Reproductive biology of the red starfish Echinaster sepositus (Echinodermata, Asteroidea) from the Algerian west coast

ABSTRACT This work aims to describe for the first time the reproductive biology of the red starfish Echinaster sepositus at the western region of Algeria (Mostaganem). The population of E. sepositus is characterized by a sex ratio of 1:2 (female: male). The relation between arm length and wet body weight indicate a negative allometric growth. Histological study reveals six stages of sexual maturity in females (I: development; II: pre-mature; III: mature; IV: partly spawned; V: post – spawning; VI: recovery) and five stages in males (I: development; II: pre-mature; III: mature; V: post-spawning; VI: recovery). The gonadosomatic index shows that there is only one spawning period per year, which happens from July to November. The gonadal maturity and gametogenesis of E. sepositus are correlated with the environmental factors namely temperature and photoperiod.