Galaxias longifundus, 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 : 74-79

Galaxias longifundus , new species

West Gippsland Galaxias

Tables 4 to 9, 12, 23 & 24; Figures 7 & 17

Galaxias olidus olidus (non G. olidus Günther, 1866 )— Frankenberg, 1969: 170 (partim).

Galaxias olidus (non G. olidus Günther, 1866 )— McDowall & Frankenberg, 1981: 469 (partim); Cadwallader & Backhouse, 1983: 69 (partim); Raadik et al. 2001: 78; McDowall, 2003a: 364 (partim).

Galaxias sp. 9 — DSE, 2013: 17; Raadik & Nicol, 2013: 1.

Galaxias sp. 13— Kuiter, 2013: 70.

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

Material Examined.

Holotype. NMV A.30575-2, 81.0 mm LCF, (71.2 mm SL), female, Rintoul Creek, east branch, at ford on C12 Track, north of Tyers , Victoria, 38° 02' 09”S 146° 28' 09”E, T.A. Raadik, 28 February 2002.

Paratypes. AMS I.44921-001 (2), 67.8–78.8 mm LCF (59.4–69.9 mm SL) and NMV A.30575-1, (8), 66.8–98.7 mm LCF (58.4–87.4 mm SL), collected with holotype.

Non-type material. VIC: NMV A.30590-1 (19), Rintoul Creek , at type locality 10 December 1998 ; NMV A.9861 (6) and NMV A.12675 (32), Jeeralong Creek , S of Traralgon, January 1918 .

Diagnosis. Galaxias longifundus sp. nov. differs from all other species within the Galaxias olidus complex by a combination of the following characters: long dorsal and anal fin bases (11.2–12.4 and 10.6–12.1 % SL, respectively); long dorsal and anal fins, with dorsal fin and base lengths longer than that of anal fin; eye relatively small (14.9–18.4 % HL); gape narrow (50.6–63.7 % HW); body depth through pectoral fin base only slightly greater (108.7 %) than depth through vent; nostrils moderately long, usually just visible anterio-laterally from ventral view; eyes well below dorsal head profile; most posterior extent of mouth usually 0.9 ED below ventral margin of eye; caudal peduncle flanges distinctive, long and also extend along outer rays onto caudal fin; caudal fin emarginate to almost truncate; usually 10 segmented anal fin rays and only 11 total gill rakers on first arch; gill rakers moderately long; often 1, sometimes 2, thin and pointed pyloric caecae of moderate length (2.2 % SL), very occasionally absent; anal fin origin usually under 0.58 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 11 specimens, 58.4–87.4 mm SL, and 6 additional, non-type specimens for meristics. See Tables 4 to 9 for frequencies of meristic values and Table 23 for a summary of meristic variation. Segmented dorsal fin rays 9 (9–11), of these 8 (7–8) branched and 2 (1–2) unbranched; segmented anal fin rays 10 (10–11*), of these 8 (8–9) branched and 2 (2–3*) unbranched; caudal fin rays 16 [14*]; segmented pectoral fin rays 14 (13–15), of these 12 (11–13) branched and 2 unbranched; pelvic fin rays 7, of these 6 branched and one unbranched; gill raker total count (lower limb and upper limb) 11 (11–12), lower arch with 9 (9–10) and 3 (3–4) on upper, variation on first gill arch 8+3 (8*), 9+2 (1), 9+3 (6), 9+4 (2); vertebrae 54 (52–54); two, more often one*, pyloric caecae on stomach, occasionally absent.

