Resumen En los últimos 4 años, Uruguay ha experimentado una creciente demanda por el consumo de alimentos a base de pescado crudo, tales como sushi, sashimi y ceviche. Este escenario generó la necesidad de evaluar la presencia y concentración de parásitos zoonóticos (Nematoda: Anisakidae) en porciones comestibles de especies de pescado comercializadas en el mercado local. Se analizaron 233 ejemplares de tres especies de pescado comercializadas en Uruguay: Macrodon ancylodon, Micropogonias furnieri y Cynoscion guatucupa. Se cuantificaron e identificaron, a nivel de género, nematodos en cavidad celómica y músculo, estableciendo finalmente los descriptores ecológicos para cada género encontrado y para cada especie de pescado evaluada. Dos de las especies evaluadas se encontraban parasitadas a nivel de cavidad celómica y tejido muscular, M. ancylodon y C. guatucupa. Cynoscion guatucupa resultó la especie mayormente parasitada con una prevalencia de 46%, mientras que el género de anisákido más prevalente fue Contracaecum (prevalencia de 35,1% en C. guatucupa y 32,4% en M. ancylodon). El hallazgo de anisákidos en la especie M. ancylodon representa un nuevo registro de hospedador en Uruguay. Por otra parte, se reporta por primera vez en el país la presencia de estos parásitos zoonóticos en porciones comestibles (músculo).

Abstract In the last 4 years, Uruguay has experienced a growing demand of raw fish-based foods, such as sushi, sahimi and ceviche. This scenario generated the need to assess the presence and concentration of zoonotic parasites (Nematodoes: Anisakidae) in edible parts of fish species traded in the local market. 233 fish specimens of 3 species commercialized in Uruguay were analyzed: Macrodon ancylodon, Micropogonias furnieri and Cynoscion guatucupa. The nematodes were quantified and identified at genus level, from coelomic cavity and muscle of the fishes, to finally stablish the ecological descriptors for each genus founded and for each fish species evaluated. Two of the three species of fish were parasitized with anisakids in both location (coelomic cavity and muscle), M. ancylodon and C. guatucupa. C. guatucupa was the most parasitized with a prevalence of 46%, while, the anisakid genus most prevalente was Contracaecum (prevalence of 35,1% in C. guatucupa and 32,4% in M. ancylodon). The finding of anisakids in M. ancylodon represents a report of a new host in Uruguay. Moreover, the finding for the first time in the country of these zoonotic parasites in edible parts of fish (muscle) is highlighted.

Abstract The weakfishes, Cynoscion guatucupa and C. jamaicensis, are important demersal fishery resources and are targeted by multifleet operations in the Southwest Atlantic. This study describes the length-weight relationships between sagittae otoliths (length-OL, height-OH, thickness-OT, and weight-OWT) and the sizes of the fish (total length-LT, standard length-LS, and total weight-WT). The proportion between otolith length and height (aspect ratio-OAR) was also compared between species. The samples were obtained monthly from March 2017 to February 2018 from small-scale commercial fisheries from landings of bottom trawls and gillnets on the continental shelf in the Rio de Janeiro state, southeastern coast of Brazil. The ANCOVA did not indicate significant diferences in relative growth between sexes for both species (p > 0.05) while the length frequency was diferent (p < 0.001). Cynoscion guatucupa showed positive allometry, WT = 4E-06LT3.21 and C. jamaicensis negative allometry, WT = 2E-05LT2.90 (p < 0.05). Both species showed diferences in the condition factor between the sexes (p < 0.05). Significant diferences were observed in the measurements of the otoliths between the two species (p < 0.001). All regressions between fish measurements and otolith morphometry were highly significant (p < 0.001) for both species. The best estimates of fish size and weight were related to the otolith length: OL vs LT (r2 = 0.93; 0.96); OL vs LS (r2 = 0.92; 0.96); OL vs WT (r2 = 0.91; 0.93) for C. guatucupa and C. jamaicensis, respectively. This information adds useful biological data for multiple types of studies, e.g., food ecology (prey-predator), age and growth, reproduction, fisheries assessment and long-term landing monitoring. Our results confrmed the historical pattern of relative growth, supporting that otolith growth reflects the somatic growth of weakfishes in the study area, reinforcing the importance to determine these reference points.

Resumo O estuário do Rio Paraíba, maior e mais importante do estado da Paraíba, nordeste do Brasil, sofre intensa degradação ambiental pela população humana no seu entorno, e possivelmente várias espécies de peixes estão ameaçadas neste habitat. Nós apresentamos uma lista de espécies de peixes capturadas neste estuário, com base em espécimes tombados na coleção da Universidade Federal da Paraíba. Quatro ordens de Chondrichthyes e 26 ordens de Osteichthyes foram identificadas. Um total de 187 espécies de peixes foi registrado, incluindo oito espécies de Chondrichthyes e 179 Osteichthyes, com 123 gêneros e 57 famílias. Em relação à riqueza, Perciformes dominou com 32 espécies, seguido por Acanthuriformes e Clupeiformes. Comparando estuários ao longo do nordeste brasileiro e considerando nosso longo período de amostragens, seria esperada uma riqueza maior. De acordo com a lista vermelha da IUCN, Urotrygon microphthalmum é tida como Criticamente Ameaçada e mais sete espécies são classificadas como Vulnerável: Rhizoprionodon porosus, Rhinoptera bonasus, Megalops atlanticus, Epinephelus itajara, Hyporthodus niveatus, Lutjanus cyanopterus e Cynoscion acoupa. Três dessas espécies também aparecem na mesma categoria na lista brasileira de espécies ameaçadas, tendo todas elas, suas populações em declínio. Em relação aos Elasmobranchii, Carcharhinus porosus é listada como Criticamente Ameaçada em nosso país e globalmente. Esse inventário abrange e organiza o conhecimento acerca da comunidade de peixes que ocorre nesse importante ecossistema, com inferências sobre hábitos de vida, guildas ecológicas e status de conservação das espécies de peixes.

