On Two Species Of Periclimenaeus Borradaile, 1915 (Caridea: Palaemonidae) From Colonial Tunicates In The Southwestern Atlantic

Two species of the palaemonid genus Periclimenaeus Borradaile, 1915, P. ascidiarum Holthuis, 1951 and P. maxillulidens (Schmitt, 1936), are reported from the offshore Escalvada Island, Espirito Santo, Brazil. The location represents a new southernmost record for these species in the western Atlantic. Both species were found inside an undescribed tunicate species of Diplosoma, dwelling inside the circulatory channels, among the zooid clusters. Although P. ascidiarum is known to occur in tunicates, the finding of the rare P. maxillulidens inside an ascidian host represents the first record of this association. Illustrations for both species and a taxonomic key for the southwestern Atlantic Periclimenaeus are provided based on the present material and literature records.