| The Thoosidae (Porifera, Demospongiae, Tetractinellida) currently includes the genera Thoosa, Alectona, and Delectona. To this date, molecular data are only available for Alectona. In this study, the phylogenetic affinities of the genera Thoosa and Alectona have been investigated with the species T. mismalolli, T. calpulli, and T. purpurea from the Mexican Pacific using morphology and three molecular loci: the mitochondrial cytochrome oxidase subunit 1 (CO1 mtDNA), 28S rRNA (fragment D2), and 18S rRNA. Morphology and embryology showed that these genera are quite different from the rest of the tetractinellids because larvae of Alectona and Thoosa have unique features in sponges, such as the presence of monaxonic discs in Thoosa and tetraxonic discs in... |
