Comportement alimentaire de quelques espèces d'holothuries aspidochirotes inféodées aux herbiers de posidonie de la côte de Mostaganem (SALAMANDRE)

Abstract

The aspidochirote Holothurians commonly called "sea cucumber" are very characteristic echinoderms their dietary behavior "deposit feeders". This are the major representatives of the benthic compartment of the ecosystem Posidonia Oceanica. A study of feeding behavior of aspidochirotide [Holothuria (H.) tubulosa Holothuria (L.) polite, Holothuria (P.) forskali Holothuria (P.) sanctori] subservient to the Posidonia seagrass was carried out in localities Salamander (Mostaganem) at an average depth of -3m. Our study focuses on the analysis of the organic matter of the sediment of the three sections of the digestive tract of these species, the substrate of their habitat, and their feces, to get an idea about their ability for selective organic matter. The assimilation efficiency was also discussed in this work. Sea cucumbers aspidochirote studied show a selective behavior for organic matter. This selectivity differs from one species to another, and shows high values in March, April and May (spring period), which coincides with the period of their reproductions. The values obtained for assimilation efficiency show that Holothuria tubulosa and Holothuria forskali assimilates best organic matter. Overall the strong values of assimilation efficiency coincide with the breeding season of the species studied.