Chaunax reticulatus, Ho, Hsuan-Ching, Roberts, Clive D. & Stewart, Andrew L., 2013

Ho, Hsuan-Ching, Roberts, Clive D. & Stewart, Andrew L., 2013, A review of the anglerfish genus Chaunax (Lophiiformes: Chaunacidae) from New Zealand and adjacent waters, with descriptions of four new species, Zootaxa 3620 (1), pp. 89-111 : 102-105

Chaunax reticulatus sp. nov.

New English name: Netted frogmouth ( Figures 10 A–C, Table 2 )

Holotype: NMNZ P. 040686, 188 mm, northern Three Kings Ridge, New Zealand, 28º35.7'S, 172º55.65'E, F/V Clarabelle, stn. OBS 1735/022, 360–398 m, bottom trawl, 21 Jan. 2003, coll. Simon Beatson.

Paratypes: 11 specimens, 30–102 mm SL. New Zealand: NMNZ P.033934, 78 mm, SE of Alderman Islands, New Zealand, 36º55.975'S, 176º16.81'E, 3 F/V Drysdale, stn. DRY 9602/001, 95 m, bottom trawl, 18 Oct 1996. New Caledonia: MNHN 2002–0172, 3, 74– 102 mm, Norfolk Ridge, 23°37' 59"S, 167°43'1"E, Campagne Chalcal 2, stn. CP 25, 418 m, beam trawl, 30 Oct. 1986. MNHN 2003–1094, 64 mm, Norfolk Ridge, 23°37'01''S, 167°40'59''E, Campagne Lithist, stn. CP 2, 442 m, beam trawl, 10 Aug. 1999. MNHN 2003–1124, 3, 30–58 mm, Norfolk Ridge, 23°37'05''S, 167°42'00''E, Campagne Lithist, stn. CC6, 440– 579 m, otter trawl, 10 Aug. 1999. MNHN 2003–1521, 76 mm, Norfolk Ridge, 23°42'05''S, 168°15'00''E, Campagne Lithist, stn. CP 14, 378 m, beam trawl, 12 Aug. 1999. MNHN 2003–1532, 73 mm, Norfolk Ridge, 23°43'01''S, 168°16'01''E, Campagne Lithist, stn. CP 16, 379 m, beam trawl, 12 Aug. 1999. NMNZ P.029330, 98 mm, Jumeaux Seamount, S of New Caledonia, 23º48.75'S, 168º17.1'E, Beryx 11, stn. 53, 540– 950 m, beam trawl, 21 Oct. 1992, coll. C. Roberts & C. Paulin.

Diagnosis. A member of the Chaunax fimbriatus -species group with cirri on head, reticulate colour pattern on dorsal surface and more than 3 pairs of spinules in lateral-line neuromast complex. Distinguished from congeners in having greyish dorsal background colour with pale reticulate pattern; cirri present above the eye and absent from lower part of maxilla; 4–6 pairs of stout spinules bridging each neuromast; 14 pectoral-fin rays; relatively long and slender illicium; elongate illicial trough, longer than wide; and numerous thin brownish cirri on esca. Gill rakers: GRi = 12–13 (3+8–9); GRii = 9; GRiii = 9; GRiv = 7–8. Lateral-line neuromasts: AB = 11–12 (modally 11); AC = 7–9 (8); BB' = 4–5 (4); BD = 2–3 (2); CD = 5–8 (6–7); EF = 3–4 (4); FG = 3–4 (3); GH = 11–13 (12); BI = 30–35.

Description. Morphometric and meristic data are given in Table 2 . Head length 2.4 (2.3–2.4) in SL; head width 5.1 (4.9–5.2) in SL, 2.1 (2.1–2.2) in HL; pre-dorsal length 2.0 (1.9–2.0) in SL; pre-gill opening length 1.5 (1.5–1.6); pre-preopercular length 3.7 (3.3–3.7) in SL, 1.5 (1.4–1.5) in HL; upper jaw 4.7 (4.3–4.8) in SL, 2.0 (1.8–2.0) in HL; illicial length 11.6 (9.3–12.0) in HL; illicial trough length 6.0 (4.4–6.7) in HL; eye diameter 6.0 (4.4–6.0) in HL; post-dorsal fin length 5.1 (5.1–6.9) in SL, 2.1 (2.1–3.0) in HL; post-anus length 3.5 (3.2–4.0) in SL, 1.4 (1.4–1.8) in HL; post-anal fin length 6.9 (6.3–6.9) in SL, 2.9 (2.7–3.3) in HL; caudal peduncle depth 4.2 (4.2–4.6) in HL; caudal fin length 3.3 (2.9–3.3) in SL, 1.4 (1.3–1.4) in HL.

Head globular, skull slightly elevated posteriorly; trunk cylindrical, slightly compressed, tapering posteriorly; ventral surface flattened; skin thick, loose and flaccid; interorbital space broad; caudal peduncle short, slightly compressed, tapering posterior. Eyes rounded, directed dorsolaterally, covered by dermal membrane broadly connected to adjoining skin, forming clear “window”.

Illicium long and slender; esca with small central tongue bearing many thin brown cirri; second dorsal-fin spine close to illicium, embedded under skin; third dorsal-fin spine situated at about mid-point of pre-dorsal distance, embedded under skin. Illicial trough slender, slightly concave, its length about twice its width.

