Aspects of the reproductive biology of the toadfish, &lt;i&gt;Halobatrachus didactylus&lt;/i&gt; (Schneider, 1801) (Pisces: Batrachoididae)

José L Palazón-Fernández,Carmen Sarasquete,Alberto M Arias

doi:10.3989/scimar.2001.65n2131

Abstract

The biology of Halobatrachus didactylus has received special attention during recent years because of its use as an experimental species in toxicology and cardiology experiments. The object of the present work is to supply basic information about the reproductive biology of this species. Samples were collected in Cadiz Bay between February 1999 and March 2000. A total of 901 specimens (440 females and 461 males) were examined. Sex ratio did not differ from the theoretical 1:1, except in May 1999, and February 2000. Minimum size at maturity was 191 mm total length for females and 160 mm total length for males. Approximately 50 % of the population matured at 262 mm for females and 302 mm for males. The spawning season extends from March to August, with a peak in May-June. Fecundity ranged from 227 to 1233 eggs/female, and was related to body length and weight. Length-weight relationship for the sexes differed, and showed positive allometry. The condition factor showed a minimum in the spawning season, which is interpreted as the result of mobilization of somatic energy reserves needed for reproductive development, and/or the use of reserves stored in the body as a source of energy in spawned fish, influenced by reduced feeding during this period.

Highlights

The toadfishes (Family Batrachoididae) include genera and 40 species of shallow water bottomdwelling fishes that live in soft sand, rocky bottoms and reefs (Cervigón, 1980)
Some batrachoid species have traditionally been used as laboratory animals in the field of physiology (Hopkins et al, 1997; Gilmour et al, 1998; Perry et al, 1998; Paert et al, 1999), toxicology (Gutiérrez et al, 1978; Sinovcic et al, 1980; Sarasquete et al, 1982), ethol*Received September 20, 2000
Along the Iberian Peninsula, the Batrachoidids are represented by only one species, Halobatrachus didactylus

Summary

Introduction

The toadfishes (Family Batrachoididae) include genera and 40 species of shallow water bottomdwelling fishes that live in soft sand, rocky bottoms and reefs (Cervigón, 1980). Ogy (Ament et al, 1997; Bass, 1998), neurobiology (Rabbitt et al, 1995; Fine et al, 1996; Hirsch et al., 1998), cardiology (Benítez et al, 1994a,b; Coucelo et al, 1996), and endocrinology (Fine et al, 1996; Knapp et al, 1999). Owing to this, their biology has been extensively studied in most of species. Its distribution extends from the Bay of Biscay to Ghana and the west Mediterranean (Roux, 1986)

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