An unusual new gorgonian coral (Anthozoa: Octocorallia) from the Aleutian Islands, Alaska

Despite the abundance and ecological importance of octocorals in Alaskan waters, most of the species in this assemblage remain unidentified and/or undescribed. One of the largest and most abundant species from the Aleutian Islands found at depths ranging between 125 and 512 m is a new and very unusual gorgonian coral. It has stout upright colonies that are laterally branched, with thick, more or less clavate terminal branches. Its major distinguishing characteristic is its possession of tiny sclerites with stubby double heads, which occur in the outermost coenenchyme. Another significant character is its oval capstans with elaborate ornamentation. The gorgonian is described as Alaskagorgia aleutiana new genus and species (Cnidaria: Octocorallia: Holaxonia: Plexauridae). It is described and assigned to Plexauridae because of the affinity of DNA sequences (1337 bp mtDNA: ND2 and MSH1) of A. aleutiana with other plexaurid corals, even though the predominant coenenchymal sclerites are somewhat smaller and different than is usual in plexaurid genera.