Abstract
The gastropod Neritina virginea (Linnaeus, 1758) wich has wide distribution, is used as a bioindicator, as an economic resource for the handicraft, and has ecological importance, has been little studied . This project proposes to study the population dynamics of N. virginea in the intertidal zone of the Araçá Bay, São Sebastião, SP. The samplings will last 12 months and the objectives are: to determine the spatial and temporal distribution, in relation to density, the migratory behavior, the secondary production and biomass, the growth, mortality and longevity rates, and the characterization of the diet of the species. The samplings will be made monthly, in two ways: 1) Nested ANOVA design, in different environments, aimed at determining the spatial distribution and the contribution of three scales in the variation of this distribution; 2) Active search, is intended to increase the number of individuals collected, marked and recaptured, for the study of migratory behavior to be possible. Individuals collected will be marked and from each individual will be taken five measures: height, length and width of the shell, and length and width of the opening of the operculum. To estimate growth, mortality and longevity rates, we will use the generalized model of von Bertalanffy. Secondary production of wet and dry seasons and annual biomass will be evaluated by calculating the ash-free dry weight. To characterize the diet, the contents of the digestive tract will be identified in order to asses the strategy trophic and diet specialization, as well as the importance of some food items.
|