Aspects of the reproductive biology of the toadfish, <i>Halobatrachus didactylus</i> (Schneider, 1801) (Pisces: Batrachoididae)

Abstract

SUMMARY: 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 Cádiz 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.

Patterns of shelter usage and social aggregation by the vocal Lusitanian toadfish

“…Class B and C were only represented by type I males, with B-sized animals ranging in MW from 100 to 148 mm (mean = 120.4 mm) and TL from 326 to 452 mm (mean = 387 mm) and C males ranging in MW from 150 to 195 mm (mean = 164.1 mm) and TL from 410 to 495 mm (mean = 452 mm). The fact that larger Wsh (B and C) were only represented by parental males (type I) is consistent with previous studies carried out with Iberian Lusitanian toadWsh populations (Palazón-Fernández et al 2001;Modesto and Canário 2003).…”

“…Marine teleosts of the family Batrachoididae include toadWshes and midshipmen and are established vertebrate models for the study of acoustic communication and audition (Bass and McKibben 2003) as well as in other areas such as ethology and endocrinology (Palazón-Fernández et al 2001). Batrachoidids seasonally migrate from deeper coastal and estuarine waters to intertidal and subtidal zones where males dig burrows under rocks to prepare a nest for spawning (Gray and Winn 1961;Brantley and Bass 1994;Costa 2004;Cotter 2008).…”

“…Females release a low number (hundreds) of large eggs (5-8 mm diameter) (Palazón-Fernández et al 2001;Costa 2004) in a single batch (Modesto and Canário 2003) whose high survival is assured through male parental care. The spawning season extends from March to August with a peak in May-June in the Bay of Cádiz, Southern Spain (Palazón-Fernández et al 2001), but in Portugal it extends from May to July (Modesto and Canário 2003;Costa 2004). The main constraint for reproduction in H. didactylus, as in other batrachoidids, is water temperature, and breeding activity is only observed with temperatures higher than 18/19°C (Costa 2004).…”

Cloning and characterization of Vasa gene expression pattern in adults of the Lusitanian toadfish Halobatrachus didactylus

“…H. didactylus does not have a high commercial value in southwestern European countries, but it has been employed in many multidisciplinary studies, such as biology, haematology, toxicology and ecology as well as for experimental cardiological purposes (Borges et al 2003, Campana et al 2003, Desantis et al 2007, Soares et al 2008, Palazón-Fernández et al 2011, Vasconcelos et al 2011. In addition, different aspects of reproduction have been studied in H. didactylus (Palazón-Fernández et al 2001, Modesto & Canário 2003. Recently, cytogenetic and molecular studies have been carried out (Merlo et al 2007, Úbeda-Manzanaro et al 2014 in Batrachoididae fish species, which are considered one of the most highly evolved groups of marine teleosts (Modesto & Canário 2003).…”

“…This species is distributed on the eastern coast of the Atlantic Ocean, from the Bay of Biscay (Spain) to Ghana, and on the western Mediterranean coast, and it is the only species of this family found in European waters. The spawning season of H. didactylus extends from March to August, with a peak in May−June (Palazón-Fernández et al 2001). H. didactylus does not have a high commercial value in southwestern European countries, but it has been employed in many multidisciplinary studies, such as biology, haematology, toxicology and ecology as well as for experimental cardiological purposes (Borges et al 2003, Campana et al 2003, Desantis et al 2007, Soares et al 2008, Palazón-Fernández et al 2011, Vasconcelos et al 2011.…”