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

Abstract

Two mature Sympterygia bonapartii held in captivity laid a total of 136 egg cases, 33 of them were incubated at constant temperature (16·5° C), salinity (36) and photoperiod (12L:12D). The hatching rate was 100%. Juvenile fish hatched after 135 ± 10 days (mean ± s . d .) and the mean total length, disc width and mass at hatching were 140 mm, 86 mm and 15·1 g respectively.