The feeding behaviour of the red mangrove crab Sesarma meinerti De Man, 1887 (Crustacea: Decapoda: Grapsidae) and its effect on the degradation of mangrove leaf litter

Abstract

Feeding of Sesarma meinerti de Man was studied in the laboratory and at the Beachwood Mangrove Reserve. In the field, mangrove leaf litter formed 74,6% of the diet. Crabs showed a preference for leaves in the order: yellow Bruguiera gymnorrhiza (L.) Lam. > yellow Avicennia marina (Forssk.) Vierh. > green B. gymnorrhiza > green A. marina. In the laboratory, a positive correlation was observed between relative consumption and degree of decomposition. Crabs fed with both tannin and tannin-free leaves showed a preference for the latter. Removal of B. gymnorrhiza leaves by S. meinerti was high throughout the year, whereas dry mass loss attributable to consumption varied according to season. It is suggested that S. meinerti plays an important role in the degradation of mangrove leaf litter.