Galaxias lanceolatus, Raadik, 2014

Raadik, Tarmo A., 2014, Fifteen from one: a revision of the Galaxias olidus Günther, 1866 complex (Teleostei, Galaxiidae) in south-eastern Australia recognises three previously described taxa and describes 12 new species, Zootaxa 3898 (1), pp. 1-198 : 68-73

Galaxias lanceolatus , new species

Tapered Galaxias

Tables 4 to 9, 12, 21 to 22; Figures 7 & 16

Galaxias olidus (non G. olidus Günther, 1866 )— Raadik et al., 2001: 73.

Galaxias sp. 8 — DSE, 2013: 17; Raadik & Nicol, 2013: 1.

Galaxias sp. 15— Kuiter, 2013: 74.

Conforms to the allozymically defined and morphologically diagnosed taxon ‘ST’ of Adams et al. (2014), and ‘stoney’ of Raadik (2011).

Material Examined.

Holotype. NMV A.30552-3, 74.5 mm LCF, (66.5 mm SL), female, Stoney Creek, at ford on Stoney No. 5 Track, west of Seaton , Victoria, 37° 54' 10”S 146° 32' 32”E, T.A. Raadik, 27 February 2002.

Paratypes. AMS I.44916-001 (2), 68.7–74.8 mm LCF (60.6–65.8 mm SL) and NMV A.30552-2 (12), 67.1–76.9 mm LCF (59.4–67.9 mm SL), collected with holotype.

Non-type material. VIC: NMV A.30552-1 (6), 43.0– 68.1 mm LCF (42.1–60.5 mm SL), collected with holotype.

Additional non-type material examined (not measured): see Appendix 5.

Diagnosis. Galaxias lanceolatus sp. nov. differs from all other species within the Galaxias olidus complex by a combination of the following characters: trunk with dorsal and ventral profiles evenly arched from snout to dorsal fin; dorsal and anal fin lengths, and fin base lengths, about equal; snout and upper lip slightly anteriorly expanded and fleshy; dorsal midline usually broadly flattened anteriorly; dorsal profile of head distinctly flat anterior to nape; mouth cleft moderately oblique; nostrils short, not visible from ventral view; caudal peduncle flanges high and long, usually extending to near anal fin base, and also extending along outer rays onto caudal fin; caudal fin length usually just shorter than caudal peduncle length; pyloric caecae usually absent; anal fin origin usually under 0.66 distance posteriorly along dorsal fin base; and, lack of black bars along lateral line.

Description. As for the genus and members of the Galaxias olidus complex, except as indicated below, based on 15 specimens, 59.4–67.9 mm SL, and six additional, non-type specimens for meristics. See Tables 4 to 9 for frequencies of meristic values and Table 21 for a summary of meristic variation. Segmented dorsal fin rays 10 (10–11*), of these 8 (8–9*) branched and 2 (1–3) unbranched; segmented anal fin rays 11 (10–12*), of these 9 (8–10*) branched and 2 (1–2) unbranched; caudal fin rays 16; segmented pectoral fin rays 15 (14–16), of these 13 (12–14) branched and 2 unbranched; pelvic fin rays 7, of these 6 branched and one unbranched; gill raker total count (lower limb and upper limb) 13 (12–15; [14*]), lower arch with 9 (9–11; [10*]) and 3 (3–4*) on upper, variation on first gill arch 9+3 (6), 9+4 (3), 10+3 (4), 10+4 (4*), 11+3 (1), 11+4 (2); vertebrae 54 (53–55*); pyloric caecae usually absent.

