Brachiopsilus dianthus, Last & Gledhill Csiro, 2009

Last, Peter R. & Gledhill Csiro, Daniel C., 2009, A revision of the Australian handfishes (Lophiiformes: Brachionichthyidae), with descriptions of three new genera and nine new species 2252, Zootaxa 2252 (1), pp. 1-77 : 21-25

Brachiopsilus dianthus sp. nov.

Figs 2 , 3 , 6 , 10, 11; Tables 1, 7–10

Holotype. CSIRO H 4995–01 , 99.5 mm SL, Tasman Peninsula , Tasmania, ca. 43° 13'S, 147° 57'E, 38 m, Feb. 1999.

Paratypes. 3 specimens (69–90 mm SL): CSIRO A 1901 , 68.5 mm SL, mouth of Huon River, D'Entrecasteaux Channel , Tasmania, ca. 43° 20'S, 147° 08'E, 4 Feb. 1958; TMH D 123 , 2 specimens, 79.7 and 90.4 mm SL, off Dennes Point, D'Entrecasteaux Channel , Tasmania, 43° 03'S, 147° 21'E, 1 Apr. 1947 .

Diagnosis. Member of the genus Brachiopsilus with a combination of the following characters: esca of medium size, 29–38% of illicium length; illicium smooth, thin, not exceedingly fleshy, length 15–16% SL, 3– 3.5 times in head length, 2.0–2.3 times in length of second dorsal-fin spine; with illicium adpressed, apex of esca situated above posterior half of eye; esca much wider than illicial stem, covered with dense, short, filaments; head slightly compressed; moderate-sized eye (horizontal diameter 6–7% SL); mouth narrow; lips fleshy with irregular folds; body and fins entirely naked in adults (except for scales associated with pores of the acoustico-lateralis system); 5 sensory pores above eye; long first dorsal-fin base (length 26–30% SL); second dorsal-fin rays 17–18, fin base 73–76% SL; length of second dorsal-fin spine 1.3–1.5 times length of longest ray of second dorsal fin; 9–10 anal-fin rays, length of anal-fin base 38–39% SL; 9–10 pectoral-fin rays; very short caudal peduncle (length 1–2% SL); caudal fin of medium size, its length much longer than fin rays of pectoral fin, length 3.2–4.0 times caudal peduncle depth; body pinkish red, darker reddish brown markings along dorsal fin margins remnant in preservative.

Description. D1 2 (2, n= 3 paratypes); D2 18 (17–18); A 10 (9–10); Pc 9 (9–10); Pv i, 4 (i, 4); C 1 (1) + 6 (6–7) + 2 (2) = 9 (9–10); Vt 11 (10–11) + 13 (12–13) = 24 (22–24).

Body moderately elongate, slightly compressed anteriorly (more so in paratypes), not bulbous; upper anterior profile strongly convex, well elevated before second dorsal fin; upper margin of eye well below dorsal margin of head, well above level of illicial base; head oval when viewed anteriorly; nape humped prominently; anterior ventral profile weakly convex, much less so than dorsal profile; abdomen little expanded; caudal peduncle short, length 2 (1–2)% SL. Head length 47 (51–55)% SL; snout short, length 6.1 (5.7–7.3) times in head; eye of moderate size, lateral, somewhat embedded, diameter 8.1 (7.7–8.8) times in head length; gill opening small, aperture slightly larger than pupil, located adjacent and directly posterior of insertion of pectoral fin. Nostrils enlarged to greatly enlarged, openings usually obvious; anterior opening close to upper jaw; posterior opening expanded, posterodorsal to anterior opening, relatively well separated from orbit, its upper edge above mid orbit. Mouth narrow, terminal, moderately protrusible; upper jaw weakly oblique, 4.3 (4.0–4.3) in head; lips fleshy, densely covered with papillose longitudinal folds; angle of jaw deeply recessed into groove (less so on smallest paratype), positioned below anterior half of eye; jaws connected by a membrane about a third of their length from angle; tongue broadly rounded apically. Teeth dense, villiform, in subcrescentic bands, similar in shape and size in both jaws; bands narrow anteriorly (3–5 teeth wide in smallest paratype, but not in defined rows), becoming narrower posteriorly (terminating in a single row), extending barely half way to angle of jaw; vomer edentate.

