The summer flounder chronicles: Science,politics, and litigation, 1975–2000

The summer flounder, or fluke (Paralichthys dentatus)supports the most important commercial and recreational flatfishfisheries of the U.S. Atlantic coast. Thestock and fishery range from Massachusetts toNorth Carolina. Spawning takes place during aprotracted season that can extend fromSeptember to March, during an annual offshoreand southern migration to the outer continentalshelf off Virginia and North Carolina. Thefish are con-centrated in bays and estuariesfrom late spring through early autumn, when thenext offshore migration begins. The assessmentand management of the summer flounder fisheryhas been very contentious since theimplementation of the joint Atlantic StatesMarine Fisheries Commission/Mid-AtlanticFishery Management Council Fishery ManagementPlan (FMP) in 1989, when the poor status of thesummer flounder stock was evident toscientists, managers, and fishermen. Amendment2 to the FMP, approved in 1992, implementedseveral major regulatory provisions includingannual commercial quotas and recreationalharvest limits, and annually adjustable minimumlanded fish sizes, minimum mesh sizes,possession limits, and seasonal closures. By1999, fishing mortality on summer flounder haddeclined to its lowest level since the 1960s,and summer flounder total stock biomass was thehighest since the mid-1970s. Monitoring ofstock status is ongoing to reliably determine``how much fish is enough' to provide forlong-term sustainability. Many changes are madeannually to management measures due todiffering interpretations of stock status bymanagers, and fishery and environmentaladvocacy groups. Attainment of the annualfishing mortality targets remains elusive. Themultiple layers of science, management, andpolitics in place since 1992 continue to sparkmuch controversy and litigation that increasingly places the management of the summer flounder fishery in the hands of the courts.     

Patterns of resorption of vitellogenous oocytes in the striped flounder Pleuronectes pinnifasciatus

Two patterns of resorption of vitellogenous oocytes with the participation of follicular cells, differing in their morphological features, were revealed in the striped flounder Pleuronectes pinnifasciatus. In the prespawning season, the resorption affected a small number of oocytes with yolk granules and resembled in some features (destruction of the nucleus and radial coating) the atresia of ovarian follicles in many fish species previously studied. In the spawning season, resorption was specified by accretion of the follicular epithelium and release of the homogenized yolk from the oocytes to the follicular wall. No destruction of the radial coating was observed in that case, and the trophic material was utilized in protrusions of the follicular wall.     

A critical period for nutritional control of early gametogenesis in female winter flounder, Pleuronectes americanus (Pisces: Teleostei)

When female winter flounder ( Pleuronectes americanus ) were subjected to periods of satiation feeding alternating with starvation it was found that the first part of their normal six-month feeding period could be associated with subsequent gametogenesis, whereas feeding in the later part of the normal feeding period was not necessary. Conversely if females were not fed during the first part of the normal feeding season they were likely to become non-reproductive, although high condition fish or a non-spawner could become gametogenic in spite of starvation at this time. Feeding restricted to the later part of the normal feeding season was therefore not generally associated with successful gametogenesis for the following year's spawn. When the first part of the feeding period was further subdivided with satiation feeding limited to one or more months within it, most fish became non-reproductive. The exceptions which became reproductive were females which had high post-spawn condition maintained in the month following the immediate spawning period for the individual fish. A nutritionally sensitive period for early gametogenesis in female winter flounder therefore appears to occur in the early part of the normal feeding season, close to the normal spawning period. The experimentally produced non-reproductive females were generally halted in a previtellogenic stage of development for the most advanced oocytes which is consistent with a nutritionally related inhibition of gametogenesis close to the previous spawning period.     

Predator-prey relations between age-1+ summer flounder (Paralichthys dentatus, Linnaeus) and age-0 winter flounder (Pseudopleuronectes americanus, Walbaum): predator diets, prey selection, and effects of sediments and macrophytes

