Estudo da densidade, biomassa, etologia e aspectos reprodutivos de populações do caranguejo uca annulipes, no mangai do Saco da Inhaca

Abstract

In the Saco da Inhaca mangrove, the Uca annlipes species was studied, in three sub-areas with different degrees (External area; with a mixture of Avicennia marina and Ceriops tagal vegetation, Intermediate area, with Avicennia marina vegetation with many pneumatophores and Inner area, with absence of vegetation and on a sandbank) in January, February and March 1999. For each of the sub-areas, density was studied through two counting methods (Harvest and Binoculars), Individual biomass in relation to moon phases and population size structure and some reproductive and behavioral aspects of the species. It was found for both sub-areas that: This species had variations in density, between counting per harvest and binoculars, and the average density of counting per harvest was 9.7/0.25 m2, 11.9/0.25 m2 and 8.9/0.25 m2 respectively for the external, intermediate and internal sub-areas. While for the Binoculars count it was 5.6/0.25 m2, 7.1/0.25m2 and 5.2/m2 respectively for the external, intermediate and internal sub-areas. Counting by Harvest presents higher density values ​​compared to counting by Binoculars. There is almost always a greater number of holes when compared to the density of the two counts. Greater biomass is registered in the intermediate sub-area (Avicennia marina and pneumatophoros). Greater number of males with a combination of Left/Original (E/O) and Right/Original (D/O) chela, similarity regarding the position of the chelas (49.1% and 50.95% respectively Right (R) and Left (L) ), a strong state dominance of that Original (82.1 5%) in relation to Regenerated (17.9%). There is a strong correlation between the size (width of the carapace) of individuals and their weight (g). There is occurrence of ovated females throughout all sampling days and a higher number of ovated females with size (>10<=11 mm). Predominating more in the waning quarter and full moon. Movements from places with holes to places without holes and which are not linked with the search for organic matter in the sediment.