Leptaulopus erythrozonatus, Gomon & Struthers & Stewart, 2013

Gomon, Martin F., Struthers, Carl D. & Stewart, Andrew L., 2013, A New Genus and Two New Species of the Family Aulopidae (Aulopiformes), Commonly Referred to as Aulopus, Flagfins, Sergeant Bakers or Threadsails, in Australasian Waters, Species Diversity 18, pp. 141-161 : 157-158

Leptaulopus erythrozonatus sp. nov.

[New English Name: Duckbill Flagfin] ( Figs 1 , 2C , 5C, D , 6 ; Table 2, 4)

Aulopodidae n. gen et n. sp.: Roberts et al. 2009: 530.

Holotype. NMNZ P.042518, 271 mm SL, 37°24.29′S, 176°24.83′E, Penguin Rise , Bay of Plenty, 130–140 m, 30 September 2006, R. Keyzer, rod and line.

Paratypes. 3 specimens, 186–274 mm SL. NEW ZEALAND: NMNZ P . 037704, 256 mm SL, 37°17.00′S, 176°25.00′E, 7 miles east of Mayor Island , 280 m, 22 April 2001, D . Brambley, rod and line; NMNZ P . 047334, 274 mm SL, 37°24.24′S, 176°24.69′E, Penguin Rises , Bay of Plenty, 135 m, 25 December 2009, R . Keyzer, rod and line. AUSTRALIA: AMS I. 40318–001, 186 mm SL, off Batemans Bay , New South Wales, 35°44.0′S, 150°13.0′E, 174–177 m, 1996, K . Graham on FV Salvatore V, demersal trawl .

Diagnosis. Dorsal fin rays 15 or 16; anal fin rays 10 or 11; vertebrae 26 or 27+17 or 18=44; lateral line scales 44+ 1; scales below lateral line 4.5; predorsal scales 20; gill rakers 3+12. Snout elongate, length 11.5–12.4% SL and 34.6– 36.5% HL, much longer than eye diameter, dorsoventrally flattened, narrowly rounded from above; bony interorbital narrow, width 3.0–3.5% SL and 8.9–10.3% HL; distance from snout tip to dorsal fin origin 42.5–43.7% SL and 128– 129% HL; anal fin base 9.2–9.8% SL and 27.0–29.1% HL. Expanded posterior end of maxilla and posterior and ventral margins of preopercle stark white. Dorsal fin translucent with four to six narrow submarginal stripes from base to outer edge of fin, those posteriorly angled obliquely, intervening spaces on fin rays white. Caudal fin white with four or five red bands crossing each lobe, proximal bands continuous across fin in some.

Description. Dorsal fin rays 16 (15 or 16); anal fin rays 11 (10 or 11); caudal fin rays 10+19+8; pectoral fin rays 12; pelvic fin rays 9; vertebrae 26+18=44 (27+17=44); lateral line scales 44+1; scales above lateral line 3.5; scales below lateral line 4.5; predorsal scales 20 (19–20); gill rakers 3+12 (2–3+12=14–15) (see Table 4 for morphometric values).

