Preliminary estimate of spawning frequency and batch fecundity of Brazilian flathead, &lt;i&gt;Percophis brasiliensis&lt;/i&gt;, in coastal waters off Buenos Aires Province

M I Militelli,G J Macchi

doi:10.3989/scimar.2001.65n2169

Abstract

Spawning frequency and batch fecundity were estimated for Brazilian flathead, Percophis brasiliensis, in Argentine coastal waters. Samples of this species were collected during the spawning period in November 1998 and 1999. Spawning frequency, determined using the percentage of females with postovulatory follicles, was about 17% during November 1998. This percentage indicates that P. brasiliensis spawned, on average, once every 6 days during this month. Batch fecundity, estimated from counts of hydrated oocytes, was fitted to a power function of length and a linear function of ovary-free female weight. Batch fecundity ranged from 37,500 (47 cm total length) to 614,300 (68 cm total length) hydrated oocytes. Relative fecundity estimated for the two years sampled ranged from 95 to 672 hydrated oocytes/g of female weight (ovary-free). Annual differences in the size-batch fecundity relationship and in the relative fecundity were observed.

Highlights

This percentage indicates that P. brasiliensis spawned, on average, once every 6 days during this month
Relative fecundity estimated for the two years sampled ranged from 95 to 672 hydrated oocytes/g of female weight
The objective of the current study is to get a preliminary estimate of spawning frequency and batch fecundity of P. brasiliensis in the coastal area of the Buenos Aires Province

Summary

Introduction

The Brazilian flathead, Percophis brasiliensis (Fam. Percophididae) is a demersal coastal species of the Southwest Atlantic which is distributed from. Rio de Janeiro (Brazil) (23°S) to the north of the Chubut Province (Argentina) (44oS) (Tomo, 1969; Verazay, 1976; Gosztonyi, 1981; Cousseau and Perrotta, 1998). The Brazilian flathead constitutes an important resource for the coastal fisheries of Argentina (Fernández Giménez, 1995). The most abundant catch occurs in summer, between 40o and 43o S, at depths between 40 and 75 m. In the last three years fishing activity on this species has increased because the traditional Argentine resource, hake Merluccius hubbsi, has decreased drastically (Aubone et al, in press).

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