Brachiopsilus ziebelli, 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 : 27-32

Brachiopsilus ziebelli sp. nov.

Figs 2 , 3 , 6 , 10, 13; Tables 2, 7–10

Brachionichthys sp. 1 : Edgar, Last & Wells, 1982: 38, fig. 23 [Ziebell’s morph].

Brachionichthys sp. 2 : Edgar, Last & Wells, 1982: 38, fig. 24 [Loney’s morph].

Brachionichthys sp. 1 : Last, Scott & Talbot, 1983: 251–252, fig. 22.3.

Sympterichthys sp. : Anonymous, 2005: 2.

Holotype. CSIRO T 1993–01 , 101.5 mm SL, Actaeon Islands, D'Entrecasteaux Channel , Tasmania, ca. 43° 32'S, 147° 00'E, 12 m, 22 Apr. 1980.

Paratypes. 10 specimens (42–117 mm SL): CSIRO H 4116–01 , 94.4 mm SL, Actaeon Islands, D'Entrecasteaux Channel, Tasmania, ca. 43° 32'S, 147° 00'E, 10 m, 1985; CSIRO H 6821–01 , 42.6 mm, off Forestier Peninsula , Tasmania, ca. 42° 58'S, 148° 00'E, 20 m, 18 Mar. 2003; CSIRO T 6 , 95.4 mm SL, Actaeon Islands , D'Entrecasteaux Channel , Tasmania, ca. 43° 32'S, 147° 00'E, 15 m, 1 Jul. 1983; CSIRO T 8, 116.8 mm SL, near Southport Island , D'Entrecasteaux Channel , Tasmania, ca. 43° 29'S, 147° 01'E, 15 m, 19 Jun. 1981; CSIRO T 1993–02 , two specimens, 86.3 and 104.8 mm SL, same data as holotype; CSIRO T 1994–01 , damaged, Actaeon Islands, D'Entrecasteaux Channel, Tasmania, ca. 43° 32'S, 147° 00'E, no other data; CSIRO T 1995–01 , 93.1 mm SL, Actaeon Islands , D'Entrecasteaux Channel , Tasmania, ca. 43° 32'S, 147° 00'E, 15 m, Apr. 1980; QVMT 2009.5. 3, 102.3 mm SL, Cox Bight , Tasmania, ca. 43° 31'S, 146° 13'E, no other data; TMH D 738 , 89.1 mm SL, Recherche Bay , D'Entrecasteaux Channel , Tasmania, ca. 43° 33'S, 146° 45'E, 12 m, 15 Nov. 1965 .

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

Additional material. 3 specimens (95–112 mm SL). CSIRO H 669–01 , 95.3 mm SL, north of Fortescue Bay, Tasman Peninsula , Tasmania, ca. 43° 05'S, 147° 58'E, 10 m, Oct. 1986 ; CSIRO H 4117–01 , 104.6 mm SL, off Cape Hauy, Tasman Peninsula , Tasmania, ca. 43° 09'S, 148° 01'E, 16 m, 21 Sep. 1985 ; CSIRO T 1996–01 , 112.0 mm SL, Waterfall Bay, Tasman Peninsula , Tasmania, ca. 43° 04'S, 147° 57'E, 10 m, May 1983 .

Diagnosis. Member of the genus Brachiopsilus with a combination of the following characters: esca small, 19–32% of illicium length; illicium thick, fleshy, length 18–24% SL, 2.4–3.0 times in head length, 1.2– 1.4 times in length of second dorsal-fin spine; apex of esca situated well posterior of hind margin of eye when illicium adpressed; esca slightly wider than illicial stem, covered with dense, short papillae; head bulbous; eye small (horizontal diameter 5–6% SL); mouth broad; lips very fleshy with vertical folds; body and fins entirely naked in adults (except for scales associated with pores of the acoustico-lateralis system); 4 sensory pores above eye; short first dorsal-fin base (length 21–25% SL); second dorsal-fin rays 16–18, length of fin base 63–70% SL; length of second dorsal-fin spine 0.8–1.2 times length of longest ray of second dorsal fin; 9–10 anal-fin rays, length of anal-fin base 34–38% SL; 9 pectoral-fin rays; short caudal peduncle (length 2–5% SL); caudal fin small, its length barely longer than fin rays of pectoral fin, length 2.7–3.4 times caudal peduncle depth; body whitish with fine, greyish purple peppering; fins vivid yellow.