*Distance from the base of the third dorsal-fin spine to the origin of the second dorsal fin.

FIGURE 10. Collection localities for: A. Brachiopsilus dianthus sp. nov., holotype () and paratypes (•); B. B. dossenus sp. nov., holotype () and paratypes (); C. B. ziebelli sp. nov., holotype (), paratypes and other typical specimens (); and D. B. ziebelli sp. nov., Loney’s morph (). Locations are approximate, and may represent multiple records.

Skin thick, highly mobile, uniformly naked on body and fins; no embedded scales or spinules evident in skin (apart from scales associated with sensory pores); skin lacking wart-like patches in holotype (smallest paratype with patches of indistinct warts on tail), instead smooth or heavily wrinkled, no specimens bloated; no obvious dermal flap present on mid-arm of pectoral-fin; dermal flaps absent from body. Illicium with covering of thick, smooth skin; skin not papillose, forming a narrow, pouch-like cover around supporting ray, almost uniform in width along length of illicium. Acoustico-lateralis system well developed; scales bicuspid; spinules elevated, evident without staining, spine apices overlain with subtriangular integument; sensory scales variably separated, more evenly spaced on tail, 5 above eye; sensory canals indistinct; canals demarcated by scales on head, prominent around mouth, side of head, forehead, and on tail; lateral line extending from above eye horizontally along middle of tail to basal caudal-fin rays.

Illicium moderately elongate, terminal on snout, not asparagus-shaped, 3.0 (3.5) times in head, 2.0 (2.2– 2.3) times in length of second dorsal-fin spine; apex of esca extending to base of third dorsal-fin spine when fin depressed; partly retractable into distinct groove on either side of first dorsal fin; esca enlarged slightly to bulbous, densely covered with small filaments, 3.1 (2.6–3.4) times in length of illicium, emanating from a much narrower stem; illicial base enlarged slightly in holotype (less so in paratypes). First dorsal fin well developed, tall, base elongate; spines thickened slightly, second dorsal-fin spine almost confluent with base of illicium, much longer than third spine; fin membrane thickened slightly, not expanded over basal rays; membrane usually connected to second dorsal fin by low membranous ridge; anterior rays of both fins weakly recurved; first dorsal-fin base 2.9 (2.5–2.6) times in second dorsal-fin base. Second dorsal fin well elevated, not incised; rays simple; fin base very elongate, 75 (73–76) % SL; longest ray 1.3 (1.3–1.5) times in longest dorsal-fin spine; basal membrane not thickened, partly concealing bases of fin rays. Anal-fin margin weakly incised, rays elongate, penultimate posterior rays longest; anal-fin base fleshy, 1.9 (1.9–2.0) times in second dorsal-fin base. Pectoral fin elongate, enlarged, prominently arm-like, elbow extending well beyond gill opening; arm of holotype broadly connected to side of body by skin restricting extension anteriorly; fin rays weakly digitiform, membranes weakly incised, tips short, flexible, narrowly triangular. Pelvic fin moderately well developed; rays narrow, moderately incised; anterior spine short, indistinct; all rays embedded in thick skin; fin located on ventral surface, directed posterolaterally, base aligned horizontally; interpelvic space variable, narrow in holotype (broader in most paratypes), almost flat. Caudal fin moderate in size, its length much longer than fin rays of pectoral fin; length 3.5 (3.2–4.0) times caudal peduncle depth; margin broadly rounded.

Coloration. In life (based on the holotype and only specimen for which the coloration has been observed): body with reddish and pink blotches dorsally and on head; pink on chin and belly; dorsal fins similar to upper body coloration, fin margins reddish brown; rayed portion of pectoral fin, and caudal and anal fins paler with reddish brown marks on fin membranes; pelvic fin and illicium pinkish; eyes bluish black.

