Abondance des larves d'étrille (Macropipus puber, L.), d'araignée (Maia squinado, Herbst) et de tourteau (Cancer pagurus, L.) sur la côte ouest du Cotentin (Manche) de 1977 à 1979

Within the framework of the ecological study related to the construction of a coastal nuclear power plant in Flamanville (westcoast of Cotentin, English Channel), zooplancton was sampled in the vicinity from april 1977 to september 1979 according to a monthly and even fortinghtly frequency. This paper presents the results obtained about the larvae of three commercial brachyuran decapoda species : the Velvet Swiming crab (Macropipus puber, L.), the Spinous Spider Crab (Maia squinado Herbst) and the Edible Crab (Cancer pagurus, L.). For the three annual cycles considered saisonal variations in abundance of zoeal and megalopa stages were represented. For the 1978 and 1979 samples we made, in addition, the distinction between the successive zoeal stages. Variations in abundance of the first zoeal stage contribute to specify, for each species, the extend of hatching period and to suggest for one of them (Maia squinado) the existence of a single annuel spawning. Comparaison with some data obtained in other regions (north of the Bay of Biscay and Southern Bight of the North sea), where similar studies are at present in progress, permits us to have a better understanding of the results concerning the Flamanville area. NOT CONTROLLED OCR