Cardumes da sardinha-verdadeira, Sardinella brasiliensis (Steindachner), em águas costeiras do estado do Rio de Janeiro, Brasil Scliools of Brazilian-sardine, Sardinella brasiliensis (Steindachner), in coastal waters of Rio de Janeiro State (Brazil)

<abstract language="eng">This paper deals with the occurrence and schol sizes of the Brazilian-sardine, Sardinella brasiliensis (Steindachner, 1879), in coastal waters of" Rio de Janeiro State (Brazil), during the years 1993-1997. The schools are more frequent and heavier in bay and surroundings of Grande Island; another area, with lesser importance, remains between the Cape of São Tome and surroundings of Cabo Frio, under influence of coastal upwelling. The heavier schools are found in April-June (autumn), soon after lhe reproduction period. The schools swim in surface waters with until 80 meters in depth. but more than 98% of them are restricted to waters until 50 meters; about 41% of schools are found in places of 10 - 20 meters, with clear reduction of their frequencies in higher depths; schools with more than 10 tons tend to swim in surface waters with 31-60 meters in depth. The schools reach the maximum size of 95 tons, but around 88% of them do not exceed the 15 tons; the smaller ones, with until 5 tons, correspond to almost 42% of those caught, with frequency reductions as increase their sizes

Population structure and somatic indexes of Hypostomus cf. ancistroides (Siluriformes, Loricariidae) collected from the Bonito river, Ivaí river basin, Turvo, Paraná

This study aimed to provide information about the population structure and somatic index of Hypostomus cf. ancistroides collected from the Bonito river, located in the Ivaí river basin. The length-weight relationship was isometric for both the sexes. The length structure analysis showed that the larger individuals (from 18.1cm to 27.0cm in length) predominated, and the lowest abundances occurred at the size extremes (9.1-12cm and 27.1-30.0cm). The reproduction period occured between October and January for the females and between November and January for the males. The liver somatic index cannot be used as an indicator of the reproduction period in either of the sexes, due to no correlation between the liver somatic index and the gonad somatic index. The gonad weight exerted no influence on the monthly mean condition factor and the correlation between the condition factor and gonad somatic index was high. The condition factor could be an indicator of the reproduction period of this species.<br>Este estudo teve o objetivo de fornecer informações sobre a estrutura populacional e os índices somáticos de Hipostomus cf. ancistroides coletados no rio Bonito localizado na bacia do rio Ivaí. A relação comprimento-peso, para machos e para fêmeas, foi isométrica. A análise da estrutura em comprimento mostrou que há um predomínio de indivíduos maiores (entre 18.1 a 27.0 cm) sendo que as menores abundâncias ocorreram nas classes de comprimentos extremas (9.1 a 12.0 cm e 27.1 a 30.0 cm). O período reprodutivo em fêmeas ocorreu entre os meses de outubro a janeiro. Os machos possuem um período reprodutivo entre novembro e janeiro. O índice hepatossomático, para ambos os sexos, não pode ser utilizado como indicador do período reprodutivo, devido à não correlação entre o índice hepatossomático e o índice gonadossomático. O peso das gônadas não influenciou o valor médio do fator de condição e foi observada uma alta correlação entre o fator de condição e o índice gonadossomático. O fator de condição pode ser um indicador do período de reprodução desta espécie