Laboratory experiments and weekly trammel net surveys in the Navesink River, New Jersey (USA) were used to examine the predator-prey interaction between age-1+ summer flounder (Paralichthys dentatus) and age-0 winter flounder (Pseudopleuronectes americanus). Winter flounder (24-67 mm TL) were the dominant piscine prey of summer flounder (n=95, 252-648 mm TL) collected in trammel nets. We observed a temporal shift in summer flounder diets from sand shrimp (Crangon septemspinosa) and winter flounder, dominant during June and early July, to blue crabs (Callinectes sapidus) and other fishes (primarily Atlantic silversides, Menidia menidia and Atlantic menhaden, Brevortia tyrannus) later in the summer. Variations in prey selection appeared to be related to changes in the spatial distribution of predators and spatio-temporal variation in prey availability. In laboratory experiments, summer flounder (271-345 mm total length, TL) preferred demersal winter flounder to a pelagic fish (Atlantic silversides) and a benthic invertebrate (sand shrimp) prey, and the vulnerability of winter flounder increased with increasing prey body size from 20 to 90 mm TL. Experiments testing habitat effects showed that mortality of winter flounder in three different size classes (20-29, 40-49, 60-69 mm TL) was not influenced by sediment grain sizes permitting differential burial of the prey. However, vegetation enhanced survival, with fish suffering lower mortality in eelgrass (Zostera marina, 15+/-0.04%) than in sea lettuce (Ulva lactuca, 38+/-0.04%) or bare sand (70+/-0.07%) when the macrophytes were planted to produce similar leaf surface areas (5000 cm(2) m(-2)). Prey vulnerability appeared to be related to the role of vision in the predator's attack strategy and prey activity levels.     

Comparison of antibodies in marine fish from clean and polluted waters of the New York Bight: relative levels against 36 bacteria.

Fish from polluted waters are subject to increased prevalence of disease. Because they respond to bacterial pathogens by producing serum antibodies, it was possible to construct a seasonal serological record in three fish species from clean and polluted waters of the New York Bight. Antibody levels were determined by testing sera for agglutinating activity against 36 strains of bacteria. Evaluation of 5,100 antibody titrations showed the following. During warm months, summer flounder (Paralichthys dentatus) from the polluted area had significantly higher antibody levels and antibody to a greater diversity of bacteria than fish from the unpolluted area. Weakfish (Cynoscion regalis) from the same polluted area shared with summer flounder raised titers to many bacteria. The greatest proportion of raised titers was against Vibrio species, although prominent titers were also seen against Aeromonas salmonicida and Haemophilus piscium, bacteria usually associated with diseases in freshwater but not marine fish. Differences between polluted and clean waters were not as evident in winter flounder (Pseudopleuronectes americanus) during cold months. This could be due, in part, to reduced antibody production at colder temperatures. The data illustrate the usefulness of the serum antibody record in identifying environmental exposure to bacteria in marine fish and indicate that the polluted New York Bight apex has increased levels and diversity of bacteria during warm months.     

Comparison of antibodies in marine fish from clean and polluted waters of the New York Bight: relative levels against 36 bacteria

Fish from polluted waters are subject to increased prevalence of disease. Because they respond to bacterial pathogens by producing serum antibodies, it was possible to construct a seasonal serological record in three fish species from clean and polluted waters of the New York Bight. Antibody levels were determined by testing sera for agglutinating activity against 36 strains of bacteria. Evaluation of 5,100 antibody titrations showed the following. During warm months, summer flounder (Paralichthys dentatus) from the polluted area had significantly higher antibody levels and antibody to a greater diversity of bacteria than fish from the unpolluted area. Weakfish (Cynoscion regalis) from the same polluted area shared with summer flounder raised titers to many bacteria. The greatest proportion of raised titers was against Vibrio species, although prominent titers were also seen against Aeromonas salmonicida and Haemophilus piscium, bacteria usually associated with diseases in freshwater but not marine fish. Differences between polluted and clean waters were not as evident in winter flounder (Pseudopleuronectes americanus) during cold months. This could be due, in part, to reduced antibody production at colder temperatures. The data illustrate the usefulness of the serum antibody record in identifying environmental exposure to bacteria in marine fish and indicate that the polluted New York Bight apex has increased levels and diversity of bacteria during warm months.     