See Table 22 for comparative value ranges of morphometric characters. Body moderately slender and elongate, dorsal midline usually broadly flattened anteriorly from above pelvic fin bases, depth through pectoral base 1.1 (1.0–1.2) depth that through vent, trunk with dorsal and ventral profiles evenly arched from snout to dorsal fin, slightly depressed on head; body tapering back to a caudal peduncle of moderate length, 7.5 (7.0–8.0) in SL, and depth, 13.0 (11.9–13.9) in SL, the peduncle depth 1.7 (1.6–1.8) in its length; accessory lateral line present. Head of moderate length, 4.7 (4.5–4.8) in SL and usually shorter (0.9) than PelAn distance, of moderate depth, 2.5 (2.4–2.8) in HL, and width (1.6 in HL), and distinctly wider than deep (depth 1.6 in HW), depressed dorsally and lateral profile wedge-shaped, dorsal profile distinctly flat anterior to nape; eyes of moderate size, 5.3 (5.0– 5.5 in HL; 2.1 (1.8–2.3) in HD), situated high on head, just below dorsal head profile, interorbital flat, of moderate width, 2.6 (2.4–2.8) in HL and 2.0 (1.8–2.1) times ED; cheeks slightly expanded below eyes, eye profiles just visible laterally from ventral view; snout moderately long, 3.4 (3.2–3.6) in HL and 1.5 (1.4–1.6) times ED, lateral profile dorsally slightly bulbous and anteriorly rounded to bluntly pointed as upper lip anteriorly expanded and fleshy; post-orbital head length of moderate length (1.8 in HL); nostrils relatively short, just extending to posterior edge of upper lip or less, not visible from ventral view; mouth generally terminal, of moderate length, 2.8 (2.6–3.0) in HL, posterior extent reaching back to under anterior 0.3–0.5 of eyes, and about 0.6 (0.5–0.7) ED below ventral margin of eye, cleft moderately oblique, most anterior tip of upper lip about level with middle of eye, gape of moderate width, 2.7 (2.6–2.8) in HL, width slightly longer than length of upper jaw and 1.7 (1.6–1.8) in HW. Jaws subequal, lower about 0.9 length of upper. Gill rakers short to moderate length, stout, bluntly rounded to sharply pointed.

Size. Recorded to 84 mm LCF and 6 g; commonly to 65–70 mm LCF.

Colour in life. Body predominantly brown to grey-brown on back and upper sides above lateral line, extending onto top and sides of head and snout, becoming brown to tan on lower lateral sides of trunk to light brown or cream ventrally. Overlain by diffuse, pale brown, dark brown or almost black blotches, or elongate and narrow vertical to chevron bars, extending down sides to lower lateral surface; some individuals occasionally with one or two, small, slightly diffuse, black circles or ovoid bars on lateral midline. Faint mid-lateral band of gold flecks visible posteriorly, and dorsal midline sometimes with a thin row of gold flecks extending from nape to dorsal fin origin. Gill cover translucent with small golden patch; iris copper; fins translucent grey. See below for more detailed comments on body pattern.

Colour of preserved material. Base colour of head and body pale cream to creamy yellow. Dorsal surface of head (including snout) and trunk overall tan to light brown, darkest mid dorsally, fading rapidly dorso-laterally, and then gradually down the sides, extending ventrally past lateral line almost to ventral surface as sparse, fine stippling. Sides with a distinctive series of diffuse, pale brown to grey, elongate and narrow, closely to moderately space, vertical to chevron bars, centred on the lateral line and extending dorsally and ventrally, extending from above and slightly posterior to pectoral fin base posteriorly to caudal peduncle; occasionally, smaller, diffuse blotches located above lateral line, though much fainter, otherwise sides free of patterning. Nape, interorbital, snout and upper lip grey-brown, extending onto cheeks and opercles as fine brown stippling. Some brown spotting inside operculum and dark brown to very spots on base of gill filaments.

Eye black to dark grey, pupil translucent pale orange yellow. Teeth translucent yellow to pale, tips pale orange–yellow; gill rakers pale creamy yellow. Fins generally pale cream, becoming more translucent on posterior margins, caudal with slight dusky hue. Fleshy bases of dorsal, anal, pelvic and pectoral fins cream.

Etymology. From the Latin lanceolatus , meaning lance-like, in reference to the comparatively elongate body shape of this species with relatively evenly arched dorsal and ventral profiles, except when close to spawning. Suggested vernacular name as the ‘Tapered Galaxias’.

