Paraliparis alius, Stein, 2012

Stein, David L., 2012, Snailfishes (Family Liparidae) of the Ross Sea, Antarctica, and Closely Adjacent Waters 3285, Zootaxa 3285, pp. 1-120 : 28-29

Paraliparis alius n. sp.

Figs. 16, 17, 18

Holotype. NMNZ P.042623, female, 330 mm TL, 299 mm SL, 70°29.80' S, 179°07.60' E, SW of Iselin Seamount , F/ V San Aotea II, Stn. OBS 2332/106, 27 January 2007, 1225– 1332m. NMNZ P.042623/1, cleared and stained right pectoral girdle.

Diagnosis. V 71, A 57, C 6, P 20, radials 4 (3+1). Pectoral fin notch rays rudimentary. Teeth mostly uniserial, eye 22% HL, interorbital about 40% HL, 6% SL. Gill opening 14% HL, 2% SL. Opercular flap present, small, triangular. Dorsal fin insertion between V 6–7. Preanal fin length 46% SL, lower pectoral lobe distance 16% HL. Longest pyloric caeca flattened, thin-walled, 60% HL or longer. Body color pale purplish, mouth pale dusky.

Description. Counts. V 71 (11+60), D 63, A 57, C 6, P 20 (14+2–3+3–4), radials 4, pc 6, pore formula unknown. Ratios. HL 16.2, HW 12.4, sn 4.9, E 3.6, orbit 4.6, io 6.4, uj 6.0, go 2.3, preD 28.2, preA 45.7, sna 17.7, ma 15.0, aAf 28.2, UPL 12.0, LPL 12.3, pcl 10.2. In % HL: HW 76.6, sn 30.2, E 22.1, orbit 28.3, io 39.9, uj 37.2, go 14.0, preD 174.0, preA 282.2, sna 109.3, ma 92.8, aAf 174.0, UPL 74.0, LPL 76.2, LLD 16.3, cp 3.1, pcl 63.2.

Head small, about 1/6 SL, low, dorsal profile rising evenly from snout through flat interorbital region to above proximal end of opercle. Snout short, low, bluntly rounded, projecting slightly beyond upper jaw. Nostrils with raised rim, on horizontal through mid-orbit and spaced anterior to it. Mouth barely subterminal; lower jaw clearly included, oral cleft barely reaching to below anteriormost margin of orbit. Premaxillary teeth consist of about 35 simple, conical, sharp, evenly spaced canines, arranged uniserially for about 80% of jaw length, then irregularly bi- or tri-serial for remaining distance to wide gap at symphysis. Mandibular teeth tiny, in a row of at least 60, closely spaced, forming a sharp cutting edge along jaw; anteriormost teeth much smaller and difficult to see. Eye prominent, orbit slightly more than ¼ head length, not quite entering dorsal profile of head. Gill opening entirely above pectoral fin base; opercular flap a short obtuse triangle, supported by dorsally curved opercle, its tip slightly lower than its hyomandibular attachment joint, clearly not reaching posteriorly to base of pectoral fin. Pores of mandibular series appear to be of equal size, rims pale, thickened. Chin pores damaged, closely paired, possibly with anterior skin fold but more likely without; their distance apart about 3% of head, near lower lip. Suprabranchial pore single.

Pectoral fins shorter than head, upper lobe not reaching midpoint of abdominal cavity, about half distance to anal fin origin. Uppermost ray even with or slightly above lower margin of orbit. Upper lobe possibly sharp-tipped, of 14 rays. Notch rays 2–3, right side fin with two rudimentary notch rays, uppermost short, filamentous, lacking segmentation; lower reduced to base only. Lower lobe long, of 3–4 rays, the longest not reaching to below tip of upper lobe; insertion of lowest ray below or slightly anterior to proximal end of opercle. Distance between lower fin lobes wide, about 16% head. Right pectoral girdle with 4 (3+1) large, round, closely and almost evenly spaced radials of similar size, R3-R4 space short, about twice that between more dorsal radial pairs; no notches or slits present. Radial R1 largest, R3 distinctly smallest. Scapula double-headed with long helve. Coracoid with unusually long slender helve, ventral notch absent.

Body behind head dorsoventrally flattened, deepest well behind head over mid- abdomen. Postcleithrum prominent, extending posteroventrally at about 45 degree angle from above tip of opercle to about level of oral cleft, ending bluntly in abdominal wall. Dorsal fin insertion between vertebrae 6–7, anal fin insertion between vertebrae 12–13. Dorsal and anal fins very low, with short rays anteriorly, becoming much more prominent at about 40% SL; deepest points and longest rays at about 2/3 SL. Anus on vertical behind opercle tip, below or slightly posterior to upper base of pectoral fin lobe. Peritoneum clearly visible through whitish body wall. Body cavity long and deep, its dorsal outline about level with upper margin of orbit. Hypural complex fused, slit absent. Caudal fin of six (3/3) rays, auxiliary rays absent. Pyloric caeca six, in two groups of three; those of one group are long, flattened and thinwalled (the longest about 60% head length); in other group, caeca plump, digitate, thick-walled, half as long or shorter. SECM probably well developed. Skin thin but not easily torn, very loose, hanging in folds, presumably from loss of SECM during capture and preservation.

Color of fresh specimen translucent white, dorsal and anal fins with blackish edges, snout and interorbital area dusky; peritoneum clearly visible, black through body wall and skin (Fig. 17). Color of body in alcohol pale rosy, snout and area around mouth dusky brown, skin on tail same as anteriorly, dorsal and anal fins brown edged. Mouth dusky pale, branchial cavity blackish, stomach and pyloric caeca pale.

This female has eggs up to 2.7 mm diameter.

Distribution. Known only from the holotype, collected SW of Iselin Seamount at depths of 1225–1332m.

Etymology. The name alius from the Latin alius , another, because this species differs from all others in its different combination of characters but has no outstanding particular trait.

Comparisons. Externally, Paraliparis alius is most similar to P. longicaecus (see below), the southern P. copei Goode & Bean 1896 group (see Andriashev 2003:252–261) and to P. neelovi in its counts, proportions, and mostly uniserial teeth. It differs from the second in having fewer caudal fin rays (6 vs 8), a smaller eye (22 vs 25–36% HL), more anal fin rays (57 vs 52–56), gill opening longer, with an opercular lobe, not porelike (14 vs less than 14% HL, porelike), and a more posterior anal fin distance (46 vs 33–40% SL). It differs from the last in the number of radials (4 vs 3), the distance between the lower pectoral lobes (16 vs 11% HL), dorsal fin insertion (between V 6–7 vs 4–6), and other characters.