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The Argentine hake Merluccius hubbsi is a demersal-pelagic species on which few studies have been undertaken, despite its importance for the fisheries of the South-Southeastern Brazilian region, . The species is the most important commercial fishery resource in Uruguay and Argentina, where several studies have permitted the proper monitoring of the species. The ovarian maturation of the Argentine hake is analysed in this study. A scale of maturation is presented in the light of the oocyte development and the use of macro and microscopic scales of ovarian maturation are compared. It was detected that the oocyte types and derived structures present in the ovaries are similar to those already described both for the species and for teleosts in general; group synchronous development and multiple spawning are typical. The identification of ovarian maturation based only on external morphological characteristics of the gonads presents many errors, mainly in the characterization of the stages of maturation, which makes imperative the parallel analysis of the oocyte development, undertaken through histological ovarian cross-sections.A merluza Merluccius hubbsi é uma espécie demerso-pelágica sobre a qual, apesar de sua importância nas pescarias da Região Sudeste-Sul do Brasil, poucos estudos foram realizados. Neste aspecto, destacam-se o Uruguai e a Argentina, países onde ela é o principal recurso pesqueiro e onde a existência de inúmeros estudos tem permitido o monitoramento da espécie. Neste estudo a maturação ovariana da merluza é analisada. Através do desenvolvimento ovocitário, apresenta-se uma escala de maturação e compara-se o emprego de escalas macro e microscópicas de maturação dos ovários. Constatou-se que os tipos de ovócitos e estruturas derivadas presentes nos ovários são semelhantes aos já descritos para a espécie e para teleósteos; o desenvolvimento dos ovócitos é sincrônico em grupos e a desova é parcelada. A identificação da maturação ovariana com base apenas em características morfológicas externas das gônadas apresenta muitos erros, principalmente na caracterização do estádio em maturação, sendo imprescindível a análise paralela do desenvolvimento ovocitário, realizada através de cortes histológicos dos ovários.

Summary:In order to characterize the ontogeny of Anchoa tricolor, the morphology and morphometry of sagitta otoliths were described. A total of 397 pairs of sagitta otoliths of A. tricolor (20 to 85 mm) were measured and analysed by means of digital images. Morphological description was done in terms of shape and features. The Huxley model was fitted to otolith length against total length (TL) and weight (TW), and residual analyses were done in order to detect the polyphasic growth. Six shape indices were calculated (otolith height/otolith length and otolith length/total length aspect ratios, rectangularity, roundness, relative sulcus surface and rostrum index) and after size effect removal, they were analysed in terms of TL. The results of these analyses allowed three distinct growth phases to be identified: (1) up to 40 mm TL and related to low swimming ability; (2) between 41 and 60-70 mm TL, when fish displacements increase but the first maturation has not yet occurred; and (3) after 71 mm TL, when fish become adults. Landmarks and semi-landmarks were used to analyse relative warps during the otolith development. The MANOVA analysis between the centroid size and class intervals showed significant differences in the interaction of all classes except between 71-80 and 81-90 mm.Keywords: shape index; geometric; morphometry; Engraulidae; Brazil; description.Desarrollo ontogénico del otolito sagitta de la anchoa, Anchoa tricolor, en un estuario subtropical Resumen: Se describen la morfología y morfometría de los otolitos sagitta de Anchoa tricolor con el objetivo de caracterizar su ontogenia. Se midieron un total de 397 pares de otolitos sagitta de A. tricolor (20 a 85 mm) y se analizaron por medio de imágenes digitales. La descripción morfológica se hizo en términos de forma y características. Se ajustó el modelo de Huxley a la relación longitud del otolito, longitud total (TL) y peso (TW), respectivamente, y se realizaron análisis de residuos para detectar el crecimiento polifásico. Se calcularon seis índices de forma (OH/OL y OL/LT radios de aspecto, rectangularidad, redondez, superficie relativa del sulcus e índice de rostrum) y, una vez eliminado el efecto de talla, se analizaron en términos de longitud total. Los resultados de estos análisis permitieron identificar tres fases distintas de crecimiento: (1) una fase inicial, hasta 40 mm TL y relacionada con una habilidad natatoria baja; (2) entre 41 y 60-70 mm TL, cuando los desplazamientos del pez aumentan, pero aún no se ha producido la primera madurez y (3) superior a 71 mm TL, cuando el pez es ya adulto. Se utilizaron puntos homólogos y puntos equidistantes para analizar deformaciones relativas durante el desarrollo del otolito. El análisis MANOVA entre el tamaño del centroide y los intervalos de clases de talla mostraron diferencias significativas en la interacción de todas las clases, excepto entre 71-80 y 81-90 mm.Palabras clave: índice de forma; geometría; morfometría; Engraulidae; Brasil; descripción.

