Halicmetus westraliensis, Ho & Last, 2018

Ho, Hsuan-Ching & Last, Peter R., 2018, Review of the batfish genus Halicmetus Alcock, 1891 from Australian waters, with descriptions of two new species (Lophiiformes: Ogcocephalidae), Zootaxa 4508 (2), pp. 179-196 : 185-188

Halicmetus westraliensis sp. nov.

Vernacular name: West Australian Shortnose Seabat.

Figures 2B , 3 , 4 ; Tables 1–2

Holotype. CSIRO CA 3647 (68.4), SW of Imperieuse Reef, Rowley Shoals , Western Australia, 18°07’S, 118°09’E, 400–404 m, 5 Feb. 1983.

Paratypes. Sixteen specimens, 34.0– 85.8 mm SL. AMS I.22808-011 (1, 64.8), 220 km N of Port Hedland , Western Australia, 17°59’S, 118°17’ E, 404–420 m, 3 Apr. 1982 . AMS I.22821-026 (1, 64.6), 190 km NW of Port Hedland , Western Australia, 18°16’S, 118°12’E, 298–320 m, 10 Apr. 1982 . AMS I.22825-025 (1, 39.2), 200 km NW of Port Hedland , Western Australia, 18°59’S, 117°10’E, 300–326 m, 13 Apr. 1982 . AMS I.22826-021(1, 38.4), 210 km NW of Port Hedland , Western Australia, 18°44’S, 117°02’E, 396–406 m, 13 Apr. 1982 . CSIRO B 3121 (1, 64.4), SW of Rowley Shoals , Western Australia, 17°56’S, 118°21’E, 418–420 m, 5 Feb. 1983 . CSIRO B 3293 (5, 66.6–85.8), collected together with holotype . NMV A29670-019 (2, 34.0–47.5), North West Shelf , Western Australia, 18°34.2’S, 117°27.7’E, 401–405 m, 14 Jun. 2007 . NMV A29731 -028 (1, 64.0), North West Shelf , Western Australia, 12°31.8’S, 123°25.6’E, 401–404 m, 7–8 Jul. 2007 . WAM P.28080.005 (1, 62.5), Rowley Shoals , Western Australia, 16°50’S, 120°03’E, 433–434 m, 20 Aug. 1983 . WAM P.28341.002 (1, 55.5), Imperieuse Reef, Rowley Shoals , Western Australia, 17°58’S, 118°22’E, 406 m, 28 Feb. 1984 . WAM P.30586.004 (1, 93.4), North West Shelf , Western Australia, 19°20’S, 115°40’E, 348–352, 29 Jan. 1984 .

Non-types. AMS I.22822-018 (1, 39.2), 200 km NW of Port Hedland, North West Shelf , Western Australia, 18°23’S, 117°41’E, 396–418 m, 11 Apr. 1982 . NMV A29670-024 (1, 14.6), collected together with NMV A29670- 0 19 . NMV A29676-006 (1, 15.3), North West Shelf , Western Australia, 17°31’S, 118°51.2’E, 405–406 m, 16 Jun. 2007 . NMV A29731 -028 (1 of 2, 26.0), North West Shelf , Western Australia, 19°43.8’S, 115°21.2’E, 389–423 m, 12 Jun. 2007 . NTM S.14368-014 (1, 34.9), S of Cartier Reef , Timor Sea, 12°43.1’S, 123°33.2’E, 13 Jun. 1996, 280 m.

Diagnosis. A species of Halicmetus distinguished by the following combination of characters: disk moderately broad, 66–74% SL; orbit small, 7.2–8.9% SL; interorbit narrow, 6.3–8.3% SL; illicial trough opening low; middorsal disk covered with mixed simple and bifurcated spinules; tiny bucklers evenly distributed on dorsal surface, imperceptible without magnification; belly covered with closely spaced, simple spinules and slightly larger, scattered multicuspid tubercles; dorsal-fin rays usually present; pectoral-fin rays 11–12 (modally 12); dorsal surface pale pink, covered with a dense pattern of faint dusky blotches when fresh, uniformly creamy white when preserved; peritoneal membrane pale with sparse melanophores; distal parts of pectoral, pelvic and anal fins pale.

Description. Proportional measurements of type specimens, expressed as percentages of SL, and meristic data are given in Tables 1 & 2 respectively.

Dorsal-fin rays 0–3; anal-fin rays 4; pectoral-fin rays 12–13. Body depressed; disk subtriangular, margin rounded, broader than long, weakly truncated anteriorly; skull slightly elevated anteriorly when viewed in lateral profile; orbit small, directed dorsolaterally; rostrum bony, almost flat, plate-like, not overhanging mouth; illicial cavity situated entirely under rostrum, opening broad, much wider than high; nostrils located on each side of ventrolateral margins of illicial cavity; esca a fleshy bulb, usually with 2 short filaments on its dorsal margin.