Description. D1 2 (2, n= 10 paratypes); D2 17 (16–18, n=9); A 9 (9–10, n=9); Pc 9 (9, n=10); Pv i, 4 (i, 4, n=8); C 1 (1) + 6 (5–6) + 2 (2–3) = 9 (9, n=9); Vt 10 (9–11, mainly 10) + 13 (13–14) = 23 (22–25, mainly 23, n=9).

Body moderately short, robust anteriorly, bulbous, suboval in cross section (paratype CSIRO T 8 laterally flattened due to preservation); upper anterior profile strongly convex, not truncate before second dorsal fin; upper margin of eye well below dorsal margin of head, just above level of illicial base; head subcircular when viewed anteriorly; nape humped prominently; anterior ventral profile weakly convex; abdomen sometimes expanded slightly; caudal peduncle short, length 4 (2–5)% SL. Head length 57 (51–57)% SL; snout short, 6.6 (6.1–6.7) times in head; eye very small, lateral, somewhat embedded, 11.5 (8.6–12.3) times in head length; gill opening small, aperture subequal to pupil, located posterodorsal to and well away from insertion of pectoral fin. Nostrils relatively small, openings obvious; anterior opening close to mouth; posterior opening small, almost posterodorsal to anterior opening, very well separated from orbit, situated slightly below level of mid eye. Mouth broad, terminal, slightly protrusible; upper jaw short, oblique to subhorizontal, 4.4 (3.5– 4.7) in head; lips appearing fleshy, covered with dense arrangement of deep, longitudinal folds; angle of jaw not deeply recessed into groove, situated below anterior half of eye; tongue narrowly rounded apically. Teeth dense, villiform, similar in shape and size in both jaws; in bands, broad, irregular anteriorly (5–7 teeth wide, but not in rows), becoming narrower posteriorly, extending almost to angle of jaw; vomer edentate.

Skin thick, very flabby, uniformly naked (apart from sensory pores) on body and fins; no scales or spinules embedded in skin of adults; skin lacking wart-like patches, instead usually heavily wrinkled, some specimens heavily bloated with smooth skin (probably from osmotic effects during preservation); no obvious dermal flap present on mid-arm of pectoral-fin; dermal flaps absent from body. Illicium covered with thick, wrinkled or papillose skin; skin forming a broad, pouch-like covering, much broader near its base. Acousticolateralis system variably developed; scales bicuspid; spinules barely detectable without staining, spine apices overlain with broad, lobe-like integument (often elevated well above surrounding skin); sensory scales variably separated, more evenly spaced on tail; sensory canals obvious to indistinct, demarcated by surface lines and papillae; canals usually arranged in very obvious series on head, particularly around mouth and on forehead, usually less obvious on tail; 4 sensory pores above eye; sometimes as well-defined line extending from above eye horizontally to gill opening, descending abruptly then continuing along middle of tail to basal caudal rays.

Illicium long, terminal on snout, vaguely asparagus-shaped, 3.0 (2.4–2.9) times in head, 1.2 (1.2–1.4) times in length of second dorsal-fin spine; apex of esca well posterior of base of third dorsal-fin spine when fin depressed; partly retractable into distinct groove on either side of first dorsal fin; esca small, narrow, densely covered with small papillae, 3.9 (3.1–4.3 in adults; 5.4 in juvenile paratype, CSIRO H 6821–01) times in length of illicium, emanating from a slightly narrower, tubular stem; illicial base slightly bulbous. First dorsal fin well developed, base moderate, not connected to second dorsal fin; spines thickened, second dorsalfin spine almost confluent with base of illicium, much longer than third spine; fin membrane greatly thickened, fleshy, not expanded over spine bases; membrane variably extended onto nape, terminating slightly posterior to apex of erect third dorsal-fin spine; anterior elements of both fins weakly recurved; first dorsal-fin base 2.7 (2.6–3.3) times in second dorsal-fin base. Second dorsal fin elevated, incised slightly, anterior and penultimate posterior rays longest; rays usually simple (4 th and 7 th last rays of holotype branched to their midpoints); fin base elongate, 64 (63–70)% SL; longest ray of second dorsal fin 1.0 (0.8–1.2) times in longest dorsal-fin spine; basal membrane relatively thick, sometimes concealing bases of fin rays. Anal-fin margin weakly incised, rays elongate, penultimate posterior rays longest; anal-fin base fleshy, 1.9 (1.7–1.9) times in second dorsal-fin base. Pectoral fin elongate, enlarged, prominently arm-like, elbow extending well beyond gill opening; fin rays broadly digitiform, membranes deeply and uniformly incised, tips flexible, broadly triangular. Pelvic fin well developed; rays broad, weakly incised; anterior spine short, distinct; all rays embedded in thick skin; fin located on ventral surface, directed laterally, base aligned horizontally; interpelvic space broad, almost flat. Caudal fin small, margin narrowly rounded; barely larger than rayed portion of pectoral fin, length 2.9 (2.7–3.4) times caudal peduncle depth.

