Aetheliparis taurocanis, 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 : 6-7

Aetheliparis taurocanis n. sp.

Figs. 2 , 3

Holotype. NMNZ P.04515, female, 32 mm SL, TL unknown, 35°15.00' S, 176°15.00' E, near Moa Seamount, RNZFA Tui, Stn. AUZ 0 73, 22 July 1962, 731– 869 m.

Diagnosis. Mouth cleft vertical, lower margin of opercular flap horizontal. Coronal pore absent. Teeth thornlike or stout pyramidal canines, not lanceolate. Pectoral fin base far behind head and gill opening. Body short, vertebrae ~42, dorsal fin rays ~35, anal fin rays ~31. Interorbital width 9, mandible-anus 39, anus-anal fin 17, lower jaw 12% SL.

Description. Counts: V ~42, D ~35, A ~31, C 6, P 15, radials unknown, gr unknown, pc 5–6, pore formula unknown. Ratios: HL 30.6, HW 15.6, sn 6.9, E 5.9, orbit 7.2, uj 10.0, lj 11.6, po 17.8, io 8.7, bd 22.8, bdA 16.9, preD 31.2, preA 48.4, sna 37.5, ma 38.7, aAf 17.2. In % HL: HW 51.0, sn 22.4, E 19.4, orbit 23.5, uj 32.6, lj 37.8, po 58.2, io 28.6, bd 74.5, bdA 55.1, preD 102.0, preA 158.2, sna 122.4, ma 126.5, aAf 56.1.

Head about 1/3 SL, dorsal profile almost horizontal; snout short, not protruding anteriorly, covered by and posterior to symphysis of mandible. Nostrils single, nasal rosette almost touching anterodorsal margin of orbit, just above horizontal through dorsal margin of orbit. Mouth very large; when closed, lower jaw forms almost entire front of head, oral cleft vertical or almost vertical, symphysis of lower jaw reaching almost to level of dorsal profile of head. Teeth small, sharp, stout thorn-like canines, not lanceolate or blunt; uniserial for at least posterior half of upper jaw, forming a narrow band of irregularly arranged teeth anteriorly. Mandibular teeth stouter, more pyramidal in shape, forming a narrow band, much wider anteriorly near symphysis. Rows uncounted. Orbits large, eyes prominent, not quite entering dorsal profile of head. Interorbital space broad, 1.5 times eye diameter. Gill flap and openings completely anterior to margin of pectoral fin base. Opercle elongate, supporting enlarged branchial cavity and membrane. Gill opening membranous, hidden by opercular flap, relatively long, angled dorso-posteriorly, its ventral end above a horizontal through dorsal end of pectoral fin base. Lower part of branchial membrane of gill opening supported by branchiostegal rays 2, 3, and 4. Branchiostegal rays six, extremely long, clearly visible through skin, oriented horizontally, then curving posterodorsally. Cephalic sensory pores difficult to determine owing to fragility of skin and damage. Two nasal pores present; coronal apparently absent, io 1–5 present, t1 present but t2 apparently absent. Symphyseal pores relatively large, prominent, separated by a distance of 1 1/2–2 pore diameters, one either side of mandibular symphyseal knob. Other pores damaged or not found.

Pectoral fin upper ray about even with ventral margin of orbit. Fin base low on side of body, far behind head and gill opening and slightly anterior to a vertical through dorsal fin origin. Upper lobe of nine closely spaced rays, apparently deep notch including two normally developed rays distinctly more widely spaced, separated from upper and lower fin lobes, lower fin lobe of four closely set rays. Bases of lower lobe rays similar to those of upper lobe. Supracleithrum elongated posteriorly and slightly ventrally, possibly fused with or attached to cleithrum to form a long acutely triangular blade extending to post-temporal to support posteriorly located pectoral girdle. Pectoral girdle not examined.

Trunk of body not dorsally curved or humpbacked, abdominal spinal column straight. Body deepest at middle of abdominal cavity, at a point about 40% SL posterior to lower jaw symphysis. Vertebrae 8 or 9 + 33 or 34; in radiograph, first three neural spines appear distally unfused and forked. Dorsal fin origin far posterior, between vertebrae 5–6 or 6–7, slightly posterior to pectoral fin base and approximately above posterior end of abdominal cavity; origin of anal fin at vertebra 10–11. Preanal fin length slightly less than one half SL. Anus position far anterior to anal fin origin, below posterior edge of pectoral fin base, about 1 1/4 HL from mandibular symphysis. Abdomen swollen; distal portion of intestine strongly pigmented brown, more anterior portion pale except near stomach where it is brown. Stomach dorsal in body cavity, pyloric caeca 5–6, short, pyramidal. Hypural elements fused, caudal fin of six (3/3) rays, length unknown. Skin thin, translucent or transparent.

Color in life unknown. Body color in alcohol pale translucent tan, orobranchial cavity darker brown; peritoneum dark brown, visible through body wall; gastric and rectal portions of intestine brown, cream colored between. Stomach brown but pyloric caeca pale. The specimen has very small eggs.

Distribution. Known from a single specimen collected in midwater at bathypelagic depths near Moa Seamount, northeast of New Zealand.

Etymology. The specific epithet taurocanis from the Latin taurus, bull, and canis, dog, in reference to the pugnacious appearance of the fish resulting from its vertical mouth and prominent lower jaw.

Comparisons. The new species is remarkably similar to Aetheliparis rossi from the northwest Atlantic off Cape Hatteras, which it strongly resembles in its vertical mouth, absence of coronal pore and humped spine, peculiar gill opening and position, and posterior location of the pectoral fin girdle. However, it differs in having fewer vertebrae (42 vs 47), dorsal and anal fin rays (35 vs 42–44 and 31 vs 33–35 respectively), in tooth shape (pyramidal and thornlike vs lanceolate and slender, especially anteriorly), color of orobranchial cavity, tongue, and peritoneum (brown or tan vs black), and in many morphometric ratios, particularly the shorter lower jaw (38 vs 45–50% HL) and more anterior location of the anus (mandible-anus distance 23 vs 35–37% SL).

Figures

FIGURE 2. Aetheliparis taurocanis n. g. n. sp. Holotype. NMNZ P. 04515, 32 mm SL. Lateral view.

FIGURE 3. Aetheliparis taurocanis n. g. n. sp. Holotype. NMNZ P. 04515, female, 32 mm SL. A. Lateral view of preserved specimen. B. Lateral view of head and abdomen of preserved specimen. (Photos by C. Struthers, Te Papa)