Abstract The Paraiba River estuary is the largest and most important estuary of Paraiba state, northeastern Brazil. It is under intense environmental degradation by the surrounding human population, and possibly several fish species are at risk in this habitat. Scientific sampling of the ichthyofauna started in the late 1970’s and proceeded until recently. We present a list of fish species captured in this estuary, based on voucher specimens housed at the Federal University of Paraiba collection. Four orders of Chondrichthyes and 26 orders of Osteichthyes were identified. A total of 187 fish species, including eight species of Chondrichthyes and 179 Osteichthyes, with 123 genera and 57 families were identified. Perciformes dominated in terms of richness (32 species), followed by Acanthuriformes and Clupeiformes. Comparing estuaries along the Brazilian northeastern coast and considering our large time sampling span, a higher richness would be expected. According to the IUCN Red List, Urotrygon microphthalmum is considered Critically Endangered and more seven species are classified as Vulnerable: Rhizoprionodon porosus, Rhinoptera bonasus, Megalops atlanticus, Epinephelus itajara, Hyporthodus niveatus, Lutjanus cyanopterus, and Cynoscion acoupa. Three of these species also appear in the same category in the threatened Brazilian list, all of which have declining population trends. Concerning the Elasmobranchii, Carcharhinus porosus is listed as Critically Endangered in our country and globally. This inventory organizes and broadens knowledge on the fish community that occurs in this important ecosystem, with inferences about life habits, ecological guilds and conservation status of the fish species.

Abstract The Franciscana dolphin is the most endangered cetacean in the Southwestern Atlantic Ocean. Knowing its biology and ecology is crucial to promote measures to prevent its bycatch, and the study of its diet contributes to the knowledge of its ecology. However, most of these studies are performed from hard remains found in stomach contents and these contents have different digestion and retention rates, which could lead to an overestimation of some prey. However, the analysis of undigested portions of the stomach content is implemented in marine predators whose diet consists in rapid digestion invertebrates. This method avoids the effect of digestion and accumulation of measurable hard remains. Consequently, an analysis of the P. blainvillei diet was performed in order to determine differences between both diet study methods, which allow to determine the effect of the differential digestion of prey and the accumulation of hard remains with taxonomic value. The study was conducted on 41 stomach contents, whose results showed great differences in the diet following both methods. Indigestible beaks of Loligo sanpaulensis and robust sagittal otoliths of Cynoscion guatucupa accumulate in the stomach, and thus, overestimate the importance of these prey. Moreover, the analysis evidence a rapid digestion of Engraulis anchoita and Trachurus lathami, which are underestimated. In turn, the results suggest changes in the characterization of trophic habits of P. blainvillei, in its nutrition, and in the degree of overlapping with the fisheries of the area. This latter one is crucial for the Franciscana dolphin because of the high accidental mortality rate in fishing nets.

Resumen El delfín franciscana (Pontoporia blainvillei) es el cetáceo más amenazado del Atlántico Sudoccidental. Conocer su biología es esencial para promover medidas medidas que permitan mitigar su captura incidental y estudiar su dieta, contribuye al conocimiento de su ecología. La mayoría de los estudios de dieta son realizados a partir de restos duros encontrados en contenidos estomacales con distintos grados de digestión y retención, llevando a sobrestimación o subestimación de presas. Sin embargo, el análisis de la fracción fresca del contenido estomacal es una metodología implementada en predadores marinos cuya dieta es dominada por invertebrados de rápida digestión, método independiente de los efectos de digestión y acumulación de restos duros cuantificables. Se realizó un análisis de dieta de Pontoporia blainvillei considerando por separado la fracción fresca y los restos duros, con el objetivo de determinar diferencias entre estos métodos que evidenciaran el efecto de la digestión diferencial y la acumulación de restos duros con valor taxonómico. El análisis de 41 contenidos estomacales, mostró diferencias entre ambos métodos de estudio, demostrando retención de mandíbulas de Loligo sanpaulensis, y otolitos sagitta de Cynoscion guatucupa, sobreestimando así su importancia; y una homogénea digestión de Engraulis anchoita . Trachurus lathami, subestimando su importancia. Este trabajo aporta evidencias de retención y digestión diferencial de presas que implican cambios en la caracterización de los hábitos tróficos de la especie, su nutrición y el grado de solapamiento con las pesquerías de la región. Siendo esto último importante en una especie con elevada tasa de mortalidad accidental en redes de pesca, como es el caso del delfín franciscana.

