Fecundity and sexual maturity of the crab Macrophthalmus depressus (Brachyura: Ocypodidae) from Inhaca Island, Mozambique

Abstract

Some reproductive aspects of the ocypodid crab Macrophthalmus depressus, were investigated, with emphasis on fecundity and sexual maturity. Random intertidal crab samples taken in October 2002 were identified, sexed, measured, checked for the presence of eggs on female pleopods, dissected for gonad analysis and their egg numbers were determined. Fecundity averaged 1249.86 ± 991.96 eggs, ranging from 100 to 5000 eggs, increasing in accordance with female size. A very low variation in number of eggs was observed within the same size class, probably indicating synchronous spawning within the same reproductive season. Gonad analysis suggested that females and males become mature at carapace widths of 13.4 and 13.6mm, respectively. The potential effects of variations in fecundity in this species, and in the Ocypodidae family, were compared and discussed.

Keywords: Macrophthalmus depressus, egg production, morphological maturity, reproduction, Africa

African Journal of Aquatic Science 2005, 30(2): 179–183