Body elongate, moderately thick, of similar breadth from eyes to posterior end of dorsal fin; dorsal profile of snout straight, nape with slight convex curve, inclined to dorsal fin origin, sloping more gradually to base of tail with straight dorsal profile; ventral profile of head and body mostly straight; caudal peduncle of moderate depth; body deepest at anterior part of dorsal fin, depth at dorsal fin origin 16.8 (18.0–19.3) % SL; depth at origin of adipose fin 10.8 (11.0–11.6) % SL; anus closer to anal-fin origin than pelvic-fin origin, length from anus to anal-fin origin 12.6 (12.5–14.3) % SL. Head moderately large, pointed; snout elongate, length 12.1 (11.5–12.4) % SL and 36.5 (34.6–36.4) % HL, much longer than eye diameter, dorsoventrally flattened, narrowly rounded from above; eye of moderate size, diameter 6.4 (6.5–7.2) % SL and 19.2 (19.1–21.7) % HL, top of eye jutting above dorsal profile of head; bony interorbital distinctly concave, narrow, interorbital width 3.2 (3.0–3.5) % SL and 9.7 (8.9–10.3) % HL; postorbital nearly half head length. Anterior nostril small, posterior nostril much larger, anteroposteriorly elongate, about three or four times diameter of anterior nostril, both about midway between tip of snout and orbit; fimbriate tabular skin flap based on septum separating nostrils ( Fig. 2C ). Edge of preopercle smooth, posterior margin straight, angle about 90°, blunt; opercular margin broadly curved; without well-developed membranous lobe; branchiostegal membranes overlapping ventrally, free from isthmus. Mouth of moderate size, terminal, lower jaw not projecting in advance of upper, profile of upper jaw hidden when viewed from above; posterior end of maxilla moderately broad, posterior margin nearly straight, extending just past vertical through centre of eye, dorsal margin separated by skin covered gap from underside of eye with mouth closed; upper lip broad, covering upper jaw laterally with mouth closed. Teeth in jaws very small, caniniform to cardiform, those of upper jaw in band of about four or five ill-defined rows laterally and six or seven ill-defined rows anteriorly, more or less of uniform size, smaller teeth on side of jaw near front, distinct hiatus of teeth at symphasis; band of seven or eight ill-defined rows of teeth laterally in lower jaw, band narrower in about four or five rows at front, inner row of noticeably larger teeth mesially; triangular naked hiatus in dentition at symphasis. Band of several rows of small canines on palatines and bilateral pair of dentate patch of teeth on vomer, interconnected by row of smaller teeth medially in large individuals. Gill rakers moderately long and slender.

Scales of moderate size, finely spiniform along margins, not extending onto fins, except caudal fin with small scales dorsally and ventrally at base; scales on breast cycloid to weakly spiniform. Predorsal scales extending forward to vertical through posterior extent of eye, covering opercle and preopercle forward to posterior end of maxilla; axial scale present at origin of pectoral and pelvic fins. Lateral line midlaterally on side, originating at horizontal through upper margin of eye; lateral line scales corresponding with oblique scale rows above and below lateral line; single pore on each lateral line scale.

Dorsal fin originating just behind vertical through pelvic fin origin, distance from snout tip to dorsal fin origin 42.6 (42.5–43.7) % SL; dorsal fin base moderately short, length 1.12–1.38 times distance from dorsal fin insertion to origin of adipose fin; third ray longest, rays progressively decreasing in length posteriorly; posterior lobe reaching little more than half way to hypural crease; first two dorsal-fin rays unbranched, others branched. Adipose fin rather small but prominent, positioned above posterior end of anal-fin base. Anal fin originating slightly in advance of vertical through midpoint between dorsal fin insertion and adipose fin, with short base, length 9.7 (9.2–9.8) % SL; of moderate depth, rays progressively decreasing in length posteriorly; posterior lobe reaching much less than half way to hypural crease; first two or three rays unbranched, others branched. Caudal fin with shallow fork, shortest rays at middle of fin about half length of longest rays extending to corners, lobes bluntly pointed, lobes of similar length; rays near ventral margin of fin more densely segmented than those near dorsal margin of fin; unbranched ray at ventral margin with opaque fleshy covering ventrally in large individuals. Pectoral fin of moderate size, length 15.8 (16.4–17.9) % SL, tip reaching vertical through middle of dorsal fin base; origin of fin well in advance of vertical through dorsal fin origin by distance equal to or greater than eye diameter; first two rays simple, others branched, third longest, subsequent rays progressively shorter. Pelvic fins moderately large, posterior tip of depressed fin reaching just past anus; first four rays distinctly thickened and cylindrical with fleshy dermal covering at least distally, densely segmented, first ray unbranched, second to fourth each with a pair of simple thickened branches, subsequent rays progressively shorter, flattened with typical multibranching, except for inner-most unbranched ray.

A species of moderate size, largest specimen examined 274 mm SL.

Colour of preserved specimens. Head and body blotched with dark, dusky and pale patches above level of pelvic fin base, uniformly pale below and behind edge of operculum on and below pectoral fin base; darker patches form broad jagged bands below dorsal fin origin, rear or dorsal fin base, below and in advance of adipose fin origin and in front of caudal fin base; row of six or seven moderately small pale spots just above lateral line; basal edge of pectoral fin with irregular narrow dark band. Snout, top of head and head behind and below eye rather uniformly dusky, operculum darker with distinctly pale branchiostegal membranes, strip along posterior edge of preopercle and rear half of upper jaw. Fins pale; recently preserved individuals with faint dusky angled stripes in dorsal fin and bands across lobes of caudal fin; distal half of adipose fin dusky.