Abstract With the objective of evaluating the influence of the heat treatment on the chemical composition of fish refried with interesterified margarine, the white hake (Cynoscion leiarchus), fresh and braised forms, was determined its centesimal composition, calorific value and fatty acid profile. Cooking with interesterified margarine resulted in a reduction of 12% in protein content and 7.5% in ash content. The lipid content increased after frying (112%). As well as total saturated fatty acids (82.8%), monounsaturated fatty acids (858%) and polyunsaturated fatty acids (567%). There was a 33% reduction in total arachidonic and 48% in total DHA, in the braised hake with interesterified margarine in relation to fresh hake.

RESUMEN Introducción: Desde mediados del siglo XX el estuario del Golfo de Nicoya (10o N & 85o W) ha sido la fuente principal de numerosos recursos pesqueros, como los moluscos, crustáceos y peces. El estuario está actualmente bajo impactos crecientes locales, regionales y globales. Las expediciones a bordo de los buques científicos Skimmer (1979-1980) y Víctor Hensen (1993-1994) aportaron datos multidisciplinarios en apoyo de políticas de manejo. Sin embargo, actualmente se necesita información actualizada. Objetivos: Actualizar las listas publicadas de peces recolectados en ambas expediciones y sugerir nuevas áreas de investigación para una futura evaluación del estado del ecosistema. Métodos: En el buque Skimmer las capturas de peces cubrieron un ámbito de profundidad de 10 a 50 m, con una red tipo otter. En el buque V. Hensen las capturas se hicieron entre 10 y 240 m de profundidad, con redes tipo otter y beam. En ambos cruceros se hizo a bordo la identificación de las especies y la medición de sus longitudes totales. Para actualizar las listas de especies se procedió a la verificación de los nombres vigentes con base en literatura reciente y la página World Register of Marine Species (WORMS). Agregamos a la lista los nombres de las especies identificadas en años recientes para el estuario y catalogados en la Colección Ictiológica del Museo de Zoología, Universidad de Costa Rica. Resultados: El total de especies identificadas es de 268 para ambos buques. Una especie de Syacium está pendiente de identificación. Del total, 19 especies corresponden a peces cartilaginosos y 249 a peces óseos. Los Scianeidae (corvinas) y los lenguados estuvieron representados por 31 y 32 especies, respectivamente. El género Symphurus (lenguados) fue el más diverso, con 11 especies. Dieciocho especies fueron identificadas después de la publicación de las listas originales. Ocho especies fueron descritas con base en ejemplares recolectados por ambos buques: Gymnothorax phalarus, Notarius biffi, N. cookei, Ophicthus mecoptera, O. melope, Sphoeroides rosenblatti, Trinectes xanthurus y Urotrygon cimar. Las especies presentes en más del 50 % de las 20 estaciones del Skimmer, fueron: Prionotus horrens (16), Sphoeroides trichocephalus (14), Syacium ovale (13) y Synodus scituliceps (13). En las 12 estaciones del V. Hensen, fueron: Porichthys margaritatus (9), S. scituliceps (8), Bollmannia chlamydes (6), Symphurus callopterus (6), S. elongatus (6) y Synodus evermanni (6). Los cinco peces de mayor longitud capturados por ambos buques, fueron: la raya látigo Hypanus longus (117 cm), el congrio Cynoponticus coniceps (103 cm), el bagre Sciades dowii (87 cm), la raya Narcine brancroftii (80 cm) y la corvina reina Cynoscion albus (75 cm). La longitud total máxima promedio de 137 especies medidas en el Skimmer fue de 26 cm y de 29 cm para las 164 medidas en el V. Hensen. Conclusiones: En vista del incremento del número de usuarios de los recursos estuarinos, es urgente una evaluación multidisciplinaria del ecosistema en apoyo a la propuesta de nuevas políticas de manejo. Los resultados facilitarían actualizar el Modelo Trófico del Golfo de Nicoya, una herramienta de manejo disponible desde 1998 y basada principalmente en datos obtenidos durante los cruceros del Skimmer y V. Hensen. Tensores del ecosistema, como la extracción de recursos, el ingreso de contaminantes y su posible relación con la disrupción endocrina, así como la presencia de barreras naturales como la hipoxia en la boca del estuario, deben ser incluidos en esa futura evaluación.

