Paraliparis pearcyi, Stein, David L., 2012

Stein, David L., 2012, A Review of the Snailfishes (Liparidae, Scorpaeniformes) of New Zealand, Including Descriptions of a New Genus and Sixteen New Species, Zootaxa 3588, pp. 1-54 : 27-29

Paraliparis pearcyi n. sp.

Figs. 21 , 22

Holotype. NMNZ P.027142, female, 117 mm SL, 129 mm TL, 44°50.62' S, 175°29.45' E, Chatham Rise, R/V James Cook, Stn. JCO 9015/005, 20 September 1990, 1044– 1050 m. NMNZ P.027142/1, cleared and stained right pectoral girdle.

Diagnosis. Vertebrae 67, pectoral fin rays 20, rudimentary rays absent, caudal fin rays 8. Radials 3+0. Gill opening above pectoral fin. Mandible-anus 13% SL, 72% HL, preanal fin 38% SL, anus-anal fin 28% SL, 156% HL, chin pores widely separated, not in a pit.

Description. Counts. V 67, D 59, A 56, C 8, P 20, radials 3, pc 6. Ratios. HL 18.0% SL, HW 13.5, HD ~15.8, sn 4.3, E 5.2, orbit 6.7, io 3.5, uj 8.5, go 4.0, UPL 13.6, LPL 8.3, bd 21.9, preD 24.8, preA 38.5, sna 15.6, ma 13.0, aAf 28.1. In % HL: HW 74.9, sn 23.7, E 28.9, orbit 37.0, io 19.4, uj 46.9, go 22.3, UPL 75.3, LPL 46.0, bd 121.3, preD 137.4, preA 213.3, sna 86.7, ma 72.0, aAf 155.9.

Head less than 1/5 SL, dorsal profile sloping evenly to blunt, almost vertical, deep snout. Nostrils single, not tubular, on horizontal through center of eye. Mouth horizontal, terminal, oral cleft short, its posterior end below anterior margin of orbit; upper jaw reaching to below mid eye. Larger teeth clearly shouldered but not lobed, with sharp center cusp. Smaller teeth not shouldered, blunter than larger teeth. Teeth nearer symphysis larger with better developed shoulders. Premaxillary teeth in about 26 oblique rows of up to 13 teeth each, forming moderately wide band; lower jaw teeth in about 28 oblique rows of up to 10 teeth each. Both jaws with symphyseal tooth gaps, but in lower jaw, gap distinctly narrower. Eye relatively large, prominent, dorsal margin of orbit not entering dorsal profile of head and well below it. Gill opening completely above pectoral base, opercular flap small, supported by the dorsally curved opercle. Pores damaged, pattern and number not discernible; chin pores small, lacking raised or thickened rims, widely separated, not in a pit. Remaining pores very difficult to find, similar to chin pores in appearance.

Pectoral fin divided into lobes by moderately deep notch. Dorsalmost ray about on or above a horizontal through lower margin of orbit. Upper lobe about 3/4 HL, lower lobe much shorter, about half HL. Upper lobe not nearly reaching anal fin origin, lower lobe reaching to below base of uppermost pectoral ray. Pectoral rays 14+3+3, rays of notch much more widely spaced than in upper or lower lobes. Base of anteriormost lower lobe ray slightly behind vertical through posterior margin of orbit. Right pectoral girdle with 3 (3+0) round, unnotched radials. Scapula double headed, relatively long. Coracoid unusually long and slender, a broad basal notch present.

