Dinâmica populacional e distribuição espaço- temporal de Tivela mactroides no Litoral Sul de Alagoas.

Abstract

The bivalve Tivela mactroides, popularly known as maçunim, has been collected in a disorderly manner, without any control or supervision of the competent environmental bodies on the beach of Pontal do Peba, AL. The present work aims to clarify aspects of the population structure of the bivalve T. mactroides and its spatio-temporal distribution in a region subject to extraction. Samplings were carried out between October 2009 to September 2011, on the beach of the village of Pontal Peba, Piaçabuçú, Alagoas. Samples were collected in three transects perpendicular to the beach, 250m far from each other. In each transect samples were collected in triplicate on three points with the aid of a quadrat.The material was sieved ain 0.5 mm and preserved in alcohol 70%. In the laboratory, the individuals were quantified and measurements of length, height and width were done with the aid of a caliper. The wet weight of each individual was measured using a digital scale (0.01g). The density value of the individuals ranged from 1.85 to 123.15 ind /m 2 Spatial significant differences among transects or regions of meidolitoral were not found. Temporal differences among periods of sampling were significant. The best correlation among measures was found for height (mm) and weight (g) (R ² = 0.874), suggesting that the minimum size of capture should bebased on the height of the individual. More Specific studies are necessary to provide information about the biological and ecological characteristics of the species.