ABSTRACT Atlantoraja cyclophora is an endemic skate to the continental shelf of the Southwestern Atlantic Ocean (22ºS-47ºS) and a by-catch species in commercial bottom trawl fisheries. The morphometric relationships, the size at maturity and the reproductive cycle of this species were analyzed, with samples collected between 34ºS and 42ºS. The size range was 190 to 674 mm total length (TL) for males and 135 to 709 mm TL for females. Sexual dimorphism between the relationships TL - disc width and TL - total weight was found, with females wider and heavier than males. The mean size at maturity for males was estimated in 530 mm TL and for females in 570 mm TL. The gonadosomatic index (GSI) in mature females varied seasonally and showed the highest value in December. The maximum follicular diameter and oviductal gland width did not show any seasonal pattern. Females with eggs in the uterus were present most of the year. The reproductive activity in males would be continuous throughout the year, evidenced by the lack of variation in the GSI between seasons. The results obtained suggest that A. cyclophora might undergo an annual reproductive cycle, in coincidence to that reported for this species in Brazilian populations.

RESUMEN Atlantoraja cyclophora es una raya endémica de las plataformas continentales del Océano Atlántico Sudoccidental (22ºS-47ºS) que se captura incidentalmente en las pesquerías comerciales de arrastre de fondo. Se estudiaron las relaciones morfométricas, el ciclo reproductivo y se estimó la longitud media de madurez sexual de esta especie con muestras colectadas entre 34ºS y 42ºS. El rango de tamaño fue 190 a 674 mm de longitud total (LT) en machos y 135 a 709 mm LT en hembras. Se observó dimorfismo sexual entre las relaciones LT - ancho de disco y LT - peso total, siendo las hembras más anchas y pesadas que los machos. La talla de madurez se estimó en 530 mm LT para machos y en 570 mm LT para hembras. El índice gonadosomático (IGS) en hembras maduras varió estacionalmente, con el valor más alto en Diciembre. No se registró variación estacional respecto al diámetro máximo folicular y al ancho de la glándula oviductal. Se observaron hembras con huevos en los úteros durante la mayor parte del año. La actividad reproductiva en los machos sería continua durante todo el año, dada la falta de variación del IGS entre estaciones. Se sugiere que A. cyclophora experimenta un ciclo reproductivo anual, similar a lo reportado para esta especie en aguas de Brasil.

ABSTRACT The reproductive potential of red porgy in coastal waters of Buenos Aires Province (Argentina) and Uruguay (34º-39ºS) was studied by means of a macroscopic and histological analysis of the gonads. Length and age at first maturity were determined, and fecundity, spawning frequency and egg quality were estimated. The spawning season extended from spring through summer between October and January with a peak of spawning in December. Length and age at maturity for sexes combined was 24.5 cm TL and 1.54 years, respectively. Batch fecundity ranged from 6,974 (25 cm TL) to 110,725 (39 cm TL) hydrated oocytes and showed significant linear relationships with total length and ovary-free weight. Relative fecundity ranged from 16 to 172 oocytes per female gram (ovary free). Spawning frequency was 58.5% during January 2011, indicating that females spawned once every 1-2 days at the peak of the spawning season. The life history of red porgy in Argentina and Uruguay was characterized by a young age at first maturity and partial, almost daily, spawning in a bounded time period, a life history strategy that would facilitate population expansion or colonization of new areas, and high population recovery rates or growth (r).

