Diversity of pelagic tunicates (Appendicularia and Thaliacea) from Cuba: a review

Gelatinous zooplankton (GZ), and pelagic tunicates specifically, plays key roles in marine ecosystems, contributing to diets of various predators and oceanic carbon cycling. Nevertheless, biological inventories are often lacking, but are essential in establishing marine biodiversity baselines that, in turn, are critical in detecting broad-scale changes. The use of social media in combination with scientific records provides a powerful tool to broaden the scope of biodiversity studies. This study assesses the diversity of pelagic tunicates (appendicularians and thaliaceans) in the Cuban Exclusive Economic Zone (EEZ) and whether the EEZ acts as an ecotone between the Gulf of Mexico (GoM) and the Caribbean Sea (CS). By reviewing the scientific literature and using citizen science data, a total of 28 species were identified. The most diverse family among the appendicularians was Oikopleuridae (9 species) and among the thaliaceans Salpidae (6 species). Cuba’s northern EEZ was more speciose compared to the southern EEZ, 18 versus 14 species. No endemic species were found in Cuba’s waters and tunicate assemblages were most similar to the GoM. Our data do not support that Cuban waters act as an ecotone (for pelagic tunicates) between the GoM and CS faunas. The study highlights the importance of these GZ in marine food webs and their scarce knowledge in the region. Further long-term studies are required to understand spatiotemporal patterns and ecological roles of tunicates in Cuban ecosystems.