Checklist of ascidians (Chordata, Tunicata) from the southern Gulf of Mexico

This study is the first inventory of ascidians from shallow waters (0–25 m) of coastal and reef habitats in the southern Gulf of Mexico where ascidian diversity is poorly known. Sampled environments in 14 locations (38 sites) with 134 samples collected from 2015 to 2017 included coral reefs, coastal lagoons, mangroves, seagrass, ports, and artificial platforms. The 31 identified species comprise 19 genera and 13 families. Ten species are newly reported in the Gulf of Mexico: Ascidia panamensis Bonnet & Rocha, 2011; Ecteinascidia styeloides (Traustedt, 1882); Cystodytes roseolus Hartmeyer, 1912; Eudistoma aff. amanitum Paiva & Rocha, 2018; Eudistoma recifense Millar, 1977; Euherdmania fasciculata Monniot, 1983; Euherdmania aff. vitrea Millar, 1961; Polycarpa cartilaginea (Sluiter, 1885); Botrylloides magnicoecum (Hartmeyer, 1912) and Didemnum granulatum Tokioka, 1954. Two new species will be described separately (Clavelina sp. and Pyura sp.). This study provides the first records for 26 species ascidians for the region as well as describes increased distributions of ten Atlantic species. Thus, our data provide a starting point for future ecological, experimental and taxonomic studies of ascidians of the Gulf of Mexico.