The concern in mitigating the negative impact generated by the discharge of nutrients in the receiving water body is a challenge for the sustainable development of Brazilian fish farms. Thus, the purpose of this study was to evaluate the water quality and environmental impact caused by trout farming system effluent with focus on discharge of phosphorus. Sampling was performed on a weekly basis in triplicate from September to November 2010. Sample sites were distributed according to the water flow: upstream from trout farming system, water supply, effluent, artificial wetland, mixing zone and downstream (60 m from effluent). In the field, pH, conductivity, dissolved oxygen, water temperature and turbidity were measured. In laboratory, nitrogen and phosphorus series, chlorophyll a, total solids suspended and their organic and inorganic fractions were analyzed. For the good growth of trout in production system, the abiotic factors described in the water quality monitoring demonstrated acceptable values. Environmentally, after passing through the production system and artificial wetland, there was an increase in concentrations of total phosphorus, total nitrogen, orthophosphate, ammonium, chlorophyll a, total solids suspended and their organic and inorganic fractions (P < 0.05). These results are related with the quality of feed, feeding management and the inefficiency of the artificial wetland. Therefore, it is necessary to use best quality feed to meet the nutritional requirements of trout, maintaining an optimal feed conversion and reducing pollution generated by effluent.

A B S T R A C TThe drawings, detailed pictures, precise descriptions and measurements that characterize otoliths must be made available for studies in various areas, including taxonomy, phylogeny, ecology, fisheries, paleontology, diversity, predator-prey relationships and modeling. The Collection of Teleostei Fish Otoliths of Southeastern-Southern Brazil (COSS-Brasil) of IOUSP contains 45,000 pairs of otoliths from 210 species. This publication is the first in a series that will constitute an atlas of Teleostei otoliths for southeastern-southern Brazil and presents the results of the morphologic and morphometric analyses of 11 Gadiformes and 36 Perciformes species by means of the most commonly used features, measurements and indices. Three otoliths of each species were illustrated and photographed whenever possible. The frequency of occurrence was calculated for each characteristic by total length classes (TL), and the ontogenetic differences were analyzed (multiple χ2 test; significance 0.05). Morphometric analyses were conducted for each characteristic per total length (TL) class and for the whole sample, and the ontogenetic differences were analyzed. R E S U M OA disponibilidade de desenhos, fotos detalhadas, descrições precisas e medidas que caracterizem os otólitos são ferramentas imprescindíveis para diversas áreas: taxonomia, filogenia, ecologia, pesca, paleontologia, diversidade, relações presa/predador e modelagem. Da Coleção de Otólitos de Peixes Teleósteos da Região Sudeste-Sul do Brasil (COSS-Brasil), IOUSP, constam quarenta e cinco mil pares relativos a 210 espécies. Esta publicação é a primeira de uma série que constituirá um atlas de otólitos para Teleostei da região sudeste-sul brasileira e apresenta os resultados de análises morfológicas e morfométricas de 11 espécies de Gadiformes e 36 de Perciformes das medidas e índices usualmente realizados. Foram desenhados e fotografados três otólitos de cada espécie sempre que possível. A frequência de ocorrência foi calculada por classes de comprimento total (TL) e para toda a amostra, e diferenças ontogenéticas foram analisadas.

Ariids such as Genidens genidens are particularly susceptible to overfishing because of their complex reproductive mechanisms, which result in slow replenishment of stocks. In this study, we obtained data about the reproductive ecology of the catfish G. genidens in the Guanabara Bay estuary, Rio de Janeiro, Brazil, providing supporting information for management of its fishery. The sex ratio, mean size of each sex at first sexual maturation, and female fecundity were determined and the reproductive period was characterized. The males:females ratio was 1:2. The fecundity is low and increases proportionally to the females’ growth in total length and weight. The breeding season occurs during the warmest months of the year, with spawning extending from October through March and incubation from December through April. Sexual maturation is late, with males maturing at a larger size than females. Skipping spawning was also identified in females. Based on the reproductive biology, it is suggested that the catch be restricted to individuals larger than 20 cm, considering the L75 of the males, and that fishing be prohibited from December through March, to include the main period of spawning season by females and oropharyngeal incubation by males.