RESUMEN Se analizó el potencial reproductivo del besugo en aguas costeras de la provincia de Buenos Aires (Argentina) y Uruguay sobre la base del análisis macroscópico e histológico de las gónadas. Se determinó la talla y edad de primera madurez sexual y se estimaron la fecundidad, frecuencia de puesta y calidad ovocitaria. Se pudo establecer que la actividad reproductiva del besugo acontece durante primavera-verano, entre octubre y enero, con un pico de desove principal en diciembre. La estimación de la talla y edad de primera madurez para ambos sexos fue de 24,5 cm LT y 1,54 años respectivamente. La fecundidad parcial presentó un ajuste lineal con la talla y el peso de la hembra y varió entre 6.974 (25 cm LT) y 110.725 (39 cm LT) ovocitos hidratados. La fecundidad relativa osciló entre 16 y 172 ovocitos hidratados g-1. Los valores de ambos parámetros presentaron diferencias interanuales. La frecuencia reproductiva, determinada mediante el uso de los porcentajes de hembras con folículos post ovulatorios, fue de 58,5% durante enero de 2011, lo que indica que los desoves ocurren una vez cada 1-2 días. Los resultados hallados indican que el besugo se caracteriza por presentar una edad de primera madurez baja (entre 1 y 2 años), desoves parciales casi diarios pero en un período de tiempo acotado. Este tipo de estrategia podría explicar tasas de recuperación o de crecimiento poblacional (r) altas como así también la ampliación de su área de distribución o la colonización de nuevas áreas.

ABSTRACT Pinguipes brasilianus is a conspicuous and abundant rocky-reef fish inhabiting the Northern Patagonian gulfs of Argentina, Southwest Atlantic. This study describes its reproductive biology in this region. We made macroscopic and histological descriptions of the testis and ovary development, analyzed the evolution of the gonadosomatic index (GSI) in both sexes throughout the year, and estimated fecundity and length at 50% maturity for females. Pinguipes brasilianus is a multiple spawner with indeterminate annual fecundity and an extended reproductive season, encompassing austral spring and summer. Low GSI values in males (monthly means ranged between 0.11% and 0.75%) and low relative fecundity in female fish (between 2 and 44 oocytes/g) are consistent with a need of close proximity between male and female during oocyte fertilization, sexual courtship and with spawning in pairs and/or within reef crevices. The estimated length at 50% maturity (± SD) for females was 15.22 ± 0.43 cm total length. Although P. brasilianus shares the main reproductive features of its congeneric species Pinguipes chilensis , male GSI and female length at 50% maturity in P. brasilianus were markedly lower than those reported for P. chilensis , while relative and batch fecundity were greater in fish of the same size.

RESUMEN Pinguipes brasilianus es una especie abundante en los arrecifes rocosos de los golfos norpatagónicos de Argentina, en el Atlántico Sudoccidental. En este trabajo estudiamos su biología reproductiva, incluyendo la descripción macroscópica e histológica del desarrollo de testículos y ovarios, el análisis de la evolución del índice gonadosomático (IGS) para ambos sexos a lo largo del ciclo anual, y la estimación de la fecundidad y la talla de primera madurez para las hembras. Pinguipes brasilianus es un desovante múltiple con fecundidad indeterminada y una estación reproductiva extensa que abarca la primavera y el verano australes. Los bajos valores de IGS en machos (el promedio mensual varió entre 0,11% y 0,75%), y la baja fecundidad relativa en las hembras (entre 2 y 4 oocitos/g) son consistentes con un sistema de apareamiento que involucra una estrecha proximidad entre machos y hembras durante la fertilización de los oocitos, cortejo y desove en parejas y/o en áreas confinadas (ej .: refugios). La talla de primera madurez (± DE) estimada para las hembras fue de 15,22 ± 0,43 cm de largo total. Aunque P. brasilianus comparte los principales rasgos reproductivos con Pinguipes chilensis , tanto los valores promedio de IGS en machos como la talla de primera madurez en hembras fueron menores que los reportados para P. chilensis , mientras que la fecundidad (parcial y relativa) fue mayor.