Abstract Introduction: Since the middle of the XXth century the Gulf of Nicoya estuary (10o N & 85o W) has been the main source of numerous fishing resources, such as mollusks, crustaceans, and fish. The estuary is presently under the increasing impact of local, regional and global stressors. The expeditions on board the R.V. Skimmer (1979-1980) and R.V. Hensen (1993-1994) research vessels provided multidisciplinary data on the estuary in support of management policies. However, updated information is still needed. Objectives: To update the published lists of fish species from both expeditions and make suggestions for new research areas for future evaluations of the ecosystem. Methods: The fish collections by the Skimmer covered a depth range of 10 to 50 m using an otter trawl net, and those aboard the Victor Hensen were made between 10 and 228 m depth using otter and beam trawl nets. The identification of the fish species and the measurement of its lenghts were made on board of both vessels. The species names were updated based on recent literature and the web page World Register of Marine Species (WORMS). The list of species identified in recent years based on voucher specimens from the estuary and deposited in the Ichthyology Collection of the Museum of Zoology, University of Costa Rica, was also included. Results: The total number of identified species from both vessels is 268. A species of Syacium is yet undescribed. Of the total, 19 are cartilaginous fishes and 249 are bony fishes. The Sciaenidae and the flatfishes were represented by 31 and 32 species, respectivley. The flatfish genus Symphurus was the most diverse, with 11 species. Eighteen species were identified after the publication of the original lists. Eight species were described based on specimens collected during the expeditions: Gymnothorax phalarus, Notarius biffi, N. cookei, Ophicthus mecoptera, O. melope, Sphoeroides rosenblatti, Trinectes xanthurus and Urotrygon cimar. The species present in more than 50% of the 20 Skimmer stations, were: Prionotus horrens (16 stations), Sphoeroides trichocephalus (14), Syacium ovale (13) and Synodus scituliceps (13). In the 12 stations of the V. Hensen there were: Porichthys margaritatus (9), S. scituliceps (8), Bollmannia chlamydes (6), Symphurus callopterus (6), S. elongatus (6), and Synodus evermanni (6). The five longer specimens collected by both vessels, were: the longtail sting ray Hypanus longus (117 cm), the pike conger Cynoponticus coniceps (103 cm), the brown sea catfish Sciades dowii (87 cm), the electric ray Narcine brancroftii (80 cm), and the queen corvina Cynoscion albus (75 cm). The average total length for 137 species measured during the Skimmer cruises was 26 cm, and 29 cm for the 164 measured during the V. Hensen survey. Conclusions: In view of the increasing number of users of the estuarine resources, it is urgent a multidisciplinary evaluation of the ecosystem in support of new management policies. The expected results may facilitate updating the Gulf of Nicoya Trophic Model, a management tool available for the estuary since 1998 and based mainly on information gathered during both expeditions. Ecosystem stressors, such as the extraction of resources, the input of pollutants and its possible link to endocrine disruption, as well as the presence of natural barriers such as hypoxia at deeper waters at the mouth of the estuary must be taken into account in a future evaluation.

RESUMO Apesar de sua importância em termos biogeográficos, ecológicos e comerciais, a ictiofauna da costa norte do Brasil ainda é pouco conhecida, representando a porção menos amostrada da Zona Econômica Exclusiva Brasileira. Durante extensivo esforço de inventário na costa norte do Brasil, nós obtivemos uma série de espécimes de Cynoscion similis e concluímos que a espécie é comum nesta região. Embora a espécie não tenha sido relatada anteriormente para o estado do Pará, ela pode ter sido registrada em estudos sobre a pesca industrial, sendo identificada apenas como Cynoscion sp. ou pelo nome comum pescada negra. Isso reforça a necessidade de identificação taxonômica confiável de espécies, com objetivo de garantir dados precisos de ecologia e pesca, e apoiar o desenvolvimento de estratégias efetivas de conservação. Aqui, nós fornecemos novos dados morfológicos e moleculares importantes para a diferenciação de Cynoscion similis e C. jamaicensis, a espécie mais próxima morfologicamente, assim como de outros congêneres.

ABSTRACT Despite its importance in biogeographical, ecological, and commercial terms, the fish fauna of the northern Brazilian coast is still poorly known, representing the least sampled portion of the Brazilian Exclusive Economic Zone. We collected Tonkin weakfish, Cynoscion similis specimens during extensive surveys of the northern Brazilian coast and concluded that C. similis is common in this region. While the species had not previously been reported for the northern Brazilian state of Pará, it may have been recorded in studies of industrial fisheries, being identified only as Cynoscion sp. or by the common name pescada negra. This reinforces the need for the reliable taxonomical identification of species, to guarantee the collection of accurate data on ecology and fisheries, and ultimately, support the development of effective conservation strategies. Here we provide additional morphological and molecular data to distinguish Cynoscion similis from the closely related Cynoscion jamaicensis, and other congeners.

Resumo O objetivo deste estudo foi analisar a composição isotópica no músculo de Cynoscion guatucupa no Oceano Atlântico Sul Ocidental, a fim de avaliar uma possível variação de δ13C e δ15N como resposta às mudanças ontogenéticas na dieta. Foram também exploradas evidências isotópicas de diferenças entre os locais de amostragem. Os resultados mostraram uma concordância entre a análise de isótopos e os estudos convencionais prévios. Diferenças na composição isotópica entre locais de amostragem não foram observadas. Uma relação positiva existe entre valores isotópicos e comprimento total dos animais. A análise de cluster definiu três grupos de classes de tamanho, validados pelo MDS. Foram também observadas, através de modelos isotópicos mistos (SIAR), diferenças no consumo relativo de espécies de presas para cada classe de tamanho. Variações em δ15N entre as classes de tamanho estariam associadas ao consumo de diferentes tipos de presas ao longo do crescimento dos animais. Indivíduos pequenos alimentam-se de pequenos crustáceos e progressivamente aumentam seu consumo de peixes (Engraulis anchoita), aumentando assim os seus valores isotópicos. Por outro lado, as diferenças nos valores de δ13C parecem estar relacionadas com variações no padrão de distribuição espacial específico de cada classe idade. Desta maneira, tanto C. guatucupa grandes como pequenos permanecem especializados, porém alimentando-se de presas diferentes, em diferentes níveis tróficos e em diferentes áreas. Estes resultados contribuem para o estudo da dieta de C. guatucupa, melhoram os modelos de ecologia isotópica e ressaltam a importância de se considerar a variação na composição isotópica na resposta às mudanças de dieta relacionadas ao tamanho de um dos principais recursos pesqueiros da região.