The summer flounder chronicles II: new science,new controversy, 2001–2010

The summer flounder, or fluke, Paralichthys dentatus, supports the most important commercial and recreational flatfish fisheries of the US Atlantic coast. The stock and fishery range from Massachusetts to North Carolina. The assessment and management of the summer flounder fishery has been very contentious since implementation of the joint Atlantic States Marine Fisheries Commission/Mid-Atlantic Fishery Management Council Fishery Management Plan (FMP) in 1989, when the poor status of the summer flounder stock was evident to scientists, managers, and fishermen. Management efforts to control fishing mortality in the face of increasing stock abundance and competing demand for fish from both the commercial and recreational sectors continue to evoke the question of “How much fish is enough?” to provide for long-term sustainability. In spite of the numerous controversies, however, by 2010 the fishing mortality on summer flounder had declined to its lowest level in at least 30 years, and summer flounder stock biomass was the highest since the stock assessments began in the 1960s. From a scientific perspective, future assessments need to: (a) better account for the uncertainty resulting from “internal model” retrospective error, (b) better integrate environmental, ecological, and other non-traditional calibration indices into the modeling framework, and (c) better discern summer flounder stock-recruitment dynamics by considering covariates such as environmental factors and predator/prey abundance. Initiatives are underway to acquire improved fishery and biological data to allow the assessments to better reflect the true “state of nature.”     

Comparative study of reproductive biology in single- and multiple-spawner cyprinid fish. I. Morphological and histological features

To clarify the dynamics and regulation of oogenesis in single- and multiple-spawning cyprinid fish with group-synchronous oocyte development, a multidisciplinary approach to their reproduction was undertaken using three species from the River Meuse (Belgium): the roach Rutilus rutilus as a single spawner, and the bleak Alburnus alburnus and the white bream Blicca bjoerkna as multiple spawners. The gonadosomatic index (GSI) and histomorphometric changes (distribution of oocyte size, relative proportion of the various oocyte stages) in the ovary are compared. Different patterns of GSI and oocyte growth were observed both between the single- and multiple-spawner fish and between the two multiple spawners. Maximum GSIs were higher in roach (21%) than in bleak and white bream (17.7 and 14.5%, respectively), and compared to the rapid decline of GSI in the roach population, the GSI of multiple spawners decreased progressively during the spawning season. In roach, a short gonadal quiescent period and an early onset of vitellogenesis was recorded from late summer onwards whereas, in bleak and white bream, exogenous vitellogenesis was not systematically observed before winter. A protracted spawning season and/or a low water temperature in autumn are hypothesized to explain this long period of gonadal quiescence. In bleak, during the spawning season, the oocytes recruited arose from the stock of endogenous vitellogenesis and attained the final maturation stage very rapidly. This recruitment occurred during the whole spawning season. In white bream, the differentiation of vitellogenic oocytes from smaller oocytes was completed before the onset of the spawning season. During the spawning period, the proportion of vitellogenic oocytes decreased progressively whereas the percentage of oocytes in the final maturation stage remained approximately constant.     

A comparison of the effect of captivity on the epidermis of prespawning and postspawned winter flounder, Pseudopleuronectes americanus

The effect of captivity on the epidermis of Pseudopleuronectes americanus Walbaum is influenced by the phase of the reproductive cycle. Towards the end of the prespawning period captive male flounder had a higher GSI than flounder from the wild population, and the seasonal epidermal sexual dimorphism in these captive flounder was more pronounced. Flounder maintained in the laboratory during the postspawning period manifested a thick epidermis and increased mucigenesis in late summer, when these characteristics displayed seasonally low values in the inshore population from which the flounder were sampled. Possible regulatory factors and implications for protocols involving captive fish are discussed.     

An experimental investigation of the non-reproductive, post-mature state in winter flounder

Winter flounder from known locations were sorted according to their reproductive status about 4 weeks before spawning. Five groups were then fed to satiation and three groups were not fed. The experiment was terminated at the end of the summer feeding season. At termination, only one of the recently spawned fish with restricted feeding showed gonad recrudescence. Conversely, all previously reproductive fish which had been fed to satiation showed gonad recrudescence. Fish fed to satiation included some which had been initially designated non-reproductive post-mature. These experiments indicate that a non-reproductive post-mature state is inducible and may be reversible, with the switch related to nutritional status.     

Infectious necrotizing enteritis and mortality caused by Vibrio carchariae in summer flounder Paralichthys dentatus during intensive culture

An epizootic causing mortality among cultured summer flounder Paralichthys dentatus occurred in summer of 1998 at a land-based facility on Narragansett Bay, Rhode Island, USA. The disease, flounder infectious necrotizing enteritis (FINE), was characterized by reddening around the anal area, distended abdomens filled with opaque serosanguineous fluid, enteritis and necrosis of the posterior intestine. In extreme cases of the disease, the posterior intestine was detached from the anus and was observed coming out the vent. The intestine of individuals that recovered from the disease ended in a blind-sac; the abdomens of these fish were distended, due to food and water inside the intestinal blind-sac. A bacterium was isolated from ascites fluid and kidney of moribund flounder and identified as the causative agent in challenge experiments. The pathogen was identified as Vibrio carchariae by morphological and biochemical characteristics and sequence of the 16S rRNA. The LD50 estimate was 5 x 10(5) colony-forming units injected intraperitoneally into 100 to 200 g summer flounder.     

