Some insights on the phylogeny of Algerian shallow-water sea cucumber species (Holothuroidea: Aspidochirotida)

Abstract

Phylogenetic analyses from the fraction of mitochondrial gene (16S mDNA) sequenced for 26 individu-als (in general, five species sampled in various shallow-water locations along the Algerian coast) clarified taxonomic uncertainties. This study shows that: 1) the two color morphs of Holothuria (P.)sanctorithat have been debated in some of the literature form a well defined clade; 2) Holothuria (H.)stellatiwhose confusion has always acknowledged, is genetically distinct from the other species; 3) Holothuria (H.)tubulosa,the most common species, and the “best known” species in the Mediterranean Sea, forms a clade with two well separated populations. Few specimens of holothurians analyzed in our collection have given unusual DNA sequences. However, it is clear that one specimen will probably represent either another species previously unknown, or a hybrid between two known species — H. (R.)poliiand H. (H.)stellati.