Alabes bathys, Hutchins, 2006

Hutchins, Barry, 2006, Description of two new species of shore-eels (Gobiesocidae: Cheilobranchinae: Alabes) from south-eastern Australia and Norfolk Island, Memoirs of Museum Victoria 63 (1), pp. 25-28 : 26-27

Alabes bathys sp. nov.

Figures 1a, b ; Table 1

Material examined. Holotype. NMV A14558 , 39 mm SL, Tas., 30 km NNW of Cape Sorell (42°10.9'S, 144°48.9'E), WHOI epibenthic sled at 160 m, RS Wilson on board RV Soela (field no. S05/84 54), 20 Oct 1984.

Paratypes. NMV A28045-001 , 29 mm SL, taken with holotype (disarticulated cleared and stained skeletal material); CSIRO H.6156- 01, 38 mm SL, Tas., King I. Canyons, west of King I. (between 39°48'S, 143°08'E and 39°50'S, 143°07'E), Sherman sled at 348 m, FRV Southern Surveyor (field no. SS0404/35), 18 Apr 2004 .

Diagnosis. Alabes bathys differs from all other species of Alabes by a combination of its moderately large gill opening (width 3.1–3.7 in HL), somewhat smaller pelvic fin rudiment (width 1.4–1.6 in gill opening) consisting of 2 apparent fin rays in each half, 4 cephalic pores (1 POP, 1 ANP, 2 LP) in the lateral line system, and its unique colour pattern.

Description. Measurements of the holotype and paratypes are presented in Table 1 (counts and proportions in parentheses in the following description represent those of the paratypes where different from the holotype). Body elongate, subcylindrical, widest anteriorly (maximum body width at level of gill slit 21.7 [17.1–21.1] in SL), reaching a maximum depth about middle of body (depth 13.0 [12.6–13.1] in SL), tapering posteriorly; head small, cylindrical, length 7.5 (7.4– 8.6) in SL, slightly wider than body, width 2.1 (1.8–1.9) in HL; snout short, round to slightly truncate in dorsal view, length 4.0 (3.1–4.6) in HL; nostrils small but obvious, anterior 1 tubular, posterior 1 with low raised rim; eye moderate in size, with prominent clear cornea, diameter of orbit 3.3 (2.9–3.3) in HL, bony interorbital rather narrow, width 7.4 (7.3–7.8) in HL.

Skin smooth and scaleless, usually covered with mucus layer; lateral line sensory system consists of small open pores and minute papillae (latter very difficult to detect); 4 pores on each side of head, consisting of 1 POP and 1 ANP, and 2 LP. Gill opening a moderately wide slit, located on ventral surface of head, length 3.7 (3.1–3.5) in HL; gills 3?; branchiostegals 3; mouth terminal, gape not reaching vertical line through anterior margin of eye(pigmented area),lips narrow,somewhat fleshy; teeth in cleared and stained paratype small, conical, canine-like, 1 row of 6–8 teeth on each side of upper and lower jaws, largest anteriorly (premaxilla also with 3 much smaller teeth forming a 2nd row along inner base of main row); palatine and vomerine teeth absent. Dorsal and anal-fin folds resemble low fins, but lack both fin rays and underlying pterygiophores; caudal fin with 8 (7–8) fin rays, continuous with dorsal and anal-fin folds; bases of dorsal and anal-fin folds relatively long, insertion of dorsal-fin fold over or slightly behind vertical through urogenital opening, insertion of anal-fin fold well behind vertical through urogenital opening (snout to insertion of dorsal-fin fold 2.7 [2.6–3.2], snout to insertion of anal fin fold 2.0 [1.7–2.6], snout to urogenital opening 2.8 [2.7–2.8], all in SL); urogenital opening with prominent papilla. Total vertebrae not known for holotype but cleared and stained paratype has a total of 68 vertebrae, not including hypural plate (21 precaudal), with last epineural on 24th vertebra.

Colour in alcohol. Head and body overall pale brown, fins more translucent.

Colour in life. (Based on colour transparency of holotype, see fig. 1a): head and body pale brown, abdominal region more pinkish ventrally; body becoming more translucent posteriorly, vertical fins almost totally transparent; middle of side with longitudinal series of whitish spots from head almost to caudal fin, each spot about equal or subequal to eye diameter; dorsal surface with longitudinal series of similarly coloured short cross-bands, continued onto dorsal-fin fold as vertical bars; a few pale spots on anal-fin fold. Larger paratype differs in its ground colour, being a more pale greyish green (fig. 1b).

Distribution. Alabes bathys is known only from western Tas., in the region of Cape Sorrell and King I..

Remarks. This species has so far only been collected by dredge from deep coastal waters at depths between 160 and 348 m. It shares with Alabes dorsalis a large ventral gill slit and prominent ventral fin rudiment, but differs in the relatively narrow width of the latter fin (maximum width 1.4–1.6 versus 0.8–1.0 for A. dorsalis , all in length of gill slit). It also has a narrower body (maximum depth 12.6–13.1 verus 9.3–11.6 in SL), lacks the dark circular markings along the body and its small size (maximum length 42 mm TL versus 120 mm TL in A. dorsalis ).

Etymology. This species is named bathys (from the Greek “bathys ” meaning deep) with reference to its deep water habitat.

Figures

Figure 1a. Alabes bathys, holotype, NMV A 14558, 39 mm SL, off Cape Sorell, Tas. (photograph courtesy of Rudie Kuiter, NMV).