Molecular cloning and characterization of two novel human renal organic anion transporters (hOAT1 and hOAT3)

The cloned organic anion transporters from rat, mouse, and winter flounder (rOAT1, mOAT1, fROAT) mediate the coupled exchange of alpha-ketoglutarate with multiple organic anions, including p-aminohippurate (PAH). We have isolated two novel gene products from human kidney which bear significant homology to the known OATs and belong to the amphiphilic solute facilitator (ASF) family. The cDNAs, hOAT1 and hOAT3, encode for 550- and 568-amino-acid residue proteins, respectively. hOAT1 and hOAT3 mRNAs are expressed strongly in kidney and weakly in brain. Both genes map to chromosome 11 region q11.7. PAH uptake by Xenopus laevis oocytes injected with hOAT1 mRNA is increased 100-fold compared to water-injected oocytes. PAH uptake is chloride dependent and is not further increased by preincubation of oocytes in 5 mM glutarate. Uptake of PAH is inhibited by probenicid, alpha-ketoglutarate, bumetanide, furosemide, and losartan, but not by salicylate, urate, choline, amilioride, and hydrochlorothiazide.     

Effects of the dioxin-like PCB 126 on larval summer flounder (Paralichthys dentatus)

Little is known about the sensitivity of teleost post-embryonic developmental stages (larval and metamorphic) to dioxin-like compounds. Larval and metamorphosing summer flounder (Paralichthys dentatus) were exposed to the dioxin-like polychlorinated biphenyl congener PCB 126, to compare their sensitivity to other fish species early life stages, and to document effects on metamorphic development, including degree of eye migration and gastric maturation. Median lethal doses (LD 50 s) ranged between 30 and 220 ng/g wet mass, indicating that pre- and early-metamorphic stages of summer flounder are equally sensitive to the embryos of some of the most vulnerable fish species tested. Consistent with the presence of a functional aryl hydrocarbon receptor pathway, dose-dependent induction of cytochrome P-4501A (CYP1A) at four days post-exposure was observed in liver, stomach, intestine, and kidney of metamorphosing larvae. Stage-dependent differences in the epithelial distribution of CYP1A immunoreactivity were observed in the developing stomach of fish exposed to relatively high PCB 126 doses. A single sublethal dose (15 ng/g) delayed metamorphic progress (determined by the degree of eye migration), and resulted in abnormally high levels of cell proliferation and abnormal gastric gland morphology in late metamorphic stages. These results suggest that the post-embryonic larval and metamorphic stages of summer flounder, and potentially other fish species with complex life histories, are vulnerable to the effects of dioxin-like compounds, including lethality, developmental delay, and malformations.     

Impacts of diclidophorid monogenean infections on fisheries in Japan

Many monogeneans are pathogenic to economically important fish in Japan. However no other monogenean is comparable with the diclidophorids, Heterobothrium okamotoi and Neoheterobothrium hirame, on the scale of impacts they inflict on Japanese fisheries. The shared importance of the two monogenean infections lies in their pathogenicity, fecundity and tolerance to chemical treatment. Heterobothrium okamotoi infects the gills and wall of the branchial cavity of the tiger puffer, Takifugu rubripes (Tetraodontidae), which is widely cultured in western Japan. The main presenting signs of infected fish are anaemia and extensive necrosis caused by adult worms. This monogenean deposits long strings of eggs, which reach lengths of almost 3m. Egg entanglement with the mesh of culture nets increases the chance of hatched larvae encountering susceptible fish. The oncomiracidium maintains infectivity for up to 4 days after hatching. Hydrogen peroxide is the only commercially available chemical able to control the infection, but can only kill immature worms on the gills. Neoheterobothrium hirame infects the gills and wall of the buccal cavity of the Japanese flounder, Paralichthys olivaceus (Paralichthyidae). Since the first known occurrence of this monogenean in 1993, the species has been recorded from almost all areas where the host is distributed. Neoheterobothrium hirame has the potential to produce 781 eggs per day at 20 degreeC. In the western Sea of Japan, wild young-of-the-year flounder became infected in early summer, followed by a sharp increase in prevalence in late summer. By late summer, juvenile flounder have nearly disappeared from the area, strongly suggesting that N. hirame is responsible for mortality of young fish. This is in good agreement with the recent decline in the local flounder population. Neoheterobothrium hirame has also been considered the causative agent of anaemia among wild Japanese flounder since the late 1990s.     