Body generally slender, tapering evenly from above abdominal cavity to caudal. Deepest point of body about at mid-abdomen. Trunk distinctly deeper than head, about 1/4 SL, even after removal of egg masses that greatly deepened abdomen. Abdomen unusually deep; peritoneum and body cavity extending dorsally to a horizontal through dorsal edge of eye. Vertebrae 9+58. Predorsal length about 1/4 SL, dorsal fin origin between vertebrae 5–6, anal fin origin between vertebrae 11–12. Preanal fin length about 2/5 SL. Posterior of dorsal and anal fins much deeper than anterior portions. Anus located below or slightly behind a vertical through posterior edge of orbit, between lower pectoral fin lobes. Pyloric caeca six, long, thick, digitate, located both left and right ventrally on stomach. Hypural fused, no slit evident, caudal fin of 4/4 rays. Skin translucent, thin, fragile.

Fresh color dusky, black peritoneum showing through body wall; posteriormost parts of dorsal and anal fins and entire caudal fin blackish. In alcohol, body color pale brown, with scattered melanophores; head and edges of dorsal and anal fins darker. Orobranchial cavity dusky. Peritoneum black, stomach and pyloric caeca pale. The specimen has ripe 2.2 mm eggs present in two large masses.

Distribution. Known from a single specimen collected on the Chatham Rise east of New Zealand, at a depth of about 1050 m.

Etymology. Named after William G. Pearcy, nekton ecologist and naturalist par excellence, for his exemplary research on, long standing interest in, and support for, deep sea biology.

Comparisons. A member of Andriashev's (2003: 220) “long tailed” Paraliparis , the new species is similar to Paraliparis duhameli Andriashev 1994 , from which it differs in lacking rudimentary pectoral fin notch rays (absent vs 2–3 present), number of pectoral fin rays (20 vs 25), pyloric caeca color (pale vs black), anus-anal fin distance (28 vs 20% SL), and other characters. It is similar to P. gracilis Norman 1930 in most counts and proportions, but has more pectoral fin rays (20 vs 15–17), longer gill opening (22 vs 15–20% HL), shorter upper and lower pectoral fin lobes (14 and 8 vs 17–22% SL for both), longer anus-anal fin length (28 vs 16–20% SL), and longer preanal fin length (38 vs 29–31% SL). It is also similar to P. leucoglossus Andriashev 1986 in number of vertebrae, pectoral rays, and caudal rays, but differs clearly from it in number of radials (3 vs 4), shorter head (18 vs 21% SL), shorter gill opening (above pectoral vs above and in front of 5–6 rays), greater predorsal length (24 vs 20% SL), and much more anterior anus (mandible-anus distance 13 vs 18% SL).

Paraliparis pearcyi differs from all the Australian Paraliparis species with three radials (see Stein et al. 2001) in having a narrower interorbital space (4 vs 6–9% SL, 19 vs 30–48% HL), a broader head (13 vs less than 10–13% SL, 75 vs 54–66% HL), a shorter snout (24% vs 31–38% HL), and from eight of the 13 species in having chin pores not in a pit or with an anterior skin fold.

Comments. The pectoral girdle of P. pearcyi is unusual in several regards. It may be the only Paraliparis with three radials but without R4, and its coracoid is extremely long relative to its width. Andriashev (2003, fig. 4) illustrated his hypothetical scheme of reduction in which P. trunovi represents the end stage with 2+0+0 radials, and P. neelovi Andriashev 1982 (with 2+0+1) radials represents the penultimate stage. Although P. pearcyi fits somewhere in this scheme, it’s unclear exactly where it would be. If this is an anomaly, the radial arrangement is a “regular” one (loss of the ventralmost radial) as opposed to others suggested by Andriashev (2003: 11) such as 1+0+1+1, 0+1+1+1, 0+0+1+0, and others. Even if the radial number and pattern are anomalous, this species is unique in its combination of other characters.

Figures

FIGURE 21. Paraliparis pearcyi n. sp. Holotype. NMNZ P. 027142, 117 mm SL. A. lateral view; B. NMNZ P. 027142 / 1, right pectoral girdle.

FIGURE 22. Paraliparis pearcyi n. sp. Holotype. NMNZ P. 027142, 117 mm SL. Lateral view of fresh specimen. (Photo by P. McMillan, NIWA)