On the presence of Distichoptilum gracile Verrill, 1882 (Octocorallia: Pennatulacea), in the southeastern Pacific

Abstract

The two-lined sea pen Distichoptilum gracile Verrill, 1882, the type and only species that is considered valid in the genus Distichoptilum Verrill, 1882, is a rather large deep-water pennatulacean found in soft bottoms. Its deep red colonies are conspicuously long (1 m or more) and thin, with autozooids arranged alternately in simple rows on each side. This species has an almost cosmopolitan but fragmentary distribution, with sparse records from the Atlantic, Indian and Pacific Oceans. In the Pacific Ocean, its occurrence has been scarcely reported: from off Mexico, the Galapagos Archipelago and off New Zealand. The present record of this rare species is based on a collected colony that was entangled in a longline used in the fisheries of the Patagonian toothfish Dissostichus eleginoides Smitt, 1898, off Chañaral (26°S), Región de Atacama, along the continental margin of northern Chile. Distichoptilum gracile is the third species of the entire order Pennatulacea to be recorded in Chile, being also the first record of the family Protoptilidae Kölliker, 1872, and of the genus Distichoptilum Verrill, 1882 for Chile. The presence of this species confirms the need not only for further studies of the bycatch of commercial fisheries, but also for inventories to document the diversity of deep-water anthozoans in the southeastern Pacific.