Notoraja fijiensis, Séret & Last, 2012

Séret, Bernard & Last, Peter R., 2012, New deep water skates of the genus Notoraja Ishiyama, 1958 (Rajoidei, Arhynchobatidae) from the southwest Pacific, Zoosystema 34 (2), pp. 319-341 : 332-335

Notoraja fijiensis n. sp.

( Figs 13-15 ; Tables 2, 3)

HOLOTYPE. — MNHN 1999-0450 , female 386 mm TL, cruise MUSORSTOM 10, R / V Alis , Fiji, stn CP1312,

17°24.52’S, 178°34.00’E, 660/ 666 m depth, beam trawl, 5.VIII.1998.

PARATYPES. — 3 specimens. MNHN 1999-0452, immature male 307 mm TL, cruise MUSORSTOM 10, R / V Alis, Fiji, stn CP1337, 17°3.44’S, 178°47.21’E, 635/ 670 m depth, beam trawl, 9.VIII.1998. — MNHN 1999-0453, female juvenile 217 mm TL, cruise MUSORSTOM 10, R / V Alis, Fiji, stn CP1337, 17°3.44’S, 178°47.21’E, 635/ 670 m depth, beam trawl, 9.VIII.1998. — MNHN 1999-0451, immature male 212 mm TL, cruise MU- SORSTOM 10, R / V Alis, Fiji, stn CP1330, 17°9.50’S, 178°56.32’E, 567/ 699 m depth, beam trawl, 8.VIII.1998.

DISTRIBUTION. — Known from the slope of the Fiji Islands, between 567 and 699 m depth ( Fig. 18 ).

ETYMOLOGY. — Based on the Fiji Islands where the type specimens were collected.

DIAGNOSIS. — A species of Notoraja (probably of medium size) with the following combination of characters: a small but conspicuous preorbital thorn; dorsal surface of disc entirely velvety, covered with fine denticles; ventral surface velvety with widely spaced and very fine denticles; tail long and slender, entirely velvety, without enlarged thorns; lateral tail folds not expanded distally, narrower than tail for their whole length; nasal lobes not greatly expanded, width of nasal curtain 7.3-8.3% TL; mouth relatively small, its width more than 66% of maximum width of nasal curtain and 5.7-6.2% TL; anterior pelvic-fin lobe shorter that posterior lobe; dorsal surfaces plain pale yellowish brown, ventral surface creamy white; total pectoral-fin radials 64-66, monospondylous centra 25, total diplospondylous centra 119-127, total number of centra 144-152.

DESCRIPTION

Disc heart-shaped, 1.18 times as broad as long in holotype (1.11-1.16 in paratypes); maximum angle in front of spiracles 98° (91-98°); anterior margin weakly undulate, slightly concave on either side of tip of snout, convex from anterior extension of propterygium to anterior margin of orbit, concave to level of spiracle; outer corner broadly rounded; posterolateral margin moderately convex. Axis of greatest width 56% (53-60%) of disc length. Preorbital snout length 2.56 (2.48-3.26) times orbit length, 3.55 (3.35-3.90) times interorbital width; preoral snout length 1.86 (1.97-2.13) times internarial distance. Orbit diameter 1.39 (1.20-1.35) times interorbital distance, 2.02 (1.96-3.11) times length of spiracles. Nasal lobes not greatly expanded and rounded; posterior margin shortly and flabby fringed. Mouth small, its width more than 66% of maximum width of nasal curtain. Upper and lower jaws weakly arched.Teeth plate-like, with short cusps; arranged in quincunx in female holotype and juveniles paratypes. Distance between first gill slits 1.86 (1.63-1.70) times longer than distance between nostrils; distance between fifth gill slits 1.23 (0.91- 1.10) times longer than distance between nostrils. Pelvic fins deeply incised with lobes connected by radials and membranes; anterior lobe moderately long, slightly shorter than posterior lobe in holotype (longer than posterior lobe in paratypes), finger-like, tapering to blunt point distally; posterior lobe with convex lateral margins. Tail narrow at base, oval, depressed slightly, tapering gradually posteriorly; very convex dorsally, weakly convex ventrally; tail width at axil of pelvic fin 2.43 (2.00) times width at midlength of tail, and 2.51 (2.53-2.77) times width at dorsal-fin origin respectively; length from rear of cloaca 1.28 (1.37-1.43) times distance from tip of snout to rear of cloaca; width 1.52 (1.36- 1.51) times height at axil of pelvic fin; width at first dorsal-fin origin 2.03 times height (1.39-1.44); lateral skin folds originating near anterior third of tail, extending to distal third of epichordal caudalfin lobe and broadening distally; fold width always less than tail width. Dorsal fins of similar shape and size; moderately tall, flag-like with evenly convex anterior margin, slightly convex posterior margin and a pointed tip; separated by very short interspace, 10.4% (4.0-5.0%) length of first dorsal-fin base. Epichordal caudal-fin lobe well developed, separated by short interspace from the second dorsal fin, slightly longer than second dorsal-fin base; hypochordal caudal lobe very low, originating near end of lateral fold, confluent with epichordal lobe.

Dorsal surface entirely covered with fine, bristlelike dermal denticles, with conical bases; denticles partly embedded in skin; crown exposed, erect, slightly curved. Ventral surface less well covered with tiny, very widely spaced denticles (smallest paratypes almost naked), their shape similar to those of dorsal surface; belly and pelvic fins mostly devoid of denticles.A conspicuous preorbital thorn. Dorsal and ventral surfaces of tail velvety; dorsal mid line without obvious thorn, instead with an irregular row of slightly enlarged denticles. Malar and alar thorns not developed in female and juvenile male types.

Tooth rows in upper jaw 32 in holotype (37-38 in paratypes); lower jaw 35 (38-40). Pectoral propterygial radials 29-30 (29); mesopterygial radials 11-12 (11-12); metapterygial radials 23 (23-25); total radials 64 (64-66). Monospondylous centra 25 (25); diplospondylous predorsal centra 80 (77-81); predorsal centra 105 (102-106); caudal centra 41 (38-44); total diplospondylous centra 121 (119- 127); total centra 146 (144-152).

Colour (in preservative)

Dorsal surface plain pale yellowish brown, outer disc margin paler; eyes greyish; midline of tail dusky; dorsal and caudal fins dusky with darker edges; ventral surface of disc and tail creamy white.

Size

Reaches at least 395 mm TL based on the female holotype; a male of 310 mm TL was still immature.

REMARKS Notoraja fijiensis n. sp. is distinguishable from N. alisae n. sp. by its much paler colouration, being pale yellowish brown dorsally (rather than pale greyish brown) and whitish ventrally (rather than dusky yellow), shorter denticles on the dorsal disc, relatively broader predorsal tail, and having larger much darker dorsal fins. Also, it has a more obvious heart-shaped disc with a weakly undulate anterior margin, and its preorbital thorns are more conspicuous.

Figures

FIG. 13. — Notoraja fijiensis n. sp., holotype (MNHN 1999-0450, female 386 mm TL): A, dorsal surface; B, ventral surface. Scale bar: 10 cm.

FIG. 14.— Dorsal head of Notoraja fijiensis n. sp.,holotype (MNHN 1999-0450, female 386 mm TL). Scale bar: 1 cm.

FIG. 18.— Oronasal region of Notoraja longiventralis n.sp., holotype (MNHN 1999-0449, male juvenile 434 mm TL). Scale bar: 1 cm.