Mouth small, horizontal, slightly curved dorsally; lower jaw projecting slightly; teeth villiform, small, in wide band in both jaws; quadrangular tooth patches on vomer and palatines. Fifth ceratobranchials bearing large and elongated tooth plates (tongue teeth, sensu Bradbury 1967, 1980), situated adjacent each other.

*denotes values of holotypes.

Gill filaments present, only on 2nd and 3rd gill arches; 3–4 gill rakers on 2nd gill arch; gill opening small, slitlike, beside dorsal, inner portion of pectoral elbow. Dermal cirri present, associated with lateral-line system on disk margin and tail. Pectoral fins well developed, extending from posterior margin of disk; pelvic fins centrally on ventral surface of disk, their origin slightly closer to mouth than to anus; dorsal fin usually present as a single short ray (often obscure), well forward of anal fin when present; anal fin short-based, situated on ventromedial surface near mid-length of tail.

Squamation on dorsal disk consisting of close-set spinules and numerous, very small bucklers (mostly imperceptible without magnification); spinules minute, mainly simple on central disk, becoming more frequently bifurcate on head and near disk margin; bucklers much smaller than 1 mm wide, elevated slightly above spinules, usually spiny; bucklers on frontal ridge relatively low and small, first 2 fused to form flat bony plate-like rostrum; supraorbital membrane (eyelid) covered with spinules. Ventral surface of disk predominantly covered with simple spinules; very small spiny bucklers dispersed loosely over surface. Disk margin with 3 obvious rows of large bucklers, less distinct along its posterior margin; uppermost bucklers in semi-regular row, low, broad based, lacking well defined spinelets; median and lowermost rows of bucklers taller, associated with lateral line, apices elevated and spiny, directed laterally, lowermost row inferior to median row, neuromasts well defined. Subopercular buckler enlarged, extended laterally beyond disk margin; with enlarged anterior spine (usually present and possibly damaged in some specimens), overlaid with smaller spinelets (variable in size and coverage). Pectoral-fin base covered dorsally with small but well developed spiny bucklers; bucklers in single row over anterior fin ray. Tail armoured, entirely covered in strong bucklers; dorsal surface with two parallel median rows and two irregular dorsolateral rows of large, low, long-based bucklers; rows coalescing posteriorly, eventually forming single, enlarged, keel-like buckler at caudal-fin base (surface comprised of smaller, somewhat obscure bucklers); lateral margin with two rows of bucklers associated with lateral line, similar in appearance to those of disc margin, their apices directed posterolaterally; ventral surface with 2 regular rows of low bucklers, coalescing to single, enlarged, keel-like buckler at caudal-fin base. Caudal-fin bucklers well developed, with variable coverage; bucklers thick, spiny, often persistent for about 3/4 of ray length; median rays usually with best developed bucklers.

Lateral line canal system well developed. Supraorbital series 4 or 5; body series 8 or 9; premaxillary series 1; cheek series 8; preopercular series 2; subopercular series 7; dorsolateral branch of subopercular series 3; ventral series 1; tail series 9–10.

Colour. Fresh specimens pale pinkish or yellowish brown on median disc and tail, suffused with fainter darker brown irregular blotches; margin of disk pale; all fins pale; ventral surface probably paler than dorsal surface. In preserved specimens, dorsal surface usually uniformly creamy white, occasionally with less distinct irregular marble patterns; all fins and ventral surface pale. Buccal cavity pale, pharynx gray. Peritoneum pale with scattered melanophores.

Distribution. Known from specimens collected from off the west coast of Australia, between 12°S and 20°S, the bathymetric range 389– 423 m.

Etymology. The name westraliensis is a reference to the type locality, Western Australia.

Figures

FIGURE 2. Front view of five Halicmetus species. A. H. marmoratus, CSIRO H 954-03, 57.8 mm SL. B. Halicmetus westraliensis sp. nov., CSIRO CA3647, holotype. C. H. drypus sp. nov., holotype. D. H. ruber, WAM P.31798-003, 65.9 mm SL. E. H. reticulatus, CSIRO H 4070-48, 74.7 mm. All preserved specimens, not to scale.

FIGURE 3. Specimen collection sides of Halicmetus marmoratus (blue circles), Halicmetus westraliensis sp. nov. (red triangles) and Halicmetus drypus sp. nov. (yellow square).

FIGURE 4. Halicmetus westraliensis sp. nov., CSIRO CA3647, holotype, 68.4 mm SL. A. fresh. B. preserved.