Data/hora: 06/06/2024 02:36:17

Provedor de dados: | 49
País: | Brazil
Título: | Reproduction of the silver John dory Zenopsis conchifer (Actinopterygii: Zeiformes) based on virgin stock condition
Autores: | Vaz-dos-Santos,André Martins; Rossi-Wongtschowski,Carmen Lúcia Del Bianco; Honji,Renato Massaaki; Bannwart,Denis.
Data: | 2014-01-01
Ano: | 2014
Palavras-chave: | Spawning period and area; Length at first maturation; Sex ratio; Gonadosomatic index.
Resumo: | This study describes the reproduction of the silver John dory, Zenopsis conchifer, based on data collected before its fishery exploitation in the southwestern Atlantic, Brazil, in the early 2000s. Biological material was collected through bottom-trawl surveys in 2001 and 2002 from depths of 100 to 600 m. A total of 1,056 individuals ranging from 57 to 504 mm Ls were analyzed. A sex ratio analysis showed that males were predominant among the shorter fishes (&lt; 240 mm Ls) and females among the longer ones (&gt; 320 mm Ls). Between 240 mm and 319 mm Ls sex-ratio was 1:1. The silver John dory is a multiple spawner. Spawning is protracted and more intensive during August and November, when both females and males in spawning capable actively spawning and in regression/regeneration stages were predominant. In this period average values of gonadosomatic index were also higher. For both sexes, the first maturation occurs at 220 mm Ls and at 240 mm Ls all fish can be considered adult. The recruitment apparently takes place from February to May. The length-weight relationships fitted to all specimens and for both sexes yieldedb coefficients of ∼2.7. The virgin stock ofZ. conchifer here characterized, may serve a basis for future studies on the effects of fisheries on the reproduction of the species.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032014000300120
Editor: | Instituto Virtual da Biodiversidade | BIOTA - FAPESP
Relação: | 10.1590/1676-06032014006913
Formato: | text/html
Fonte: | Biota Neotropica  v.14 n.3 2014
Fonte: | info:eu-repo/semantics/openAccess