Ebinania australiae, Keith L Jackson, 2006

Keith L Jackson, 2006, Ebinania australiae, a New Species of Fathead Sculpin from Southern Australia (Scorpaeniformes: Psychrolutidae), Records of the Australian Museum 58, pp. 37-42 : 38-41

Ebinania australiae n.sp.

Figs 1–2, Tables 1–2

Type material. HOLOTYPE, CSIRO T 412, 206 mm Standard Length (SL), off Cape Sorell , Tasmania, 42°16'S 144°40'E to 42°22'S 144°42'E, 991– 548 m, 14 July 1982 . PARATYPES: CSIRO T 502, 218 mm SL, off Beachport , South Australia, 37°54'S 139°40'E to 37°50'S 139°36'E, 1000– 1000 m, 3 April 1983 ; CSIRO T 504, 296 mm SL, data same as T 502; CSIRO T 505, 266 mm SL, data same as T 502; CSIRO

T 506, 406 mm SL, data same as T 502 ; CSIRO T 536, 285 mm SL, off Cape Martin , South Australia, 37°51'S 139°40'E to 37°48'S 139°33'E, 1007– 960 m, 25 April 1983 ; NMV A 1977, 112 mm SL, off Cape Naturaliste , Western Australia, 33°17.9'S 114°12.6'E to 33°15.8'S 114°11.1'E, 982 m, 14 February 1991 ; NMV A 2741, 358 mm SL, off Cape Bridgewater , Victoria, Australia, 38°36'S 140°59'E to 38°38'S 141°07'E, 1040–1170 m, 27 June 1982 ; NMV A 2758, 284 mm SL, off Cape Bridgewater , Victoria, Australia, 38°38'S 141°04'E to 38°35'S 140°56'E, 990–1100 m, 27 June 1982 .

Diagnosis. A species of Ebinania with cirri on the head, well-developed thin and flexible orbital rims, cranial (frontal) arch 3 high and twisted upwards, prevomerine teeth in a continuous band, a single terminal chin pore, obsolete lateral line pores, and an overall pale colour.

Description. Ratios and counts are given in Tables 1 and 2. Body tadpole shaped. Head large, trunk short and tapering to a small tail. Head depressed at orbits and sloping dorsally to a moderately depressed nape. Trunk round, tapering to a moderately compressed peduncle. Orbits forward, snout blunt and wide. Interorbit wide and soft. Mouth large, terminal, and oblique. Jaws equal or upper jaw slightly protruding. Premaxilla and dentary with a band of villiform teeth in 5–6 (premaxilla) and 4–5 (dentary) irregular rows; prevomer with villiform teeth in a contiguous band of 2–3 irregular rows. Skin thin, gelatinous, very loose, and smooth (lacking prickles). Cirri small, simple or multiheaded, and present around the jaw and less frequently on the snout and head where magnification may be required to detect them. Anterior nostril raised on a tube, posterior nostril flush or only slightly raised on a tube. Terminal chin pore fused and minute. Lateral line pores obsolete.

All fins covered with loose skin. Dorsal fin without a deep notch between spinous and soft rayed parts. Dorsal fin spines barely discernible externally, with only minute nibs at the top of the embedded flabby fin. Lower pectoral fin with notches between ray tips. Caudal fin truncate.

Colour in alcohol very pale amber-brown. Irregular largescale mottling apparent, though differences between darkest and lightest areas slight; pectoral fins darkest. Peritoneum brown with dark flecks.

Frontals laterally expanded into a thin orbital rim. Frontal with four large arches. All arches, particularly arch 3, are strongly bilaterally asymmetric. Arch 3 high and twisted upwards. Arch 5 (anteriormost lateral extrascapular) borne upon and fused with pterotic. Arch 6 (medialmost transverse extrascapular) free from parietal. Five infraorbitals, first three well developed and articulated to form a suborbital bar, third with a stay extending to preopercle, last two simple and free tubular bones. Extrascapulars and posterior tubular infraorbitals each with a delicate or incomplete arch.

