Leaena Malmgren, 1866
Leaena? sp. 2
Voucher. VINSON WEST: station 1MFA.
Diagnosis. Voucher specimen very small and slender, complete, about 4mm long and 0.4mm wide for about 33 chaetigers. Body anteriorly somewhat dorsoventrally flattened. Segmental lobes absent. Branchiae absent. Eyes absent. Abdomen with about 22 uncinigers. Pygidium rounded lobe.
Eleven thoracic chaetigers. Notochaetae of 2 types – long, broadly bi-limbate and short lanceolate. Thoracic uncini present from chaetiger 2, first 6 uncinigers with uncini in a single row, from unciniger 7 arranged in double (alternating) row, until the end of the fragment.
Remarks. Generic assignment of these specimens is somewhat problematic as taxonomy of abranchiate terebellids lacks consistent characters. The combination of the following characters: absence of branchiae, presence of uncini from chaetiger 2 and presence of lanceolate notochaetae shows affinities with genus Leaena Malmgren, 1866. Genus Leaena appears to be well represented in the region. Number of thoracic chaetigers varies from 10-17 in different species. Further work would be necessary to establish if Falkland Island species represents a new species and name Leaena sp. 2 is assigned here provisionally.