus itajara), which inhabits mangrove root systems as juveniles, and caves, shipwrecks, and rocky reefs as adults; red grouper (E. morio), which excavates habitat throughout its benthic life in Karst regions of the Gulf of Mexico and western Atlantic, from the coast to the shelf-edge; and tilefish (Lopholatilus chamaeleonticeps), a species that lives on the continental slope and constructs elaborate, pueblo-esque burrows. The anthropogenic disturbances of greatest interest in the Gulf of Mexico include fishing, hypoxia, red tide, oil and gas exploration, and climatic change. We suggest that to understand the broader effects of both natural and anthropogenic disturbances on biomass and productivity in these species requires that we first understand the strength of interactions between them and the other species residing within their communities (e.g., predators, prey, commensals, and mutualists). [ABSTRACT FROM AUTHOR]

Global temperatures are rising, and are expected to produce a poleward shift in the distribution of many organisms. We quantified changes in fish assemblages within seagrass meadows of the northern Gulf of Mexico (GOM) between the 1970s and 2006–2007, and observed changes consistent with this forecast. During 2006–2007 we sampled seagrass meadows using the same gears and methods previously employed by R. J. Livingston in coastal waters of northwest Florida throughout the 1970s. Comparisons between datasets revealed numerous additions to the fish fauna during 2006–2007 that were completely absent in the 1970s, including: Lutjanus synagris (lane snapper), Epinephelus morio (red grouper), Chaetodon ocellatus (spotfin butterflyfish), Mycteroperca sp (grouper, non gag), Centropristis philadelphica (rock sea bass), Fistularia tabacaria (bluespotted cornetfish), Ocyurus chrysurus (yellowtail snapper), Thalassoma bifasciatum (bluehead wrasse), Abudefduf saxatilis (sergeant major), Acanthuridae spp. (surgeonfishes) and Sparisoma viride (stoplight parrotfish). Several other species showed large increases in abundance during the interval between 1979 and 2006, including Mycteroperca microlepis (gag grouper, up ∼200 ×), Lutjanus griseus (gray snapper, up ∼105 ×), and Nicholsina usta (emerald parrotfish, up ∼22 ×). All of these are tropical or subtropical species that now make up a greater percentage of seagrass-associated fish assemblages in the northern GOM than in the past. Additionally, we observed regional increases in air and sea surface temperatures (> 3 °C) during the ∼30 years that separate Livingston's samples and ours that correlate with northern shifts in the distribution of warm-water fishes. Documenting these range shifts is a critical first step in investigating the consequences of global warming for endemic marine communities and fishery production in the northern GOM. [ABSTRACT FROM AUTHOR]

The article discusses a study which analyzed the spatial-seasonal variation in catchability of the red grouper Epinephelus morio fishery in the Campeche Bank, northern coast of the Yucatan Peninsula using data from 1973 to 1977. It reveals that the adult catchability was higher during the reproductive period in the eastern part of the region. The researchers recommend that coastal areas near Celestún, Dzilam de Bravo, Rio Lagartos, and El Cuyo, be considered as fishing restricted areas to limit fishing mortality and promote stock recovery.

Food poisoning due to ingestion of an unknown red grouper occurred in southern Taiwan. To identify the species of toxic red grouper implicated in food poisoning, a 475-bp sequence of the cytochrome b gene from six species of fresh red grouper meat was amplified by using a pair of primers (L14735/H15149). This fragment could be amplified when fish meat was treated with different heating processes. After sequencing, it was found that no variation in sequences was detected among individuals within each species. The species of toxic red grouper meat implicated in food poisoning was judged to be Lutjanus bohar based on sequence analysis. In addition, restriction enzyme analysis with HaeIII rapidly distinguished these six species of red grouper and the two samples implicated in food poisoning. No toxicity of viscera in 18 specimens of six red grouper species was detected, but two food poisoning samples were found to be toxic. This study indicated that DNA sequence and restriction enzyme analysis are powerful methods for identifying potentially toxic red grouper species as L. bohar. [ABSTRACT FROM AUTHOR]

