Size at hatching and incubation period of Sympterygia bonapartii (Müller & Henle, 1841) (Chondrichthyes, Rajidae) bred in captivity at the Temaiken Aquarium

Abstract

Numerous studies have examined the reproductive biology in several species of the family Rajidae (Holden et al., 1971; Luer & Gilbert, 1985; Ellis & Shackley, 1995; Koop, 2005). Previous studies, however, on the smallnose fanskate Sympterygia bonapartii (Mu¨ller & Henle, 1841) an endemic species in South American temperate waters, distributed from Rio Grande do Sul, Brazil (32° S) to Rawson, Argentina (44° S) (McEachran, 1982) have focused on taxonomy (McEachran, 1982), distribution (Menni & Stehmann, 2000) and trophic ecology (Barrera Oro & Maranta, 1996). Though recent studies have further examined its abundance and reproductive biology (Mabragan˜a et al., 2002; Oddone & Velasco, 2004), the incubation period and size at hatching are poorly known.