Contribution to the knowledge of freshwater sponges (Porifera: Spongillidae) from temporary water bodies of Costa Rica

Between 2017 and 2018 we carried out a limnological survey of 30 temporary water bodies in Costa Rica. Among other organisms, we studied freshwater sponges (Porifera: Spongillidae), on which this study is focused. We collected 15 552 sponge gemmules from 21 localities in the province of Guanacaste. This material was obtained throughout six sampling campaigns carried out between May 2017 and December 2018. The sponge species identified were Radiospongilla crateriformis (Potts, 1882), Corvoheteromeyenia heterosclera (Ezcurra de Drago, 1974), Tubella variabilis Bonetto & Ezcurra de Drago, 1973 and Ephydatia fluviatilis (Linnaeus, 1759), including new localities. The four species were collected together in a pond called "El Sitio", and this site, together with "Sainalosa" are also two new localities for T. variabilis, found together with Ephydatia fluviatilis and Corvoheteromeyenia heterosclera in the latter locality, both ponds located in the province of Guanacaste. In addition, it is remarkable the finding of T. variabilis gemmules agglutinated over the housing tube of the oligochaete Aulophorus vagus Leidy, 1880, (Annelida: Oligochaeta: Naididae). All gemmules were collected only on the Pacific slope of Costa Rica, while we did not find any in the ponds sampled on the Atlantic slope, possibly related to the higher phytoplankton concentration in the former, and the higher water transparency and lower salt content in the latter.