The flounder organic anion transporter fOat has sequence, function, and substrate specificity similarity to both mammalian Oat1 and Oat3

The flounder renal organic anion transporter (fOat) has substantial sequence homology to mammalian basolateral organic anion transporter orthologs (OAT1/Oat1 and OAT3/Oat3), suggesting that fOat may have functional properties of both mammalian forms. We therefore compared uptake of various substrates by rat Oat1 and Oat3 and human OAT1 and OAT3 with the fOat clone expressed in Xenopus oocytes. These data confirm that estrone sulfate is an excellent substrate for mammalian OAT3/Oat3 transporters but not for OAT1/Oat1 transporters. In contrast, 2,4-dichlorophenoxyacetic acid and adefovir are better transported by mammalian OAT1/Oat1 than by the OAT3/Oat3 clones. All three substrates were well transported by fOat-expressing Xenopus oocytes. fOat K(m) values were comparable to those obtained for mammalian OAT/Oat1/3 clones. We also characterized the ability of these substrates to inhibit uptake of the fluorescent substrate fluorescein in intact teleost proximal tubules isolated from the winter flounder (Pseudopleuronectes americanus) and killifish (Fundulus heteroclitus). The rank order of the IC(50) values for inhibition of cellular fluorescein accumulation was similar to that for the K(m) values obtained in fOat-expressing oocytes, suggesting that fOat may be the primary teleost renal basolateral Oat. Assessment of the zebrafish (Danio rerio) genome indicated the presence of a single Oat (zfOat) with similarity to both mammalian OAT1/Oat1 and OAT3/Oat3. The puffer fish (Takifugu rubripes) also has an Oat (pfOat) similar to mammalian OAT1/Oat1 and OAT3/Oat3 members. Furthermore, phylogenetic analyses argue that the teleost Oat1/3-like genes diverged from a common ancestral gene in advance of the divergence of the mammalian OAT1/Oat1, OAT3/Oat3, and, possibly, Oat6 genes.     

Reproduction of the summer flounder, Paralichthys dentatus (L.)

The reproduction of summer flounder, Paralichthys dentatus (L.), occurring in the Middle Atlantic Bight was studied from 1974–1979. Males dominated the length interval between 21–35 cm t.l. and were essentially absent in samples >55 cm t.l. Females were more abundant in all length intervals >45 cm t.l. Length at maturity ranged from 24–27 cm t.l. for males and from 30–33 cm t.l. for females which coincided with length at age two. Ovarian egg diamerter frequencies indicated summer flounders are serial spawners and the trend in mean and maximum maturity indexes (% ovary weight of total fish weight) indicated spawning began in September and continued through February in 1975 and probably into March in 1976. Annual condition cycle of males peaked in September and was lowest in April while females' cycle reached a maximum in October which coincided with peak spawning time. Fecundity was related to length, weight and ovary weight for 1974–1977 and the length-fecundity equation F = 0.0007975 L ^3.402 was found to be the best predictive relationship. The overall reproductive strategy of summer flounder was discussed and apparently tends to maximize reproductive potential through an extended spawning season, early maturation, high fecundity, serial spawning and extensive spawning migrations.     

