New record and new species of Laubierpholoe Pettibone, 1992 (Annelida, Sigalionidae) from the soft bottom of submarine caves near Marseille (Mediterranean Sea) with discussion on phylogeny and ecology of the genus

A new species of Laubierpholoe Pettibone, 1992 (Annelida, Sigalionidae), Laubierpholoe massiliana Zhadan sp. nov., was found in two submarine caves near Marseille (France). This is the first record of the genus in the Mediterranean Sea. The new species differs from congeners by inhabiting soft sediments instead of having an interstitial lifestyle and by several morphological characters: the ventral tentacular cirri slightly shorter or of similar length to the dorsal tentacular cirri, the presence of bidentate neurochaetae, the body length, and the number of segments. Molecular phylogenetic analysis using 18S rRNA and 28S rRNA sequences confirmed that the new species belongs to the genus Laubierpholoe, as well as the monophyly of the genus. The ecology of the new species and its adaptation to the cave-dwelling lifestyle are discussed. An identification key for all known species of Laubierpholoe is provided.