Abstracto

THE TAXONOMIC STATUS OF HOLOTHURIA (HOLOTHURIA) TUBULOSA FROM THE ALGERIAN COAST WITH THE DESCRIPTION OF A NEW SPECIES HOLOTHURIA ALGERIENSIS NOV. SP. (ECHINODERMATA: HOLOTHURIIDAE)

Farid Bensalah

In the present study we redescribe the systematics of some holothurian species collected from different localities of the Algerian coastal waters. Morphological (anatomical and endoskeletal) and previous molecular studies showed the presence of two distinct morphotypes of Holothuria (Holothuria) tubulosa (A & B). Morpho type A corresponds to the classical Holothuria (Holothuria) tubulosa (Gmelin 1791), described by Koehler (1921); while morpho type B, we believe, represents a species new to science with characteristics significantly different from those of Holothuria (Holothuria) tubulosa A. Statistical methods (hierarchical clustering) confirm significant differences between these two morpho types. To better visualize these differences, measurements made on ossicles of Holothuria (H.) tubulosa A & B (Holothuria algeriensis nov. sp.) were compared to other species that were present in our collection including the classical Holothuria (H.) tubulosa from Banyuls sur Mer (France) and the north-eastern Atlantic species, Holothuria (Roweothuria) arguinensis (Koehler & Vaney, 1906) recently recorded from Algerian waters and the Mediterranean Holothuria (Roweothuria) poli (Delle Chiaje, 1824). We conclude that the two morpho types of H. (H.) tubulosa are significantly different to warrant the recognition of a new species for the B form herein called H. (H.) algeriensis nov. sp.