Time course of oocyte development in winter flounder Pseudopleuronectes americanus and spawning seasonality for the Gulf of Maine,Georges Bank and southern New England stocks

Winter flounder Pseudopleuronectes americanus were collected at monthly intervals from December 2009 to May 2011, to describe the pattern and seasonality of oocyte development, including: (1) the group‐synchronous transition from primary to secondary oocytes that initiates immediately after spawning, (2) the slow (months) development of vitellogenic oocytes followed by the rapid (weeks) maturation of oocytes, (3) the synchronous nature of mature oocytes ovulating, but the discrete releases of benthic eggs in batches, (4) the protracted (months) degradation of postovulatory follicles and (5) the occurrence of follicular atresia. Although fish were collected across only c. 2° latitudinal range, the spawning season was c. 1 month later in the Gulf of Maine (GOM) than on Georges Bank and in southern New England. This is probably due to lower temperatures in the GOM. These stock‐specific data regarding the time course of oogenesis are of practical value. This information is discussed in relation to measuring and interpreting elements of reproductive potential such as maturation, skipped spawning and fecundity, the response of reproductive traits by this widely distributed species to changing climate and the response by this common, marine‐estuarine species to urbanization, particularly environmental pollutants and dredging.     

Pathogenesis of Gastroenteritis Caused by Vibrio carchariae in Cultured Marine Fish

Serious mortality among the cultured grouper Epinephelus coioides, characterized by a swollen intestine containing yellow fluid (gastroenteritis), occurred in 1993 in Taiwan. A bacterium isolated from the intestinal fluid and head kidney of moribund groupers was identified as Vibrio carchariae. Since then, the same Vibrio species has also been isolated from moribund black sea bream Acanthopagrus schlegeli, yellowfin sea bream A. latus, Japanese sea bass Lateolabrax japonicus, and red drum Sciaenops ocellatus suffering from the same syndrome. Each isolate was virulent to the respective fish. Recently, a similar syndrome, flounder infectious necrotizing enteritis, also caused by V. carchariae in summer flounder Paralichthys dentatus, was reported in Rhode Island. The extracellular products (ECPs) of V. carchariae strains EmI82KL (from grouper), Rd (from red drum), and SfUSA (from summer flounder, U.S.A.) were virulent to the grouper or red drum. A 33-kDa serine protease partially purified from the ECP of strain EmI82KL was lethal to the fish. All the moribund or killed fish exhibited gastroenteritis except those killed within 12 hours. This report is the first to show that intraperitoneal injection of the ECP or protease in the fish is virulent and can reproduce gastroenteritis. The serine protease was suggested as a major toxin in the grouper or red drum secreted by V. carchariae.     

Sinking rates of late-stage fish larvae: Implications for larval ingress into estuarine nursery habitats

Many species spawn in oceanic waters yet their juvenile stages use nearshore and estuarine habits and the bio-physical mechanisms by which late-larvae enter these juvenile habitats may be an important bottleneck in the population dynamics of these species. To provide parameters for the development of larval ingress models, sinking rates were measured of the late-stage larvae of six fish species: Atlantic croaker (Micropogonias undulatus), spot (Leiostomus xanthurus), Atlantic menhaden (Brevoortia tyrannus), summer flounder (Paralichthys dentatus), southern flounder (P. lethostigma), and gulf flounder (P. albigutta). Species-specific differences were found in sinking rates; Atlantic croaker had the slowest sinking rates and Atlantic menhaden and the three flounder species had the fastest sinking rates. Additionally, sinking rates increased for all species as length increased. The total amount of variability explained in sinking rates was low (20–50%), indicating a large amount of variability at the level of the individual. The observed patterns in sinking rates were then combined with previous studies on the mechanisms of larval ingress to present species-specific conceptual models of ingress.     

Reproductive biology of wahoo, Acanthocybium solandri, off eastern Australia

A dearth of basic biological information for wahoo, Acanthocybium solandri, currently hinders the ability of scientists and managers to assess population sustainability and appropriately manage the dramatically increasing global catch. This study examined the gonads of 382 wahoo collected off eastern Australia during 2008–2011 to quantify their reproductive biology in the region. The overall sex ratio of the sample was 3.2:1 (females:males), however this differed significantly among fishing sectors and areas. The estimated fork length at which 50 % of female wahoo reach maturity was 1,046 mm. Similar to the Atlantic Ocean, female wahoo have a protracted summer spawning season during October-February. The mean spawning frequency of female wahoo was uncertain but may be approximately 2–3 days, with evidence of fish actively spawning on consecutive days. Batch fecundity of females was positively correlated with fish size and estimates ranged between 0.65 and 5.12 million oocytes. Relative fecundity was estimated at 122.0 (±9.7) oocytes per gram of ovary free body weight and did not differ with fish size or throughout the spawning season. Estimation of reproductive parameters such as size- and age-at-maturity may facilitate the construction of per-recruit stock assessments of wahoo in the region.