New and Little-Known Poecilosclerid Sponges from the Mexican Pacific Ocean

Five species belonging to the order Poecilosclerida are described based on material from the Mexican Pacific Ocean. Two of them are little known from this region: Biemna rhadia de Laubenfels 1930 and Discorhabdella urizae Maldonado, Carmona, van Soest and Pomponi 2001. Three species are new to science: Phorbas reginae sp. nov., a black massive sponge with 2 categories of acanthostyles, tornotes, and arcuate isochelae; Ectyonopsis sigmata sp. nov., a red encrusting sponge with acanthostyles, acanthostrongyles, ectosomal tornotes, anchorate isochelae, and sigmas; and Myxillodoryx nicolae gen. nov., sp. nov., a pinkish-red, cushion-shaped sponge with ectosomal tylotes, choano-somal acanthostyles, arcuate tridentate isochelae, unguiferate multidentate isochelae, and sigmas. The new genus Myxillodoryx gen. nov. is characterized by having 2 types of isochelae: arcuate and unguiferate multidentate. Based on the former classification of the order Poecilosclerida, we allocated this genus to the family Coelosphaeridae even if this species has 1 diagnostic feature of the family Myxillidae (unguiferate multidentate chelae). We emended the genus Ectyonopsis Carter 1883a to include species bearing anchorate or unguiferate isochelae and sigmas as microscleres. We propose to transfer 2 species described in the genus Stelodoryx (S. phyllomorpha Levi 1993 and S. chlorophylla Levi 1993) to the genus Monanchora, because they have ectosomal monactinal spicules instead of the typical ectosomal diactinal spicules of the genus Stelodoryx.