To be as accurate as possible, stock assessments should account for discard mortality in fisheries if it occurs. Three common approaches to modeling discards in assessments are to lump dead discards with landings, treat dead discards as their own fleet, or link them conversely with landings through use of a retention function. The first approach (lumping) implicitly assumes that the selectivity of landings applies also to discards. In many cases, that assumption is false, for example, if discards comprise smaller fish than do landings. The latter two approaches avoid the assumption by modeling discards explicitly with their own selectivity pattern. Here, we examine these approaches to modeling discards. Using a simulation study, we demonstrate that the two approaches to modeling discards explicitly can provide identical results under both static and time-varying conditions. Then, using a stock assessment case study of red grouper Epinephelus morio in the U.S. Gulf of Mexico, we demonstrate that in practice the approaches to modeling discards can provide different outcomes, with implications for the resultant management advice. We conclude by comparing and contrasting the different approaches, calling for more research to elucidate which approach is most suitable under various sources of error typically encountered in discard data. [ABSTRACT FROM AUTHOR]

The objective of this study was to arrive at biologically convincing estimates of the natural mortality rate (M) for different life history stages of the red grouper Epinephelus morio on Campeche Bank, Mexico. Estimates of M must be compatible with our knowledge of life histories and are essential as input to analytical assessment models for any exploited stock. Because of difficulties in estimating M directly, M has often been incorrectly assumed to be constant with age for a fishery harvesting different age-groups. The gnomonic interval method (GIM) was applied to this long-lived species to estimate a vector of M-values for successive life history stages. The GIM estimates the vector of M at age from the duration of successive development stages and the mean annual fecundity. Estimates were calibrated using available independent data. We computed the relationship between M and age (t) over a 13-year period as Mt = 0.8976t-0.93. Values of M estimated by GIM for adult red grouper were not significantly different (P > 0.05) from those reported in the literature. [ABSTRACT FROM AUTHOR]

Distribution patterns of catchability were evaluated for the red grouper Epinephelus morio (Serranidae) on the Campeche Bank off the northern Yucatan coast of Mexico. Catchability-at-length values were estimated with a method based on a transition matrix. Five years of catch and effort data for the Mexican mid-fleet were used for the estimation procedure. Two main patterns were found within the bank. The first occurred in the deepest areas and in the eastern part of the bank, where catchability increased with size. The second was close to the coasts, where lower values of catchability were observed, even in large sizes. These results suggest that the main area of aggregation for reproduction with higher values of catchability is in the eastern part of the bank (22–23°N, 87–88°W). Catchability differences suggest that spatial management policies must be implemented to allow depleted stock to recover. [ABSTRACT FROM AUTHOR]

The article discusses the life history of the red grouper (Epinephelus morio) in North and South Carolina. The 2,146 sample specimens of red grouper have a total length range of 315 to 851 millimeter with the age range of 2 to 20 years. The von Bertalanffy growth equation was used to describe the length-at-age, while the sex type was assessed using histological analysis. It was determined that red groupers are protogynous hermaphrodite or their sex type changes as they mature.

The genetic population structure of red grouper, Epinephelus morio (Valenciennes), and scamp, Mycteroperca phenax Jordan and Swain, from the southeastern U.S. Atlantic coast and the Gulf of Mexico was examined using nuclear microsatellite DNA markers in order to test the null hypothesis of panmixia throughout this range. Physical and biological data indicate that relatively isolated populations of these fish exist. Genetic variation was assessed at four microsatellite loci in red grouper and six loci in scamp. The fish were collected on different dates between 1991 and 2001. The microsatellite loci were highly polymorphic, with an average expected heterozygosity of 0.75 in red grouper and 0.68 in scamp. Heterozygote deficiencies (significant deviations from Hardy–Weinberg equilibrium, HWE) were found at two of four loci in all red grouper samples except the eastern Gulf of Mexico, and for all red grouper combined. In contrast, all loci conformed to HWE in the separate scamp samples. Minimal genetic differences distinguished southeastern U.S. Atlantic or Mexican red grouper from other localities, and no indication of genetic differentiation was observed in scamp. This large-scale genetic homogeneity may be attributed to ongoing gene flow and/or historical contact between present-day populations. For management purposes, genetic homogeneity does not necessarily imply a single stock. Because larval dispersal may be sufficient to homogenize gene frequencies but not to replenish depleted stocks, other data must be considered in the management of these species. [ABSTRACT FROM AUTHOR]