Coloration. In life: Body pale with variable covering of greyish pink flecks on back, along upper tail, and on head behind eyes; fins brilliant yellow, coverage variable, usually over most of dorsal, caudal, pectoral and pelvic fins, usually present on anal fin, sometimes extending beyond fin bases onto body.

In preservative: Yellowish markings lost and dark markings less distinct, body often almost uniformly white.

Size. Attains at least 116.8 mm SL (ca. 151 mm TL); smallest specimen examined 42.6 mm SL. Paratype CSIRO T 1993–02 (104.8 mm SL) is gravid, capsule diameter of ca. 1.9 mm. Newly hatched young unknown.

Distribution. Restricted to eastern and southern Tasmania in widely disjunct populations; in the southern parts of the D’Entrecasteaux Channel (ca. 43° 30'S, 147° 03'E), Cox Bight, south-west Tasmania (ca. 43° 31'S, 146° 13'E), and the Forestier and Tasman Peninsulas (ca. 43° S, 148° E). Also photographed by scuba divers in situ off Bicheno, eastern Tasmania. Demersal in about 10–20 m depth.

Etymology. Named in honour of Alan Ziebell, a professional diver, who hand collected some of the first specimens near the Actaeon Islands (D’Entrecasteaux Channel) when fishing for abalone. These specimens were initially displayed in a marine aquarium at his home and later donated to us for research. Proposed vernacular name: Ziebell’s Handfish.

Comparisons. Differs from other large handfish occurring off southern Tasmania, Brachiopsilus dianthus , in coloration and morphometrics, and is slightly different in meristics. Brachiopsilus ziebelli has a shorter first dorsal-fin base (length 21–25 vs. 26–30% SL in B. dianthus ), second dorsal-fin base (length 63– 70 vs. 73–76% SL), anal-fin base (length 34–38 vs. 38–39% SL), a smaller eye (horizontal diameter 4.6–6.0 vs. 5.8–7.1% SL), and shorter first dorsal-fin spines (second spine 22–31 vs. 32–36% SL; third spine 16–22 vs. 24–30% SL). However, the illicium (length 18–24 vs. 15–16% SL) and caudal peduncle (length 2.3–5.3 vs. 0.8–2.1% SL) are both longer in B. ziebelli . These differences are reflected in the following non-standard ratios: head length 2.4–3.0 vs. 3.0–3.5 times illicium length; second dorsal-fin spine 1.2–1.4 vs. 2.0–2.3 times illicium length; longest dorsal-fin spine 0.8–1.2 vs. 1.3–1.5 times longest ray of second dorsal fin; second dorsal-fin base 1.7–1.9 vs. 1.9–2.0 times anal-fin base length; head length 8.6–12 vs. 7.7–8.8 times eye diameter; and illicium length 34–43 vs. 28–34% of head length. Brachiopsilus ziebelli is primarily whitish (purplish in Loney’s form) with yellowish fins whereas the only fresh specimen of B. dianthus was almost uniformly pink. Both species are high count forms with similar second dorsal and anal-fin counts but differ slightly in pectoral-fin ray counts (9, n=22 including both fins of each specimen vs. 9–10, mean 9.6, n= 8 in B. dianthus ) and caudal vertebral counts (13–14, mean 13.3, n=10 vs. 12–13, mean 12.8, n=4).

