Meeting Abstract

S8-2.1  Sunday, Jan. 6  “Don’t judge a book by its cover: Discovering two new Verongida genera (Class Demospongiae, Porifera)” DIAZ, M.C.*; THACKER, R.W.T; REDMOND, N.; COLLINS, A.G; Museo Marino, NE, Venezuela; U. Alabama at Birmingham, USA; NMNH, Smithsonian Institution, USA; NMNH, Smithsonian Institution, USA

Integrating morphological and molecular data is crucial when morphological characters are absent, or poorly represented, requiring genetic evidence to discern species identity and relationships. Among hundreds of specimens collected by the PorTol project were two morphospecies lacking any evidence of skeletal elements, one from Panama, the other from Moorea. Histological and molecular (18S) evidence were gathered to identify them. Histological sections of the Panama material corroborated the absence of any skeleton, and showed the existence of large, sac-shaped choanocyte chambers. The 18S analysis revealed that this species is allied with members of Ianthellidae (Verongida), which includes three genera with a total of 19 species, none present in the Caribbean. This species has a sister group relationship to a clade containing the skeleton-bearing Ianthellidae (Ianthella and Anomoianthella), while the third askeletal genus Hexadella is placed as a separate clade. This phylogenetic information supports the erection of a fourth genus for this family. Histological sections of the Moorea material revealed representatives of three genera among the samples initially considered to represent a single species. One showed the presence of amorphous, pith-dominated fibers (Pseudoceratina cf. purpurea) and another showed the existence of rare single fibers with pith and bark (Suberea sp.). A third species represents another askeletal genus of Verongida, placed within a clade of Aplysinellidae and Pseudoceratiniidae by 18S analyses. These findings demonstrate the importance of complementing the histology of askeletal sponges with genetic information that can clarify the real affinities and/or identities of the taxa.