Abstract The aim of this study was to analyze the isotopic composition in muscle of striped weakfish Cynoscion guatucupa from Southwest Atlantic Ocean in order to evaluate a possible variation in δ13C and δ15N in response to dietary shifts that occur as animals grow. We also explored for isotopic evidence of differences between sample locations. The results showed an agreement between isotope analysis and previous conventional studies. Differences in the isotope composition between sampling location were not observed. A positive relation exists between isotope values and total body length of the animals. The Cluster analysis defined three groups of size classes, validated by the MDS. Differences in the relative consumption of prey species in each size class were also observed performing isotope mixing models (SIAR). Variation in δ15N among size classes would be associated with the consumption of a different type of prey as animals grow. Small striped weakfish feed on small crustaceans and progressively increase their consumption of fish (anchovy, Engraulis anchoita), increasing by this way their isotope values. On the other hand, differences in δ13C values seemed to be related to age-class specific spatial distribution patterns. Therefore, large and small striped weakfish remain specialized but feeding on different prey at different trophic levels. These results contribute to the study of the diet of striped weakfish, improve the isotopic ecology models and highlight on the importance of accounting for variation in the isotopic composition in response to dietary shifts with the size of one of the most important fishery resources in the region.

Abstract: The Upper Gulf of California and Colorado River Delta is a zone which is immersed in an ecological, economic, political and social conflict. That is because of the Totoaba Totoaba macdonaldi illegal fishing and the Vaquita Phocoena sinus potential extinction. This issue has driven to ban all the region's fisheries with the exception of the Gulf corvina Cynoscion othonopterus which is the only of the finfish species with operating license. Therefore, the main objetive was to evaluate the fishery's health condition through the Froese sustainability indicators in Upper Gulf of California during 2008, 2013, 2014 and 2015 fishing seasons. The results showed that the Gulf corvina annual production ratio showed fluctuations, highlighting in the 2012-2016 period, when the whole fishing captures with the exception of 2014, surpassed the established quota by the National Institute of Fishery (Instituto Nacional de Pesca). The size-at-maturity were: 2008= L50: 502 mm (IC= 490-514 mm), 2013= L50: 559 mm (IC= 544-576 mm), 2014= L50: 499 mm (IC= 476-518 mm), and 2015= L50: 480 mm (IC= 445-510 mm). Based on the sustainability indicators, it is demonstrated that the Gulf corvina fishery is directed towards the organisms of greater length (mega-spawners). Finally it is concluded that Gulf corvina currently shows problems of over-exploitation and therefore its exploitation is not sustainable. This suggests the need to make adjustments and updates to current management measures.

Resumen: El Alto Golfo de California y Delta del Río Colorado es un área que se encuentra inmersa en un conflicto ecológico, económico, político y social debido a la pesca ilegal de totoaba Totoaba macdonaldi y la posible extinción de vaquita marina Phocoena sinus. Esto último ha provocado el cierre de todas las pesquerías en la región salvo la de curvina golfina Cynoscion othonopterus la cual es la única especie con permiso de explotación. Por lo tanto, el objetivo principal fue evaluar el estado de salud de la pesquería mediante los indicadores de sustentabilidad de Froese en el Alto Golfo de California durante las temporadas de pesca 2008, 2013, 2014 y 2015. Los resultados mostraron que la producción anual de curvina golfina presenta fluctuaciones, resaltando el periodo 2012-2016, donde las capturas totales con excepción de 2014, sobrepasaron la cuota de captura establecida por el Instituto Nacional de la Pesca. La longitud de madurez para los años estudiados fueron: 2008= L50: 502 mm (IC= 490-514 mm), 2013= L50: 559 mm (IC= 544-576 mm), 2014= L50: 499 mm (IC= 476-518 mm), y 2015= L50: 480 mm (IC= 445-510 mm). Con base en los indicadores de sustentabilidad, se demuestra que la pesquería de curvina golfina está dirigida hacia los organismos de mayor longitud (mega-reproductores). Se concluye que actualmente la curvina golfina manifiesta problemas de sobreexplotación y por ende su aprovechamiento no es sustentable. Esto sugiere la necesidad realizar ajustes y actualizaciones a las actuales medidas de manejo.