Percophis brasiliensis é uma espécie demersal que constitui um recurso importante para a pesca costeira na Argentina. Não obstante, a informação sobre a dinâmica bioenergética da reprodução não tem sido reportada. Assim, as variações sazonais dos fatores de condição, composição bioquímica e densidade de energia de diferentes tecidos foram analisados para determinar a estratégia de alocação de energia durante o ciclo reprodutivo da espécie. Os índices de condição (hepatossomático e K) mostraram um padrão sazonal oposto ao observado para o índice gonadossomático, o qual foi caracterizado por valores mais elevados durante o período reprodutivo (primavera-verão), diminuindo no final da desova. A composição bioquímica de diferentes tecidos também mostrou uma sazonalidade claramente associada ao ciclo reprodutivo. Análise da densidade de energia do fígado indica que P. brasiliensis acumula energia no inverno, antes da reprodução, que mais tarde decresce durante a época de desova. Em contraste, a densidade de energia no músculo não mostrou diferenças significativas entre as estações do ano, indicando que os indivíduos poderiam ter também uma fonte externa de energia durante a reprodução. Portanto, é possível que P. brasiliensis responda a uma combinação das estratégias "capital breeder" (armazenam a energia antes do início da atividade reprodutiva) e "income breeder" (adquirem energia através da alimentação ativa durante o período de desova).

Percophis brasiliensis is a demersal species that constitutes an important resource of Argentine coastal fisheries. Nevertheless, information about bioenergetic dynamic of reproduction has not been reported. Therefore, seasonal variations of condition factors, biochemical composition and energy density of different tissues were analyzed in order to determine the strategy of energy allocation during the reproductive cycle of this species. Condition indices (hepatosomatic and K) showed a seasonal pattern opposite to that observed for gonadosomatic index, which was characterized by higher values during the reproductive period (spring-summer), decreasing at the end of spawning. Biochemical composition of different tissues also showed a clearly seasonality associated to reproductive cycle. Analysis of energy density variation of liver indicates that P. brasiliensis accumulate reserves in winter before reproduction, which later decrease during the spawning season. In contrast, the energy density in muscle did not show significant differences among seasons, indicating that individuals could be also using an external source of energy during spawning. Therefore, it is possible that P. brasiliensis respond to an intermediate strategy of energy allocation, combining characteristics of both capital breeders (stores energy previous to the onset of reproductive activity) and income breeders (acquire energy by active feeding during spawning period).

A composição e distribuição dos glicoconjugados (GCs) secretado pelo epitélio do ovário de lamelas com referência à biologia reprodutiva de Genypterus blacodes (Schneider, 1801) através da histoquímica com lectinas é aqui discutida. Nesta espécie, as células epiteliais que revestem a cavidade do ovário apresentou acentuada variação morfológica ao longo do ciclo reprodutivo relacionados com a secreção de muco que acompanha a maturação do oócito. Durante a época de desova, de resíduos de manose e N-acetilglicosamina foram detectados no glicocálix dessas células usando histoquímica de lectinas. N-acetilgalactosamina e fucose também foram observados na mesma zona. As maiores variações no padrão de lectinas foram encontradas na composição do citoplasma apical, em comparação com a zona basal das células. Os resultados do presente estudo foram discutidos, comparando as suas possíveis implicações funcionais.

The composition and distribution of the glycoconjugates (GCs) secreted by the epithelium of ovarian lamellae with reference to the reproductive biology of Genypterus blacodes (Schneider, 1801) through lectin hi stochemistry is here discussed. In this species, the epithelial cells that line the ovarian cavity presented sharp morphological variations along the reproductive cycle related to the mucus secretion that accompanies oocyte ma turation. During sp awning season, residues of mannose and N-acetylglucosamine were detected in the glycocalyx of those cells using lectinhistochemistry. N- acetylgalactosamine and fucose were also observed in the same zone. The greatest variations in the lectinhistochemical pattern were found in the apical cytoplasm composition in comparison to the basal zone of the cells. The results of the present study were discussed by comparing their possible functional implications.

