Phyllodocinae Örsted, 1843
Paranaitis Southern, 1914
Paranaitis sp. 1
Voucher. SEA LION: station 6MFA.
Diagnosis. Small, but relatively robust species; voucher specimen complete; 9mm long and 0.6mm wide for 64 chaetigers; preserved specimen yellow without any marked pigmentation.
Prostomium low, much wider than long (widest posteriorly), posterior margin poorly distinguished, anteriorly rounded; with 2 pairs of rudimentary prostomial appeandages (pair of antennae and pair of palps); eyes absent. Nuchal papilla not observed, ligula not observed. Proboscis not observed.
Segments 1 and 2 dorsally fused, not clearly set of prostomium dorsally. Four pairs of tentacular cirri in 1+2+1 arrangement, with 1st pair missing (scar observed); following pair of cirri with dorsal cirrus twice the length of ventral cirrus, reaching to segment 7; fourth pair similarly long.
Dorsal cirri foliose, elongated, with symmetrical rounded margin. Ventral cirri similar to dorsal cirri, but smaller. Chaetigerous lobes, narrow, conical, slightly assymetrical, with one acicula and about 8 chaetae per fascicle. Chaetae compound spinigers, with slender unidentate blades with thin tips; rostrum of chaetal shaft asymmetrical, with a main tooth and series of very fine serrations. Pygidium simple, wide, rounded lobe, no cirri observed (assumed missing).
Remarks. This species has a rather distinct look, due to fusion of first two segments with prostomium. It strongly resembles genus Chaetoparia, but no chaetae were observed on ventrum of segment 4. Similar fusion is also known in genus Paranaitis, which also lack median antenna and possess 4 pairs of tentacular cirri and nuchal papillae and chaetae on segment 3 may be absent, as it is the case in Falkland Island specimen. Although only one specimen was collected, it is in a good condition and complete, although anal cirri are likely missing. Specimen was stained using Shirla-stain in order to determine the presence of median antenna/nuchal papilla/ligula and these were not observed. However, a greater number of specimens would be preferable to check for consistency of these characters, which would suggest a new species in this genus.