ABSTRACT Small-scale fisheries in Brazil contribute to a significant share of total fish production, accessing a large variety of species. Life history parameters from these resources are important for their management and conservation, based on primary data. The objective of this article is to generate growth parameters and mortality rates of ten fish populations from a coastal zone in Southeastern Brazil. Monthly samples were taken between January 2011 and November 2014 from landings of the beach-seine fishery in an area adjacent to the entrance of the Guanabara Bay. All fishes were measured (total length) and weighed. The length-weight relationships (LWR) were estimated by linear regression analysis on log-transformed data of the equation: W = aL b . The Von Bertalanffy Growth Function (VBGF) was fitted to size-at-age data to obtain growth parameters (K, L ∞ ). The length-converted catch curve was used for estimating the instantaneous total mortality (Z). Taylor’s equations provided an independent estimate of the natural mortality (M) and longevity. The difference between Z and M derived Fishing mortality (F). A total of 2,938 individuals from ten fish species were used to determine the length-weight relationships. Harengula clupeola (Cuvier, 1829) has a new maximum length record for the FishBase LWR database. Sardinella brasiliensis (Steindachner, 1879) presented the smallest and largest size recorded for LWR observed in the literature and FishBase database. Upeneus parvus showed the greatest total length, while Trichiurus lepturus Linnaeus, 1758, Orthopristis ruber (Cuvier, 1830) and Dactylopterus volitans (Linnaeus, 1758) presented the smallest sizes for LWR in FishBase. The other species showed parameters within the expected values for each group. The performance index combining information from K and L ∞ presented values between 2.32 and 3.76 and were considered appropriate for the populations evaluated. Fishing was the primary source of mortality for Caranx crysos (Mitchill, 1815), Eucinostomus argenteus Baird & Girard, 1855, S. brasiliensis and U. parvus, and less important for Cynoscion jamaicensis (Vaillant & Bocourt, 1883), D. volitans, O. ruber, Selene setapinnis (Mitchill, 1815), T. lepturus and H. clupeola. The parameters generated may be used for the management and conservation of the species’ stocks.

The surf zone of sandy beaches exhibits high faunal diversity and can be a nursery habitat for fish and crustacean. Croakers (Cynoscion spp.) are commercially and ecologically important euryhaline fishes whose larvae are found in the surf zone of sandy beaches; however, little is known about their biology. In this project, the use of surf zones was determined by studying the presence, density and growth of croaker larvae in an Ecuadorian surf zone adjacent to the largest estuarine system of western South America, and the relationship of these three factors with environmental variables explored. Fish larvae were collected during three days in the rainy season, using a hyperbenthic sledge and their otoliths analyzed. Croakers accounted for 58.6% of all larvae collected (mean density = 8.97 ± 10.17 ind 100 m-2). Size frequency distribution analysis (2.3 to 7.9 mm standard length, SL) resulted in a multimodal distribution, suggesting there were several cohorts of larvae that entered the surf zone and some inhabited the surf zone for several days. Recent larval growth rate (last three days) was 0.42 ± 0.12% SL day-1 and was positively related to water temperature, oxygen and croaker density, suggesting the number of croakers in the surf zone increased as growth conditions improved. Our study suggests that croaker larvae are the primary users of Ecuadorian surf zones adjacent to estuarine systems during the wet season, where they enter by pulses, attracted by better conditions for growth.

La zona de rompiente de playas arenosas presenta una alta diversidad faunística y es criadero para peces y crustáceos. Las corvinas (Cynoscion spp.) son peces eurihalinos de importancia comercial y ecológica cuyas larvas usan las zonas de rompiente, sin embargo su biología es poco conocida. Se determinó el uso de zonas de rompiente estudiando la presencia, densidad y crecimiento de larvas de corvina en una playa arenosa ecuatoriana adyacente al sistema estuarino más grande del oeste de Sudamérica y se exploró las relaciones de estos tres factores con las variables ambientales analizadas. Se colectaron larvas de peces durante tres fechas en época húmeda, utilizando un trineo hiperbentónico y se analizaron sus otolitos. Las corvinas representaron el 58,6% de las larvas colectadas (densidad media = 8,97 ± 10,17 ind 100 m-2). El análisis de frecuencias de longitudes (2,3 a 7,9 mm longitud estándar, LE) determinó una distribución multimodal, sugiriendo que hubo varias cohortes de larvas que ingresaron a la playa habitándola durante varios días. La tasa de crecimiento reciente (últimos tres días) fue de 0,42 ± 0,12% mm LE día-1 y estuvo relacionada positivamente con la temperatura, oxígeno disuelto y densidades de corvina, sugiriendo que el número de corvinas en la zona de rompiente aumentó a medida que mejoran las condiciones para su crecimiento. Este estudio sugiere que las larvas de corvinas son las principales usuarias de la zona de rompiente de playas arenosas cercanas a desembocadura de ríos durante la época húmeda, donde ingresan por pulsos, atraídas por condiciones favorables para su crecimiento.