Genetics. Allozyme and mtDNA analysis of this species can be found in Adams et al. (2014; taxon code ST). Diagnostic allozyme loci (6–14) between this taxon and the other species in the Galaxias olidus complex are provided in Table 12.

Distribution. See Fig. 7 . Only known from the headwater reaches of Stoney Creek, a tributary of the Thomson River in west Gippsland, Victoria, at an elevational range of 340–545 m asl. Confined to a 10 km reach of stream (~ 0.75 m average width) commencing about 1.5 km (river distance) downstream from the source, which is at 690 m asl, draining a catchment area of approximately 26 km 2. Downstream distribution unknown, though not recorded a farther 8 km (river distance) downstream where the alien species Brown Trout were present, or elsewhere in adjacent catchments (e.g. Glenmaggie Creek) ( Raadik & Nicol 2013).

Sympatry. Only species in the Galaxias olidus complex found within its restricted range. Found in the same river basin as Galaxias gunaikurnai sp. nov., which is geographically isolated in the upper reaches of a headwater tributary of the Macalister River, approximately 70 km farther north-east.

Habitat. Recorded from a cool, small (0.5–1.5 m), shallow (0.1–0.5 m), clear and slow-flowing, partly shaded freshwater creek in a forested catchment. Substrate consisted predominantly of cobbles, with some gravel, bedrock and sand, and instream cover was provided mostly by rock, and by small amounts of undercut banks, timber debris and vegetation overhang.

General Biology. Confined to freshwater and considered not to undertake diadromous migrations. Recorded at densities of 0.01–0.9 fish/m 2 and collected with the native species Broadfinned Galaxias, Shortfinned Eel , Central Highlands Spiny Crayfish, Gippsland Spiny Crayfish and Common Freshwater Shrimp. Spawning period unknown, though possibly late winter to spring: the majority of fish collected in early May were at a mature stage of gonad development (gonads filling nearly entire body cavity) with some males running ripe ( Raadik & Nicol 2013), the smallest presumed 0+ age fish recorded in early November 1998 was 23 mm LCF (9 fish in length range 23–26 mm LCF), and the smallest fish collected in late February 2002 was 43.0 mm LCF (NMV A.30552-1). One individual recorded with a short, thin, white worm (nematode?), coiled and pointed at both ends, from amongst fat deposits around the stomach in the body cavity.

Conservation status. Critically endangered ( DSE 2013).

Remarks. One individual, cited as Galaxias olidus (s.l.), was recorded from nearby in Glenmaggie Creek in January 1988 ( Hall 1989). The specimen was not retained, and assuming that its identification at the time was correct (to the olidus group given Galaxias brevipinnis is abundant further upstream), the specific identity of the presumed population in this system requires clarification. Therefore, systematic survey effort, focussing on headwater sections of smaller streams in the Thomson River catchment, is required to determine if additional, remnant populations remain and to accurately delineate the small distribution of Galaxias lanceolatus . Considered to have been historically more widespread, throughout the entire Stoney Creek system and within portions of the Thomson River, including the Deep Creek system, and may have ranged into the lower Macalister River system.

Figures

FIGURE 7. Distribution of Galaxias aequipinnis (open circles), Galaxias brevissimus (grey square), Galaxias gunaikurnai (black square), Galaxias lanceolatus (grey circle), Galaxias longifundus (black diamond), Galaxias mcdowalli (inverted black triangle), Galaxias mungadhan (open squares), Galaxias supremus (open triangle), Galaxias tantangara (grey triangle), and Galaxias terenasus (black circles) (river basins shown—refer to Fig. 1).

FIGURE 16. A–B: Galaxias lanceolatus sp. nov. holotype, NMV A.30552-3, 74.5 mm LCF, female, Stoney Creek, Stoney No. 5 Track, west of Seaton, Victoria, A) line drawing (R. Plant), B) image of preserved specimen (T.A. Raadik); C) G. lanceolatus sp. nov. female, collected at the type locality, ~ 75 mm LCF, 1 May 2012. (T.A. Raadik); D) Stoney Creek, at type locality of G. lanceolatus sp. nov., 1 May 2012 (T.A. Raadik). Scale bar = 5 mm.