Variation. Nine specimens of Ebinania australiae , four of E. brephocephala , and two of E. vermiculata were examined. Morphometric and meristic data were also noted from Nelson (1982) and Quéro (2001). Variation of counts for all species of Ebinania is shown in Table 1. No single meristic trait or combination of meristic traits separates any of the species of Ebinania . However, when more specimens are available, pectoral fin ray counts may prove useful in separating species of this genus as they have been with the genus Neophrynichthys (Jackson & Nelson, 2000). Pectoral fin ray counts vary from 19 to 24 amongst the species of Ebinania ( Table 1). Specimens of E. vermiculata span the entire range of the genus in pectoral counts: the two specimens of E. vermiculata examined here had 21 and 24 rays, Sakamoto (1932) counted 22 pectoral rays on the holotype, and Watanabe (1960) counted 19 to 21 rays amongst 12 specimens of E. vermiculata . It is possible that Watanabe’s (1960) counts may be low because the upper rays of the pectoral fin are very closely spaced and must be counted after dissection of the skin at the pectoral base. Morphometric variation is great ( Table 2), probably because of the easily distortable nature of these fishes’ bodies. The morphometrics of the nine specimens of Ebinania australiae overlap with those of the other species of Ebinania , and no morphometric character is useful for the diagnosis.

Two traits used in the diagnosis of Ebinania australiae were observed to vary within some species: condition of the terminal chin pore and arrangement of the prevomerine teeth. All specimens of E. australiae examined had the terminal chin pore fused and medial, as opposed to paired. Although chin pore state has not been reported to vary within the other species of Ebinania , it varied in the specimens of E. brephocephala we examined (fused in HUMZ 74774, paired in HUMZ 74784, and indeterminable in the two cleared and stained specimens). The state of this pore is used herein (in conjunction with colour) to separate E. australiae from E. vermiculata ; however, this may not be reliable if it is found to vary in either of these two species as it does in E. brephocephala . All specimens of E. australiae examined had prevomerine teeth in a continuous band, as opposed to in two blocks separated by a distinct gap. Although the prevomerine teeth state has not been reported to vary within the other species of Ebinania , variation was observed in the two specimens of E. vermiculata , with teeth in two distinct blocks in HUMZ 34249 and teeth in a continuous band with only a slight medial constriction in HUMZ 78141. The condition of the prevomerine teeth is used herein to separate E. australiae from E. brephocephala and E. costaecanariae ; other characters separate these two species should prevomerine teeth be found to vary.

Ebinania australiae is distinguished from E. brephocephala and E. costaecanariae in having cirri on the head and prevomerine teeth in a continuous band as opposed to two patches separated by a distinct gap at the symphysis. It is distinguished from E. macquariensis in having well-developed orbital rims and cranial arch 3 high and twisted upwards as opposed to low and flat. It is distinguished from E. malacocephala in having obsolete lateral line pores rather than pores raised in tubules and prevomerine teeth in a continuous band. It is distinguished from E. vermiculata in having a single terminal chin pore and an overall light grey brown body colour as opposed to a medium brown blotchy colour.

Distribution. Ebinania australiae is known from southern Australia off the tip of Western Australia (one specimen), off southern South Australia and Victoria (7 specimens), and off Tasmania (one specimen) at 982–1170 m ( Fig. 3). The geographically closest congeneric species of Ebinania australiae is E. macquariensis from Macquarie Island, 1500 km southeast of Tasmania, and the next closest species is E. malacocephala from the far southern middle Pacific (54°49.5'S 129°47'W) (both described by Nelson, 1982).Two species, E. brephocephala and E. vermiculata , are known from the Northwest Pacific off Japan. The sixth species of Ebinania , E. costaecanariae is known from the eastern Atlantic off Spain ( Quéro, 2001) and Africa ( Nelson, 1982).

Etymology. The specific name australiae refers to the known occurrence of this species. Given the paucity of outwardly apparent specific characteristics within this genus, geographic names seem fitting for newly described allopatric species of this wide ranging genus. Gender feminine.