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I SIMPOSIO IBEROAMERICANO DE ECOLOGÍA REPRODUCTIVA, RECLUTAMIENTO Y PESQUERÍAS
Reproduction and larval ecology of the Brazilin sardine,
Sardinella brasiliensis (Steindachner, 1879): past and
present studies
June Ferraz Dias & Mario Katsuragawa
Instituto Oceanográfico (USP), São Paulo (Brasil). junedias@usp.br
Sardinella brasiliensis (Steindachner, 1879) is the commercial most important fish in
southeastern Brazilian coast. Large variations and decline in its populations and stocks size
have inspired intensive studies, both in early life history and in the adult phase of this species.
Causes of these variations have been related to the impact of fishery pressure on the adult and
oceanographic conditions during the spawning season. This study describes investigations of
the larval ecology and condition, and female reproductive biology of S. brasiliensis from the
area of its distribution. Ichthyoplankton was sampled with bongo nets in six survey cruises
during austral summer (1987-1988, 1990-1991, 1991-1992, 1992-1993, 2007-2008 and 2008-
2009). The estimated abundance of Brazilian sardine larvae varied from 8.31 to 13.82
larvae.m -2 . Larval nutritional condition was evaluated by protein content and/or RNA/DNA,
and the results showed that better condition larvae were related to the more pronounced
summer intrusions of the nutrient enriched South Atlantic Central Water (SACW) over the
continental medium and inner shelf. The SACW also acts as retention mechanism. Adult
females sardine were collected in survey cruises during 1983 and 2007-2008 for estimating
batch fecundity and spawning frequency. As an indeterminate multiple spawner species, the
batch fecundity varied from 4,500 to 35,000 hydrated oocytes per batch. The presence of
atresia and melanomacrophage centers were considered low. Time of spawning evaluated by
post-ovulatory follicles (POF) is the same estimated previously by ichthyoplankton analysis
(around midnight) and despite the difficulties associated in ageing POF, estimation of
spawning frequency varied from 6 to 11 days.
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