Description of four new species of Acromegalomma (Annelida, Sabellidae) from the Coast of Brazil (SW Atlantic), with comments on the morphological characters of the genus

Members of the genus Acromegalomma Gil & Nishi, 2017, of family Sabellidae, are characterized by the presence of subdistal compound eyes on the radioles. To date, 38 valid species of this genus have been recognized worldwide, including four species previously recorded in Brazil. In this study, we reviewed some of these records and identified four species new to science: A. josei sp. nov., A. omenae sp. nov., A. punctum sp. nov. and A. scutolenis sp. nov.

These findings are based on material from various independent expeditions, conducted between 1999 and 2023, along the Brazilian coast. A discussion on the key diagnostic features of members of these species and a comparative table of the morphological characters are provided, together with their formal descriptions and comparisons with the most morphologically similar congeners. Finally, a key for the identification of members of all species of Acromegalomma described from the Atlantic Ocean and South America is provided.