Diverse indices have been used to characterize the nutritional condition of fish larvae. Histological criteria were shown to be reliable in diagnosing nutritional condition, because they involve the study of cellular aspect, structure and tissular integrity. However, since the microscopical appearance of larval tissues varies both as a consequence of nutritional status and developmental stages, it becomes necessary to characterize the employed structures and to take into account the developmental stage of the studied specimen. The aim of this study was to develop a typical micro-anatomical description to assess the nutritional condition of Engraulis anchoita fish larvae collected in the Argentine Sea. Several tissues were diagnosed to calculate a histological condition index (ICH) in regards to anchovy larvae ontogeny. In addition, the tissues analysed were divided into short and long-term indices. A reduction of HCI was observed during yolk exhaustion and at the end of the larval stage. In order to detect slight changes in histological condition, short term tissues proved to be more sensitive to starvation than long term tissues.

Diversos índices han sido empleados para caracterizar la condición nutricional en larvas de peces. Los criterios histológicos han demostrado ser confiables para diagnosticar la condición ya que involucran el estudio del aspecto de las células y la estructura e integridad de diferentes tejidos de las larvas. Sin embargo, debido a que el aspecto microscópico de los tejidos varía tanto como consecuencia de la condición nutricional como del estadio de desarrollo de las larvas, se hace necesario caracterizar las estructuras empleadas para diagnosticar su condición nutricional y tener en cuenta el estadio de desarrollo de los ejemplares. El objetivo principal de este trabajo fue una descripción micro-anatómica de los tejidos utilizados para determinar la condición nutricional de larvas de peces con larvas de Engraulis anchoita recolectadas en el mar Argentino. Se determinó un índice de condición histológica (ICH) para diferentes estadios de desarrollo de larvas de anchoíta, discriminándose entre los tejidos que muestran inanición sufrida a largo plazo y los que muestran inanición a corto plazo. Se observó una reducción en el ICH luego de la reabsorción del vitelo y hacia el final de la etapa larval. Los tejidos de corto plazo mostraron mayor sensibilidad a pequeños cambios en la condición nutricional.

Displacements of Argentine hake Merluccius hubbsi shoals in the spawning area of Patagonia before and during a reproductive season were analyzed. In particular, monthly changes in fish density, sex composition, size structure and spawning location were described for this stock. During October-November, hake shoals moved from deeper waters to the coast at about 44°S, where spawning took place in December. During January the main reproductive aggregations stayed near the coast (50 m depth) but displaced to the southern area (45°S); in February spawning activity diminished and spent females began to return to deeper waters. In general, this process was first completed by young spawners (35-45 cm TL), which have a breeding season shorter than the old females. We observed that males arrived at the spawning area first and remained there for a longer period than females. During the reproductive period skewed sex ratios in different sampling sites were observed. These differences in sex composition were attributable to: 1) local segregation produced by the reproductive behavior of hake, in which males form groups with a single female, and 2) migration of spent females to deeper waters, which causes male-biased samplings in coastal areas

Se analizaron los desplazamientos de los cardúmenes de merluza común Merluccius hubbsi en el área de desove de Patagonia antes del comienzo de la puesta y durante una temporada reproductiva. Se describieron los cambios de abundancia, composición de sexos, estructura de tallas y localización de los desoves. Durante octubre y noviembre, los cardúmenes de merluza migraron desde aguas más profundas hacia la costa, aproximadamente a los 44°S, donde tiene lugar la puesta en diciembre. Durante enero las principales agregaciones reproductivas permanecieron cerca de la costa (50 m de profundidad) pero desplazadas hacia el sur (45°S); en febrero la intensidad del desove disminuyó y las hembras en post-puesta comenzaron a retornar a aguas más profundas. En general, este proceso fue completado primeramente por los desovantes más jóvenes (35-45 cm LT), los cuales tienen una temporada reproductiva más corta que las hembras de mayor edad. Los machos arribaron más temprano al área de puesta y permanecieron durante más tiempo que las hembras. Durante el período reproductivo se observaron variaciones espaciales en la proporción de sexos, que fueron atribuidas a: 1) segregación local producida por el comportamiento reproductivo de la merluza, donde varios machos se agrupan con una hembra al momento de la puesta, y 2) migración de hembras en post-puesta hacia aguas más profundas, lo cual origina mayor proporción de machos en las áreas costeras