Revision of Buskiella McIntosh, 1885 (including Flota Hartman, 1967), and description of its trifid organ (Polychaeta: Flotidae)

Abstract

The species included in both Buskiella McIntosh, 1885, and Flota Hartman, 1967 are revised on the basis of type and non-type materials, as well as on published accounts. Both genera are synonyms and the former has priority; the species included are B. abyssorum McIntosh, 1885, B. flabelligera (Hartman, 1967) comb.n., and B. vitjasi (Buzhinskaya, 1977) comb.n. Two other species previously included in the genus (B. borealis Hartman, 1965 and B. minuta Amoureux, 1986) are non-pelagic flabelligerids belonging elsewhere. The three Buskiella species are re-described, and an identification key is included. Further, the trifid organ is being described in details for the first time; this unique organ is neither a palp nor a branchial radiole. A similar structure has been reported in Paralvinella Desbruyиres & Laubier, 1982. The independent status of Flotidae has been challenged, but its oligomery (body with few segments), trifid organ, and nervous system are unique, so this status deserves to be retained.