Lumbriclymenella sp. 1
Vouchers. VINSON WEST: station 5MFA.
Diagnosis. Large species; voucher complete; slightly desiccated specimen; 38mm long and 1.2mm wide for 19 chaetigers; colour in alcohol pale yellow; tube partially preserved.
Prostomium fused with peristomium; without cephalic plaque; with high cephalic keel; prostomium narrow, elongated, anteriorly rounded; nuchal slit, deeply curved; separated from the first chaetiger by an indistinct segmental furrow; followed by further two indistinct annuli. Chaetigers longer than wide, except for posteriormost chaetigers, which are about as long as wide; all segmentation relatively indistinct, with very shallow segmental furrows; chaetigers 1-3 biannulate.
Notochaetae of two types; long, thick and smooth bilimbate chateae (about 5 per fascicle in anterior chaetigers) and short to long, slender, distally hirstue chaetae (about 10 per fascicle in anterior chaetigers). Uncini from chaetiger 1; in chaetigers 1- 4 as one or two large, stout, blunt, honey-coloured spines; from chaetiger 5 as rostrate hooks, each hook has a large main fang surmounted by 3 smaller teeth; few (about 2) slender fibrilis and small swelling below the main fang present, handle long, up to 8 hooks per fascicle present in mid-body segments, reduced to 4 hooks in the last chaetiger.
Posterior part (posteriormost chaetigers and pre-anal achaetigerous segments) inflated (damaged, artefact of preservation?) and not clearly segmented, exact number of pre-anal segments difficult to establish; abruptly narrowing into short, slender, pygidial cone. Pygidial cone dorsally, with small, overhanging, rounded flap.
Tube soft (easy to open); internally as a soft muddy lattice; externally adorned with tightly packed, coarse, medium size particles, mostly black and white, giving speckled appearance.
Remarks. This species is represented by a single, but complete specimen in Falkland Islands collection. Only one species in genus Lumbriclymenella (no species in similar genus Lumbriclymene) is known from the region. Lumbriclymenella robusta Arwidsson, 1911 [type locality: South Georgia, depth 75m; subsequently reported form Falkland Islands by Fauvel, (1916)] agrees in possessing 19 chaetigers. However the following differences from L. robustawere are noted (based on images accompanying description of Arwidsoon in Hartman (1966): no red pigmentation of anterior end; hooks with swelling below the main fang, with fibrils (altough some hooks may lack fibrils); posterior end inflated and not distinctly segmented (this may be artefact of preservation).
Deep-sea species Lumbriclymenella nasuta (Wesenberg-Lund, 1948; type locality Greenland, 2258 m) has been recently re-described by Kongsgrud et al. (2013) and it is also very similar to both L. robustaand Falkland Islands specimens. More specimens from Falkland Islands need to be collected and compared with type specimens of other Lumbriclymenella species to establish if these represent a new species.