Associated organisms inhabiting the calcareous sponge Clathrina lutea in La Parguera, Puerto Rico

Sponges provide an array of ecological services and benefits for Caribbean coral reefs. They function as habitats for a bewildering variety of species, however limited attention has been paid in the systematics and distribution of sponge-associated fauna in the class Calcarea or for that matter of sponges in the Caribbean. The goal of this study was to characterize infaunal assemblages from a calcareous sponge, Clathrina lutea, across multiple reefs from the La Parguera Natural Reserve, Puerto Rico. A total of 2,249 ecto- and endosymbiont organisms were recovered from 43 specimens of the calcareous sponge Clathrina lutea. These associated organisms were distributed across seven invertebrate phyla, with Arthropoda (62.5%) being the most abundant, followed by Annelida (21.0%), and Nematoda (5.5%). Limited patterns of temporal or spatial variability were surmised due to the opportunistic sampling effort afforded to this investigation from the cryptic nature of this species. A concordance between our data set and those for the class Demospongiae were observed, with the most abundant groups being copepods and polychaetes. However, when compared to the other few studies looking into the associated fauna of calcareous sponges, this species (Clathrina lutea), yielded a considerable high number of diversity and abundance of associated fauna, hinting at its ecological importance to maintain cryptic biodiversity.