Acanthotylotra Volkmer-Ribeiro, Tavares & Fürstenau-Oliveira, 2009

Pinheiro, Ulisses, Calheira, Ludimila, Martins, Celina, Janson, Liesl, Taylor, Ricky & Samaai, Toufiek, 2020, Two new species of freshwater sponges from Neotropical and Afrotropical Regions, Zootaxa 4728 (3), pp. 363-371 : 367

Genus Acanthotylotra Volkmer-Ribeiro, Tavares & Fürstenau-Oliveira, 2009

Restricted synonymy. Acanthotylotra Volkmer-Ribeiro, Tavares & Fürstenau-Oliveira, 2009: 346

Type species. Acanthotylotra alvarengai Volkmer-Ribeiro, Tavares & Fürstenau-Oliveira, 2009 (by subsequent designation).

Diagnosis. Sponge forming initial minute whitish tufts at the base of other sponges. Consistency firm. Skeleton a renieroid reticulation with scanty spongin cementing the extremities of the megascleres together at the reticular nodes. Megascleres in two categories. Primary megascleres thick, curved to straight acanthotylostrongyles, the curved ones with the concave section of the spicule smooth and the outer one spined. The spines grouped in small spots or forming half rings on the convex section of the spicule, the tylote extremities entirely covered with minute spines. Secondary megascleres slim, straight to slightly curved anisostrongyles presenting several irregularly distributed microspined tubercules along the spicule length except at the extremities, which are invariably covered with minute spines. Microscleres unknown or absent. Gemmules unknown. Adult sponge also unknown ( Volkmer-Ribeiro et al. 2009).

Remarks. Volkmer-Ribeiro et al. (2009) described Acanthotylotra , a monotypic genus, from the Neotropical Region ( Brazil) having acanthotylostrongyles as primary megascleres and acanthostrongyles as secondary ones, which supports a reticulate skeleton with scarce spongin. Microscleres and gemmules are unknown. Until now, the genus Acanthotylotra is considered incertae sedis within the Order Spongillida. This genus however, has a similar skeleton architecture as found in the Family Potamolepidae , and the spicule compliments are similar to that found in species of the genus Oncosclera Volkmer-Ribeiro, 1970 , Uruguaya Carter, 1881 , Potamophloios Brien, 1970 , Echinospongilla Manconi & Pronzato, 2002 and Potamolepis . Echinospongilla and Potamolepis species also lack microscleres and gemmules. Based on these morphological congruencies we propose to transfer the genus Acanthotylotra to the Family Potamolepidae .