Data/hora: 04/06/2024 00:47:43

Provedor de dados: | 76
País: | Brazil
Título: | Dinâmica reprodutiva de Oligosarcus jenynsii e O. robustus (Characiformes, Characidae) na lagoa Fortaleza, Rio Grande do Sul, Brasil
Autores: | Nunes,Daniela M.; Pellanda,Mateus; Hartz,Sandra Maria.
Data: | 2004-03-01
Ano: | 2004
Palavras-chave: | Oligosarcus; Reproduction; Characidae; Southern Brazil.
Resumo: | Oligosarcus jenynsii (Günther, 1864) and O. robustus Menezes, 1969 are fish species distributed in Rio Grande do Sul, Brazil, Uruguay, and northern Argentina. The reproductive period and recruitment, sex ratio, absolute and relative fecundity, and body length at first gonadal maturation of the two carnivorous species from Fortaleza Lagoon were analized. The specimens were sampled monthly, from May 2000 to April 2001, with fishing effort of 24 hours/month, using stationary gillnets of different mesh sizes and seine net (three samples per edge). The records of each individual included total length, total weight, gonad weight, sex and gonadal maturity stage. The reproductive period of both O. jenynsii and O. robustus ranges from May/June to November/December, according to the bimonthly variation of the mean values of gonosomatic index, and the relative frequencies of the gonadal maturation stages. Recruitment of new individuals to the population occurs from November/December to March/April. The sex ratio is different from 1:1 for O. jenynsii and similar to 1:1 for O. robustus. The mean absolute fecundity, calculated by counting sub-sampled oocytes from mature females, was 14,483 oocytes for O. jenynsii, and 16,308 oocytes for O. robustus. The first maturation curve shows that O. jenynsii begins to reproduce between 84 mm and 104 mm (total length), and O. robustus between 126 mm and 146 mm, probably at similar ages.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Português
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212004000100001
Editor: | Museu de Ciências Naturais
Relação: | 10.1590/S0073-47212004000100001
Formato: | text/html
Fonte: | Iheringia. Série Zoologia  v.94 n.1 2004
Fonte: | info:eu-repo/semantics/openAccess