ResumenLas corvinas son especies de interés comercial que han sido sobreexplotadas en el Golfo de Nicoya, Costa Rica. El objetivo de este estudio fue describir por primera vez, el desove espontáneo y la ontogenia de las larvas de la corvina aguada Cynoscion squamipinnis en cautiverio, con el fin de realizar repoblamiento y proyectos de maricultura. Reproductores silvestres (n= 6, 1-2 Kg), fueron capturados y mantenidos en la Estación de Biología Marina Juan Bertoglia Richards (Puntarenas, Costa Rica) por un periodo de dos años (octubre 2006-diciembre 2008). Durante este periodo, el estado de madurez de las hembras (n= 3) fue registrado mediante muestras de cánula y los machos (n= 3) mediante masaje abdominal. Todos los reproductores fueron colocados juntos en un tanque de 18 t, con aireación, a una salinidad entre 33-35 ups y expuestos a una temperatura constante (29 ± 1 °C). De enero a marzo 2009 ocurrió un periodo de desove espontáneo, obteniéndose 162 000 huevos en tres desoves. El porcentaje de fertilización fue de 50-60 %, y la supervivencia después de la eclosión fue entre 60-85 %. El diámetro de los huevos fue de 0.852 mm (Desviación Estándar= 0.039), con una gota de aceite de 0.269 mm (DE= 0.016). En el desarrollo embrionario, la primera división mitótica ocurrió una hora después del desove (hdd), la segunda división 1:30 hdd, la tercera división 2 hdd, la cuarta división a las 2:30 hdd, y la quinta 3:00 hdd. La mórula fue observada a las 3:30 hdd, la blástula a las 4:30 hdd, la gástrula a las 8:30 hdd, la forma C a las 10:00 hdd, y la forma S ocurrió de las 10-19 hdd. La eclosión ocurrió 19 hdd. La larva midió 2.234 mm (DE= 0.122) de longitud total (LT), y 2.179 mm (DE= 0.119) de longitud notocordial (LN). La preflexión inició 49 hdd, la flexión 11 días después del desove (ddd) (3.767 mm LT, DE= 0.209), y la postflexión a los 14 ddd (4.015 mm LT, DE= 0.302). A los 45 ddd, los juveniles pesaron 3.68 g (DE= 1.09). El tiempo de eclosión de las larvas de la corvina aguada fue menor al de otras especies de corvina. Los tiempos de formación en las etapas embrionarias difirieron poco con respecto a los tiempos observados para otras especies de corvinas. Las diferencias observadas con respecto a otras especies, probablemente responden a las características genéticas propias de cada especie y a la temperatura de incubación de los huevos. La obtención de desoves espontáneos sin aplicaciones hormonales a los reproductores, y la producción de juveniles en cautiverio demostraron que la corvina aguada puede ser considerada en programas de repoblamiento y proyectos de maricultura.

Abstract:The croakers or drums are commercial species, which have been overfished in the Nicoya Gulf, Costa Rica. This study aimed to describe, for the first time, the reproduction and the ontogeny of weakfish, Cynoscion squamipinnis in captivity, in order to perform restocking and mariculture projects. Wild fish (n= 6, 1-2 Kg) were captured and maintained in the Estación de Biología Marina Juan Bertoglia Richards (Puntarenas, Costa Rica) for a two years period (October 2006- December 2008). During this period, maturation stage was monitored periodically by cannula samples in the females (n= 3) and gentle massage in males (n= 3). All fish were stocked in an 18 t tank, with aeration, 33-35 ups of salinity, and a constant temperature (29 ± 1 °C). The spawning period occurred from January to March 2009, producing 162 000 eggs in three spontaneous spawns. The fertilization percentage was 50-60%, and survival after hatching was 60-85%. The egg diameter was 0.852 mm (Standard deviation (SD)= 0.039), and oil drop of 0.269 mm (SD= 0.016). In the embryonary development, the first mitotic division (MD) was observed one hour after spawning (has), the second MD was 1:30 has, the third MD was 2:00 has, the fourth MD was 2:30 has, and fifth MD at 3:00 has. Morule was observed 3:30 has, the blastule 4:30 has, the gastrule 8:30 has, C shape at 10:00 has, and C shape at 12:00 has. After 19 has hatching larvae occurred. The total length (TL) of the larvae was 2.234 mm (SD= 0.122), and the nothochordial length (NL) was 2.179 mm (SD= 0.119). Preflexion stage was observed 49 has, flexion stage was 11 days after spawn (das) (3.767 mm LT (SD= 0.209)), and postflexion stage was 14 das (4.015 mm LT (SD= 0.302)). After 45 das, the juvenile weights 3.68 g (SD= 1.09). Hatch time of the weakfish larvae was minor than of others croaker species. The stages times of embrionary development were a little different from others croaker species, and probably respond to genetic characteristics of each species and the eggs incubation temperature. The spontaneously spawning without broodstock hormonal applications, and the juveniles production in captivity showed that weakfish is a potential species for restocking programs and mariculture projects. Rev. Biol. Trop. 64 (3): 991-1005. Epub 2016 September 01.

Isabel Island is a National Park located in the northwest Mexico with an unprotected marine area, where the small-scale fishing is allowed. The impact of this activity in the ecosystem and exploited biological resources has not been evaluated. From May 2013 to April 2014 the fishing grounds of Isabel Island were monthly monitored. The most widely used fishing gears were the gillnet (96.4%), hook-and-line (2.1%) and long-line (1.5%). A total 2,388 specimens were caught, corresponding to 19 families, 33 genera, and 46 species. The most frequent species caught were Lutjanus peru (%IRI = 55.34), L. guttatus (%IRI = 16.01), L. argentiventris (%IRI = 11.53), Cynoscion reticulatus (%IRI = 3.23) and Hoplopagrus guentherii (%IRI = 3.02), representing 89.13% of the total catch. The diversity was low (H' = 2.01), dominated by few species (J' = 0.52), mainly snappers (Lutjanidae).