Colour when fresh. Head and body olive brown to brown, ventral surface and prepectoral area white; back and sides crossed by four darker, broad jagged bands, intervening spaces blotched with white; bands centred on anterior part of dorsal fin, posterior end of dorsal fin base, adipose fin origin and based of tail; fifth band crossing back of head and covering operculum behind preopercle, preopercular edge, branchiostegals, most of maxilla and lower jaw white. Dorsal fin white with about four narrow reddish orange to somewhat brownish stripes angled slightly posteroventrally; distal margin narrowly white anteriorly, dark brown to black posteriorly. Anal fin white with obscure orange midlateral stripe. Caudal fin white with four or five narrow reddish orange bands crossing each lobe, basal band on lobes continuous across base of fin. Pectoral fin milky with four or five narrow reddish orange concentric bands. Pelvic fin reddish orange with white tips to anterior four rays ( Fig. 5C ).

Etymology. The specific name erythrozonatus is a combination of the Greek erythros for ‘red’ and zone for ‘belt’ in reference to the distinctive red bands on the dorsal and caudal fins. Again, we thank Thompson for suggesting the name.

Distribution. Apparently confined to the Australasian region with a trans-Tasman distribution, so far recorded from New Zealand’s Bay of Plenty on the northeastern coast of the North Island and off Batemans Bay in northern New South Wales ( Fig. 6 ), at depths of 130– 280 m. Shimizu and Yamakawa (1989) indicated the species also occurs on the Norfolk Ridge, but the specimen on which the authors based their information was not located until this contribution was in the final stages of publication. The specimen (NSMT-P 41872; G. Shinohara, pers. comm.) was unable to be examined to verify its identification.

Remarks. Both Shimizu and Yamakawa (1989) and Thompson and Stewart (2006) were aware of this species as evidenced by the figure prepared by the former, here reproduced as Fig. 5D , and the manuscript name made known to us by B. Thompson prior to his death. They distinguished the two by the numbers of dorsal fin rays (13 or 14 in L. damasi vs 16 in the new species), lateral line scales (33–37 vs 46) and vertebrae (37 vs 45). As is evident in the description above, the type series expands the variation in the values reported only very slightly. The two species are also separable by the relative lengths of the snout and eye, L. erythrozonatus having a smaller eye and longer snout, eye 1.6–1.9 in the snout (vs 1.2).

Figures

Fig. 1. TN93 neighbour-joining tree of 59 COI sequences from 4 purported genera and 11 purported species of Aulopidae, as well as sequences for an outgroup species, Paraulopus nigripinnis. Percent bootstrap values are given for all well supported nodes (>70%), followed by bootstrap values for these nodes in a TN93 maximum likelihood and a p-distance neighbour joining tree. See text. Specimen numbers are registration numbers of vouchers or those of the Barcode of Life Database (BOLD, www.barcodinglife.org) or GenBank (www.ncbi.nlm.nih. gov).

Fig. 2. Nasal flap: A) Hime pyrhistion sp. nov. NMNZ P.054047, holotype; B) Leptaulopus damasi NSMT-P. 115220, neotype; and, C) Leptaulopus erythrozonatus sp. nov. NMNZ P.042518, holotype.

Fig. 5. Species of Leptaulopus gen. nov.: A) L. damasi, NSMT-P115220, neotype, 297mm SL, Kagoshima Prefecture, Japan (photo by H. Motomura); B) L. damasi, CSIRO H 651–10, 170mm SL, Marion Reef, Queensland, Australia (photo courtesy of CSIRO); C) L. erythrozonatus sp. nov., NMNZ P.042518, holotype, 271mm SL, Bay of Plenty, New Zealand; and, D) new genus and species (after Shimizu and Yamakawa 1989), Norfolk Ridge, New Zealand.

Fig. 6. Collection localities for specimens examined of Letaulopus spp. Leptaulopus damasi (triangles): neotype black with blue centre and other material blue. Lepaulopus erythrozonatus sp. nov (squares): holotype black with red centre and paratype red.