A new diagnosis of the genus Delectona (Porifera, Demospongiae), with a description of a new species from the Alboran Sea (western Mediterranean)

Abstract

A redescription of the genus Delectona is provided, based on information gained by the finding of a new species, D. alboransis, from the Alboran Sea (southwestern Mediterranean Sea), Up to now, this genus contained only one species: Delectona higgini, from the Indian Ocean, which has not been recorded since 1880. The presence of megascleres in the new species and the different ranges of amphiaster lengths of the two species are the main features allowing a differentiation. In addition, the excavating capability of sponges of this genus is questioned, following the observations on the external morphology of D. alboransis. Our results support the hypothesis of other authors that some areas of the circalittoral level of the Alboran Sea may represent a redoubt of relict species with Indo-Pacific affinities.