Estudo preliminar da dieta natural de Scylla serrata (Forsskal, 1775), durante a época seca na floresta de mangal da Península de Machangulo, na Baía de Maputo

Abstract

The species Scylla serrata is a resource of high commercial value for Mozambique, being a source of foreign exchange for the country due to its large size, but it is also highly appreciated in the tourism industry as a delicacy. The present study aims to evaluate the natural diet of S. serrata during the dry season in the mangrove forest of the Machangulo Peninsula in Maputo Bay, by identifying its food composition, determining the importance of items and trophic position. The study of the natural diet of S. serrata had as a sampling period the middle of the rainy season between the months of June and August 2021, with 70 adult individuals with CW> 80 mm being acquired and subsequently separated into males and females. The individuals were dissected in order to remove their stomachs. After their removal, the stomachs were opened and their contents observed with the aid of an inverted optical microscope and binocular magnifying glass. The stomach contents were analyzed using the frequency of occurrence and numerical frequency method, where 7 categories were observed, of which the most important items were MOOA-MM (56%), MOO (50%), debris (47%) in males and MOÑI (44%), MOOV (58%), debris (47%) and Crustaceans (42%) in females of S. serrata, occurring in more than 60% of the stomachs. The subgroups of this in terms of numerical frequency that constituted the highest frequency were mostly debris in both samples, followed by the remains of carapaces and other parts of unidentified crustaceans, MOOA-MM and shells. The study demonstrated that S. serrata crabs have a mixed diet showing an apparent preference for crustaceans, shells, unidentified organic matter, muscle mass and detritus, thus showing that they have an opportunistic omnivorous diet where at a given period they become predators preying on other crustaceans(TRADUÇÃO NOSSA)