A new species of Pisione (Annelida, Sigalionidae) from Palk Bay, India

Abstract Pisione Grube, 1857 was considered rare animals, but its numbers have increased in recent decades. New species have been described, mainly from the Indo-Pacific region. In this study, we described Pisione balasubramaniani sp. nov., from Tamil Nadu, southeastern coast of India. The new species resembles other species in the ‘remota complex’ in the shape of the copulatory organs, elongated ventral cirri on the first segment and a short dorsal cirrus on the second segment. It can be distinguished from members of this group by having protruding notoacicula from the anteriormost to the very last chaetigers, three pairs of copulatory organs on chaetigers 15–17 and variances in the morphology of the copulatory organ. We also provide an updated comparison between all known species of Pisione based on key morphological characters. We also present a discussion of species of this genus in India and nearby regions.