La Isla Isabel es un Parque Nacional localizado en el noroeste de México, cuya área marina no está protegida y la pesca artesanal está permitida, aunque los impactos de esta actividad sobre el ecosistema y los recursos naturales explotados no han sido evaluados. De mayo 2013 a abril 2014 se monitoreó mensualmente diferentes campos pesqueros de la Isla Isabel. Los artes de pesca más utilizados fueron la red de enmalle (96,4%), la línea de mano (2,1%) y la cimbra (1,5%), capturándose 2.388 ejemplares pertenecientes a 19 familias, 33 géneros y 46 especies. Las especies mejor representadas en las capturas fueron Lutjanus peru (%IIR = 55,34), L. guttatus (%IIR = 16,01), L. argentiventris (%IIR = 11,53), Cynoscion reticulatus (%IIR = 3,23) y Hoplopagrus guentherii (%IIR = 3,02), representando 89,13% de la captura total. La diversidad fue baja (H' = 2,01), dominada por pocas especies (J' = 0,52), principalmente pargos (Lutjanidae).

The present study analyses the seasonal (summer: January, February, March; autumn: April, May, June; winter: July, August, September and spring: October, November, December) and annual (2006, 2007 and 2011) length-weight relationships and condition factors of Micropogonias furnieri and Cynoscion guatucupa from Río de la Plata and the Uruguayan ocean coast from data collected throught monthly landings by the Uruguayan coastal fleet in the Montevideo port (Uruguay). A total of 9,146 individuals of M. furnieri ranging from 15 to 69 cm total length (L T); and 5,285 individuals of C. guatucupa, ranging from 21 to 54 cm L T were analyzed. For both species, the allometry coefficients showed that growth in the majority of seasons were negative (b < 3), except for M. furnieri in spring 2006 (isometric, b = 3) and during summer 2011 (positive, b > 3). For M. furnieri, no significant differences among slopes were found between 2006 and 2007 whereas 2011 showed significant differences compared to 2006 and 2007. For C. guatucupa no significant differences among slopes were found between 2007 and 2011, whereas 2006 showed significant differences with other years. The highest values for the condition factor in M. furnieri were recorded in summer 2006, and during the summer and autumn 2007 and for C. guatucupa in winter 2006 and autumn 2007. Significant seasonal and annual differences for condition factors were found for both species. This work provides the first reference regarding condition factor for both sciaenid species in the study area.

RESUMEN En este trabajo se analizaron las relaciones longitud-peso y el factor de condición de Micropogonias furnieri y Cynoscion guatucupa en diferentes épocas [verano; otoño; invierno, primavera y años (2006, 2007 y 2011)] a partir de muestreos mensuales de desembarques de la flota costera uruguaya que operó en el Río de la Plata y costa oceánica uruguaya. Fueron analizados 9.146 individuos de M. furnieri (entre 15-69 cm de longitud total) y 5.285 individuos de C. guatucupa, (entre 21-54 cm de longitud total). Para ambas especies, el coeficiente de alometría fue negativo (b < 3), excepto para M. furnieri en primavera de 2006 (isométrico, b = 3) y durante verano de 2011 (positivo, b > 3). Para M. furnieri, las pendientes no mostraron diferencias significativas entre el 2006 y 2007, mientras que el 2011 presentó diferencias significativas con ambos años. Para C. guatucupa no se encontraron diferencias significativas entre el 2007 y 2011, pero si cuando ambos años fueron comparados con el 2006. Los mayores valores del factor de condición fueron obtenidos en verano de 2006 y durante el verano y otoño del 2007 para M. furnieri, mientras que para C. guatucupa fueron en invierno 2006 y otoño 2007. Para ambas especies el factor de condición mostró diferencias significativas estacionales y anuales. Este trabajo presenta la primera referencia del factor de condición para estas especies de Sciaenidos en el área de estudio.

ABSTRACT Cynoscion leiarchus (Cuvier, 1830) is a coastal fish species that is widely distributed along the Western Atlantic coast, from Belize to Southern Brazil. In Brazil, C. leiarchus It is an important resource for commercial and artisanal fisheries. Our objective was to describe the oogenesis and spermatogenesis stages of the species and to estimate batch size and relative fecundity of a population at a tropical bay in southeastern Brazil. The examined specimens were obtained from artisanal catches that took place from July 2013 to June 2014. A total of 18 individuals (11 females and 7 males) were examined for histological analysis and 20 spawning-capable females were used to estimate fecundity. Five stages of oocyte development (primary growth, pre-vitellogenic, vitellogenic, oocyte maturation and atresia) and four stages of spermatocytes (spermatogonia, spermatocytes, spermatids, spermatozoa) were described in different phases of gonad development (immature, developing, spawning capable and regenerating), suggesting that spawning happens in batches, oocyte development is asynchronic and fecundity is indeterminate. Batch fecundity ranged from 100 × 103 to 866 × 103 oocytes undergoing final oocyte maturation, and relative fecundity ranged from 232 to 1,225 oocytes, averaging 467 oocytes per gram of ovary-free body weight. Fecundity tended to increase linearly with gonadal weight, total weight, total length, and age, but the highest linear correlation obtained was between fecundity and gonadal weight. This study provides the first information on the gonadal development of C. leiarchus from the Brazilian coast and is a baseline to compare with other populations and/or congeneric species.