In preservative: Plain whitish, yellowish greenish or pink; dark streaks evident along margins of dorsal fins and on membranes of caudal and pectoral fins in holotype; dark markings on dorsal and caudal fins persistent in all paratypes.

Size. Attains at least 99.5 mm SL (ca. 136 mm TL); smallest specimen examined 68.5 mm SL. Size at maturity, newly hatched young and egg capsule diameter unknown.

Distribution. Demersal, recorded from southeastern Tasmania, from the Tasman Peninsula and the northern and central waters of the D'Entrecasteaux Channel. Bathymetric data only recorded for the holotype, collected at 38 m depth.

Etymology. Epithet based on the New Latin dianthus (carnation, pink) in allusion to its striking body coloration. Proposed vernacular name: Pink Handfish.

Comparisons. This species is compared with the two other new Brachiopsilus species in the following treatments of those species.

Remarks. This is a surprisingly poorly known species that occurs within scuba diving limits. Possibly a conservation concern as few specimens have either been caught or observed despite considerable activity by commercial, recreational and scientific interests across its defined geographic range. Any specimens observed should, if possible, be photographed in situ and the sighting reported to a local research agency.

Figures

FIGURE 2. Illustrations of the illicium and esca of: A. Brachionichthys australis, CSIRO H 4114–07, 55.8 mm SL; B. Brachionichthys hirsutus, CSIRO T 7, 78.9 mm SL; C. Brachiopsilus dianthus sp. nov., CSIRO H 4995–01, holotype, 99.5 mm SL; D. Brachiopsilus dossenus sp. nov., NMV A 29405–002, holotype, 65.0 mm SL; E. Brachiopsilus ziebelli sp. nov., CSIRO T 1993–01, holotype, 101.5 mm SL; F. Pezichthys amplispinus sp. nov., CSIRO H 4460–01, 37.2 mm SL; G. Pezichthys compressus sp. nov., CSIRO H 4447–01, holotype, 42.4 mm SL; H. Pezichthys eltanini sp. nov., LACM 11516–1, holotype, 30.0 mm SL; I. Pezichthys macropinnis sp. nov., CSIRO H 5317–02, holotype, 20.5 mm SL; J. Pezichthys nigrocilium sp. nov., CSIRO H 6154–01, holotype, 40.8 mm SL; K. Sympterichthys moultoni sp. nov., CSIRO H 3773–03, holotype, 45.1 mm SL; L. Thymichthys politus, CSIRO H 782–01, 67.3 mm SL; M. Thymichthys verrucosus (tasselled morph), CSIRO T 5, 51.3 mm SL; and N. Thymichthys verrucosus (eastern form) CSIRO H 3781– 01, 63.5 mm SL.

FIGURE 3. Skin morphology of: A. Brachionichthys australis, CSIRO H 4451–02 (x40); B. Brachionichthys hirsutus, TMH D 640 (x40); C. Brachiopsilus dianthus sp. nov., CSIRO H 4995–01, holotype (x20); D. Brachiopsilus dossenus sp. nov., NMV 29405–002, holotype (x20); E. Brachiopsilus ziebelli sp. nov., CSIRO T 1993–01, holotype (x25); F. Pezichthys amplispinus sp. nov., CSIRO H 4448–01, holotype (x50). All images orientated as a view of mid-upper body on left side (i.e. anterior part to left).

FIGURE 6. Underwater images of live handfishes (photographer K. Gowlett-Holmes): A. Brachiopsilus ziebelli sp. nov. (Loney’s morph) with egg mass, Waterfall Bay, Tasmania, not retained; B. Brachionichthys hirsutus, Derwent Estuary, Tasmania, not retained; C. Thymichthys politus, Primrose Bay, Tasmania, not retained; D. Thymichthys verrucosus (tasselled morph), habitat artificial, Tasmania; E. Brachiopsilus dianthus sp. nov., CSIRO 4995–01, holotype, 99.5 mm SL, habitat artificial, Tasmania; F. Sympterichthys moultoni sp. nov., CSIRO H 4461–01, paratype, 39.3 mm SL, habitat artificial, Tasmania.