Contribution à l'étude du régime alimentaire chez quelques espèces d'holothuries de la côte de Mostaganem

Abstract

This study aimed to investigate the diet of five sea cucumbers species (Holothuria poli, Holothuria tubulosa, Holothuria forskali, Holothuria sanctori and Holothuria arguinensis) from the locality of Salamander (Mostaganem). The trophic sources used by the studied holothurians consist of plant component (Diatoms, Algae, Cyanophyceae, Posidonia leaves) and animal component (Sponge’s ossicles, Holothurian’s ossicles, Crustacea, Mollusc shells, Foraminifera, sea urchin spines and Nematodes). Foraminifera is the main food consumed by all Holothurians (44.03%, 42.41%, 33.11%, 32.67% and 22.38% respectively in Holothuria tubulosa, Holothuria forskali, Holothuria poli, Holothuria sanctori and Holothuria arguinensis). Holothurians digestive contents shows two groups of species: a group composed of Holothuria poli and Holothuria tubulosa showing a preference for mollusk shells and a second grouping together Holothuria forskali and Holothuria sanctori with a preference for Algae and Spicules of Sponge. Holothuria arguinensis stands out from the two groups and exhibits a preference for algae, sea urchin spines and sea cucumber ossicles. Non-metric multidimensional scaling (NMDS) confirm our results and shows that Holothuria arguinensis can be qualified as a generalist species with trophic plasticity.