Update on the distribution of Isaurus tuberculatus Gray, 1828 (Cnidaria, Zoantharia) and first insight into the microanatomy and cnidom of South Atlantic populations

The zoantharian Isaurus tuberculatus Gray, 1828 is highly variable in its morphology, and considered pantropical. As it is a shallow water and zooxanthellate species, its wide distribution has been questioned, and it is likely that the Atlantic and Indo-Pacific populations are distinct species. Here we update the distribution of this species in Brazil and provide the first description of the microanatomy and cnidom of populations in the South Atlantic. Along the Brazilian coast, the species is distributed from Ceará to Bahia, and is also in the Fernando de Noronha archipelago.