[POLLICIPES POLLICIPES (GMELIN, 1789) (CIRRIPEDIA, LEPADOMORPHA): ITS GROWTH AND POPULATION DYNAMICS IN THE REGION OF MIRLEFT (SOUTHWEST MOROCCO)

摘要

Pollicipes pollicipes (Gmelin, 1789) (a stalked barnacle) is illegally exploited by the human population of Mirleft, because of its commercial value. Accordingly, considering the current concern for the conservation of the species, we carried out a monthly monitoring programme, within our larger scale study on the population dynamics of P pollicipes, during the period April 2009-April 2010 at three sites in the region of Mirleft (Morocco): Grizim, Imin Tourgua and Sidi Mohamed Ben Abdellah. The results suggests that (1) recruitment occurs throughout the year at the three sites studied, and the intensity of this process shows temporal and spatial fluctuations; (2) the populations are very heterogeneous and contain various age classes; (3) the population density and biomass are low in relation to protected habitats; (4) pairwise comparison of parameters (wet weight/total length; dry weight/rostral-carinal length; rostral-carinal length/total length) shows a significant correlation; suggesting that these parameters vary in concert; (5) the growth rate of this species shows some variation among the site (K = 0.450 at Grizim, K = 0.460 at Imin Tourgua, and K = 0.410 at Sidi Mohamed Ben Abdellah).