Halichondrids or axinellids? Some problematic genera of sponges with descriptions of new species from the Strait of Gibraltar (southern Iberian Peninsula)



The axinellids and the halichondrids are two of the most conflictive sponge groups from a taxonomic point of view, owing to the simplicity of the morphological characters that would allow discrimination between taxa at a supraspecific level. In this sense, some of the species dealt with in this study provide an example of the controversy that exists when a species must be assigned to one of these groups. The species Axinyssa digitata is redescribed. We also propose to move the species Dictyonella madeirensis to the genus Scopalina, and the validity of the recent family Dictyonellidae Soest, Diaz & Pomponi (1990) is supported. Moreover, two new species are described: Dictyonella alonsoi, characterized by thick monactine megascleres which undergo different tip modifications, and Ciocalapata almae, characterized by the presence of anisostrongyloxeas in two size categories together with oxeas.