The purpose of this study were to: (i) develop mitochondrial (mt)DNA probes for two species-groups of reef fishes, and (ii) assay mtDNA restriction fragment length polymorphism (RFLP) variation in two reef fish species from the Gulf of Mexico. MtDNA probes for groupers of the genera Epinephelus and Mycteroperca and for jacks of the family Carangidae were generated and mtDNA fragment patterns of 34 enzymes were assayed from samples of red grouper (Epinephelus morio) and greater amberjack (Seriola dumerilli). Ten polymorphic restriction enzymes (yielding 12 distinct mtDNA haplotypes) were identified in the red grouper, while 19 polymorphic enzymes (yielding 23 distinct mtDNA haplotypes) were identified in greater amberjack. Estimates of percentage nucleotide-sequence divergence among haplotypes ranged from 0.09–0.59 (mean ± S.E. = 0.29 ± 0.02) in red grouper and from 0.09–1.32 (mean ± S.E. = 0.49 ± 0.02) in greater amberjack. Estimated mtDNA nucleon diversity values were 0.418 and 0.900 for red grouper and greater amberjack, respectively. Estimated intrapopulational percentage nucleotide diversities were 0.078 ± 0.003 (mean ± S.E.) for red grouper and 0.336 ± 0.006 (mean ± S.E.) for greater amberjack. Estimates of the evolutionary effective female population size (Nflel) were generated for both species and compared to Nflel values for eight other marine fish species or subspecies. The Nflel value for greater amberjack was more or less intermediate, whereas the Nflel value for red grouper was low. The latter may indicate that red grouper warrant immediate management attention. Heterologous hybridizations to mtDNAs of two other species of Epinephelus (E. adscensionis and E. fulvus) and to Myeteroperca phenax (using the red grouper probe), and to mtDNA of the horse-eye jack, Curanx lutus (using the greater amberjack probe), were successful. MtDNA data generated from red grouper and greater amberjack, as well as the potential to obtain mtDNA data from other grouper and carangid species, should prove useful in future studies of genetic variation and population differentiation in these important reef fishes. [ABSTRACT FROM PUBLISHER]

Chlorine dioxide (CIO2) has been explored as a potential substitute for aqueous chlorine to clean seafood products. In an attempt to understand the interaction of CIO2 with organic compounds, duplicate fillets of Atlantic salmon ( Salmo salar) and red grouper ( Epinephelus morio) were treated for 5 min with freshly prepared aqueous CIO2 at 20, 40, 100, and 200 ppm total available CIO2 in 3.5% brine. Thiobarbituric acid (TBA) values and fatty acid composition were determined. CIO2-treated salmon and red grouper showed a dose-related increase in TBA; the 100 and 200 ppm groups had significantly ( P<0.05) greater TBA values than controls and the 20 ppm group. Treated red grouper and salmon did not differ in percentage monounsaturated and polyunsaturated fatty acids compared to controls, although differences occurred with some individual fatty acids. Thus, CIO2 treatment did not greatly affect fatty acid composition of treated fillets. [ABSTRACT FROM AUTHOR]

A correction to the article "Life history of red grouper (Epinephelus morio) off the coasts of North Carolina and South Carolina" that was published in the previous issue is presented.