etude biologique de scylla serrata en vue de la gestion de ressource dans la région du menabe : identification de la taille à la première maturité sexuelle et la période de la reproduction

Abstract

To assess the biological size of crabs at sexual maturity and the season of reproduction of
Scylla serrata, a study was conducted in Belo-sur-Mer, southwest Madagascar from October
2013 to February 2015. The variation of size at maturity and somatic gonad report variation were
estimated for crabs collected from 4 different villages by dissection and measurement of sample.
Ovaries showed a macroscopic differentiation in size and coloration with maturation and were
classified according to 4 ovarian developmental stages. Male gonad maturity was distinguishable
into immature classes with vas deferens appraisal and testis. Analysis showed that carapace
length was significantly related to maturity and size at sexual maturity was different between
sexes. Results of analysis showed that estimated size at 50% maturity is 12.03 cm for female and
11.01 cm for male crabs. The season of reproduction of mud crab was estimated in April, June
and October-December. Regional-level management should focus on the protection of resource
and further investigations should determine if regional differences exist for S serrata size at
maturity within Madagascar.
Key words: reproduction, crab, gonad, Scylla serrata, maturit