Two nostrils anterior to eye, anterior nostril surrounded by fleshy membrane, posterior part higher than anterior part, posterior nostril a simple round hole; mouth wide, terminal, its opening nearly vertical; lower jaw slightly protruding in front of upper jaw; maxilla tapering above, broad below; blunt symphyseal spine on lower jaw symphysis.

Broad transparent membrane on first gill arch; first ceratobranchial well connected to opercular wall; gill filaments present on second to fourth gill arches, two rows of gill filaments in second and third gill arches, single row of gill filaments on fourth gill arch; those on inner row of third arch and fourth gill arch about two–third length of other arches; inner surface of fourth gill arch completely connected to body. Single row of 11–12 rakers on 1stgill arch, 3 on upper limb and 8–9 on lower limb, 9 paired rakers on 2nd arch, 9 paired rakers on 3rd arch andsingle row of 7–8 rakers on 4th arch.

Interspaces of lateral-line neuromast complex slightly wider than its width; 4–6 pairs of short spines bridging each neuromast.

Skin thick, that covering pectoral and pelvic fins forming thick membrane, tips of rays not free. Dermal spinules short and stout, covering entire body except for eye window, outer half of pectoral fins, entire anal fin and membranes of all fins. Wide band of 8–10 rows of dermal spinules in front of illicial trough.

Teeth in both jaws slender, fang-like; 8 irregular rows (5–6 rows in two paratypes) in upper jaw, teeth gradually increasing from outer to inner row, inner row longest, more than twice length of those in outer row; lower jaw with 5–6 irregular rows of teeth and in similar arrangement. Teeth on vomer small, in about 3 rows, forming two wide bands, well–separated by a small space; those on palatine small, forming an elongated patch and close to outer end of vomer teeth.

Dorsal-fin rays III, 12; first shortest, about half length of second; all simple except last two branched. Pectoral fin fan-shaped, with 14 rays, 4th or 5th longest, gradually shorter from the 6th to behind. Anal fin with 6–7 rays, first shortest, first and second simple, third to last branched. Caudal fin truncate, with 9 rays, second to seventh branched, remaining 3 simple, lower most ray shortest, close to adjacent one.

Colouration. Fresh: unknown. Preserved: (juveniles, paratypes) white reticulate pattern on light grey background; (adult, holotype) reticulate pattern stronger, transforming into many small irregular pale grey spots. Esca with deep brown cirri in all sizes.

Distribution. Known only from type series collected from seamounts and oceanic ridges of northern New Zealand and southern New Caledonia, at depths of 360–950 m ( Fig. 8 ).

Etymology. From the Latin “retis” – net, means netted or reticulate, in reference to the netted colour pattern of the body.

Remarks. To date, Chaunax reticulatus is the only member of the C. fimbriatus – species group known from the southern Pacific Ocean. This group currently comprises four nominal species: C. fimbriatus from the northwestern Pacific Ocean, C. umbrinus Gilbert, 1905 from Hawaii, C. flammeus Le Danois, 1979 from the western Indian Ocean, and C. reticulatus described herein.

Chaunax reticulatus can be distinguished from others in the group by the pale reticulate pattern on a grey background dorsally. It further differs from C. fimbriatus in lacking two white patches on the dorsal surface (vs. two large white patches present), from C. umbrinus in its pale reticulate pattern being relatively thick and welconnected (vs. finely marbled), and from C. flammeus in having a distinct pattern (vs. unpatterned, based on the sole holotype).

Cirri on the head are sometimes hard to detect due to preservation. With careful examination, a few were found above the eyes of the holotype but none were found on the lower part of the maxilla.

The holotype is a mature female with two large, empty ovaries. It appears to have just spawned suggesting the breeding season may be during summer months.

An apparently aberrant specimen collected from East Cape, North Island, New Zealand (NMNZ P.037208) may be close to C. reticulatus . It differs from the type series of the present species in having a relatively short and narrow head, a relatively long tail, and a relatively low caudal peduncle. It may be a specimen of an undescribed species, but more specimens are needed to assess its status.

Figures

FIGURE 8. Distribution map of three Chaunax species in present study. Circle = Chaunax penicillatus. Triangle = C. reticulatu sp. nov. Square = C. russatus sp. nov. Open symbols are primary types. A symbol may represent more than one capture. Dashed line = limit of Exclusive Economic Zone. Prepared by C. Struthers, Te Papa. Dashed line = limit of Exclusive Economic Zone. Prepared by C. Struthers, Te Papa.

FIGURE 10. Chaunax reticulatus sp. nov. A. Holotype, NMNZ P. 040686, 188 mm SL, dorsal view. Photo C. Struthers, Te Papa. B. Drawing of lateral view of holotype, illustrated by M. Freeborn, Te Papa. C. Laterodorsal view of paratype, MNHN 2003 – 1532, 73 mm SL, photo: H. – C. Ho, NMMB, Taiwan.

Tables

TABLE 2. Morphometric and meristic data for three Chaunax species in present study. Meristic features are counted on both sides when paired. H = holotype. SD = standard deviation. * donates value of holotype.

C. reticulatus sp. nov.			C. russatus sp. nov.	C. penicillatus
H Types		H	Types	Non–types
SL (mm) 188 64–188 (n=7)		170	100–214 (n=22)	97–197 (n=9)
Morphometric value (% SL) Mean (Range)	SD		Mean (Range) SD	Mean (Range) SD