Brachiopsilus ziebelli differs from B. dossenus mainly in body shape and morphometrics. Available specimens of B. ziebelli are typically much larger (86–112 mm SL) than the B. dossenus types (52–65 mm SL). However, a small paratype of B. ziebelli (CSIRO H 6821–01, 43 mm SL) closely resembles the adult in body shape being much more elongate with a dorsal profile that is not strongly humped as in B. dossenus . The two species differ in several body proportions that do not appear to be size related: snout to anal-fin origin (61–63 vs. 55–59% SL in B. dossenus ), head length (51–57 vs. 48–50% SL), interorbital width (6.9–8.8 vs. 8.6–10% SL), illicium length (18–24 vs. 13–16% SL), caudal-fin length (29–38 vs. 37–44% SL); caudal peduncle length (2.3–5.3 vs. 1.5–1.7% SL) and depth (9.8–12 vs. 8.4–9.9% SL), total length (129–139 vs. 137–144% SL), first dorsal-fin base (length 21–25 vs. 29–30% SL), second dorsal-fin base (length 63–70 vs. 77–79% SL), anal-fin base (length 34–38 vs. 40–44% SL), eye (horizontal diameter 4.6–6.0 vs. 7.1–8.6% SL), length of second dorsal-fin spine (22–31 vs. about 34% SL), and length of third dorsal-fin spine (16–22 vs. 24–29% SL); and non-standard ratios including head length 8.6–12 vs. 5.8–6.7 times eye length and 2.4– 3.0 vs. 3.1–3.6 times illicium length, second dorsal-fin spine 1.2–1.4 vs. 2.1–2.3 times illicium length, caudalfin length 2.7–3.4 vs. 4.1–5.2 times caudal peduncle depth, and illicium length 34–43 vs. 28–32% head length.

Remarks. In 1980, the first photographs of this species alive were taken in situ in the Derwent Estuary (figured in Edgar et al., 1982, p. 39 as Brachionichthys sp. 1 ) of a relocated specimen collected earlier by abalone diver, Alan Ziebell, near the Actaeon Islands (D’Entrecasteaux Channel, Tasmania). This specimen, having a pale body, purplish patches dorsally, and striking, yellow-edged fins, typifies the Ziebell’s colour morph. In 1981, a local underwater photographer, Ian Loney, captured an image of a large, densely mottled, purplish handfish at Waterfall Bay (Tasman Peninsula) at about 10 m depth – this form has been subsequently referred to as Loney’s Handfish (figured in Edgar et al., 1982, p. 39 as Brachionichthys sp. 2 ). Occasional specimens of this colour morph have been taken and/or observed by divers in recent decades at the Tasman Peninsula. These forms, which are similar morphologically, differ mainly in colour but there are subtle variations within and between forms. Collection material of the typical Ziebell’s morph tend to have flabby skin (firmer in preserved specimens of Loney’s morph) and the dark body and yellow fin markings are no longer evident (i.e. now uniformly white whereas the purplish coloration is retained by the Loney’s morph) – these differences may be artefacts of preservation. Similarly, some type specimens of B. ziebelli kept for several weeks in aquaria before fixation had apparently metabolized some axial musculature before death biasing their morphometrics. A compressed body was rarely evident in undamaged specimens (e.g. CSIRO T 8).

These forms have been regarded as separate species ( Edgar et al., 1982) or variants ( Last et al., 1983) but given their morphological similarity and the presence of specimens off Tasman Peninsula with a colour pattern intermediate between the forms (i.e. a mottled purplish body with yellowish fin tips), this needs to be substantiated. In the past two years, as part of a larger project to investigate conservation issues in handfishes, CSIRO biologist, Mark Green, has searched without luck for additional material of both forms to obtain tissues for molecular analysis. Given these uncertainties, Loney’s morph has been provisionally assigned to B. ziebelli pending further investigation. As such, specimens of Loney’s morph were omitted from the type series.

Only one juvenile specimen of B. ziebelli (CSIRO H 6821–01) is known. It was collected by a scuba diver off Tasman Peninsula (southeastern Tasmania) after it had been sequentially ingested and regurgitated by two Butterfly Perch ( Caesioperca lepidoptera ). This handfish was initially mottled purplish grey on the body and the margins of at least the dorsal fins were yellowish (M. Baron, pers. comm.). It also resembles adult B. ziebelli in general morphology and most counts but, unlike them, it has long dermal filaments over its body and fins and a light scattering of minute, embedded, unicuspid and bicuspid spinules that are visible only under high magnification and good lighting. Spinules are densest on the head. Also, the skin is very thin and partly sloughed off, presumably through damage from its encounter with the Butterfly Perch.

The regurgitation of the young handfish by two serranids is interesting as these fish might produce toxins to deter predators. One of the paratypes (CSIRO T 1994–01), while being held in a small bucket of seawater awaiting transfer to an aquarium, was caught by the householder’s cat and most of its tail (about 5 grams) eaten. The cat, which reportedly became sleepy, coughed, vomited and then suffered paralysis of its hind legs, finally suffered respiratory failure and died within 1.5 hours. There are observations in the literature that suggest frogfishes ( Antennariidae ) may be toxic but these have been guardedly rejected by Pietsch & Grobecker (1987). We know of no other confirmed reports of toxicity of the flesh of lophiiform fishes.

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.