See Table 24 for comparative value ranges of morphometric characters. Body moderately deep and long, dorsal midline usually flattened anteriorly from above or slightly posterior to pectoral fin bases, depth through pectoral base 1.1 (1.0–1.2) that through vent, trunk with dorsal profile arched from snout to dorsal fin (ventral profile less so), upper surface of head straight to slightly arched, body tapering back to a relatively narrow (12.3 (11.4–13.5) in SL) caudal peduncle of moderate length, 7.5 (6.8–7.9) in SL), the peduncle depth 1.6 (1.5–1.9) in its length; accessory lateral line present. Head of moderate length, 4.6 (4.4–4.7) in SL, and usually slightly shorter (1.1 (0.9–1.2) than PelAn distance, of moderate depth and width (2.3–2.6 and 1.5–1.7 in HL respectively), distinctly wider than deep (depth 1.4–1.6 in HW), lateral profile wedge-shaped; eyes of moderate size, 5.9 (5.4–6.7) in HL, situated reasonably high on head though well below dorsal head profile, interorbital flat to slightly convex, moderately broad, 2.6 (2.4–2.9) in HL and 2.2 (1.9–2.8) times ED; cheeks expanded slightly below eyes, eye profiles visible laterally from ventral view in small to medium-sized individuals, obscured in larger, older specimens; snout moderately long, about 3.4 in HL and 1.8 (1.6–2.0) times ED, lateral profile bluntly rounded; post-orbital head length of moderate length, 1.8 (1.7–1.9) in HL; nostrils relatively long and just visible anterio- laterally from ventral view; mouth terminal, of moderate length, 2.7 (2.5–2.9) in HL, posterior extent reaching back to below anterior 0.1–0.5 of eyes and 0.9 (0.7–0.9) ED below ventral margin of eye, most anterior tip of upper lip level with about middle of eye, gape moderately narrow, 2.9 (2.4–3.2) in HL, width usually 0.9 of length of upper jaw and 1.8 (1.6–2.0) in HW. Jaws subequal, lower usually a little shorter (1.1 (1.0–1.2) in UJL). Pyloric caecae of moderate length, longest usually 2.2 % SL (0.8–4.8 %), thin and pointed to rounded; gill rakers moderately long, stout and pointed.

Fins fleshy at bases, paired fins less so, with thickening extending distally over 0.3–0.5 of fin area, extending farther between fin rays, dorsal and anal fin bases relatively long and usually equal in length or dorsal slightly longer, fins rounded and relatively long, dorsal a little longer than anal, middle rays longest; anal fin origin usually under 0.58 (0.45–0.73) distance posteriorly along dorsal fin base. Pelvic fins of moderate length, 8.6 (8.1–10.3) in SL, 0.9 of pectoral fin length, inserted at about mid-point of standard length and extending 0.5 distance to anal fin base; pectoral fin of moderate length and paddle-shaped, 7.7 (7.0–9.3) in SL, extending 0.4 distance to pelvic fin base, low on body with dorsal end of fin base level with posterior extent of mouth, lamina of paired fins oriented anterio-ventrally, raised lamellae usually present and strongly developed on ventral surface of rays. Caudal fin of moderate length, 7.3 (6.6–8.4) in SL, emarginate to almost truncate, similar in length to caudal peduncle, upper rays sometimes longer than lower, vertical width of expanded rays equal to or slightly greater than body depth through pectoral fin base, flanges distinctive, moderately low but strongly developed along caudal peduncle, long, reaching anteriorly past distal margin of adpressed anal fin, usually more than 0.6 distance to anal fin base, profile of ventral flange usually straight (sometimes slightly curved) across peduncle/caudal fin boundary, that of dorsal flange usually with a slight inflection, flanges extend posteriorly on caudal fin to near outer rays.

Size. Recorded to 97 mm LCF and 11 g; commonly to 65–80 mm LCF.

Colour in life. Body predominantly olive-brown on back and upper sides above lateral line, extending onto top and sides of head and snout, becoming light brown on lower lateral sides of trunk to cream ventrally. Overlain by small to moderate sized, relatively diffuse, dark brown to black, spots and blotches, some coalescing to form irregularly shaped bars; wide and usually faint mid-lateral band of gold flecks becoming iridescent posteriorly, and dorsal midline with thin row of gold or copper flecks extending from nape to dorsal fin origin. Some individuals occasionally with a few, small, slightly diffuse, black circles or ovoid bars on lateral. Gill cover translucent with small golden patch; iris golden; fins translucent olive-grey. See below for more detailed comments on body pattern.

Colour of preserved material. Base colour of head and body light brown to creamy tan. Small, round to elongate, pale and slightly diffuse brown spots to blotches on dorsal surface of trunk, extending down sides and slightly ventrally past lateral line; absent from ventro-lateral and ventral surface; greatest density on dorsal surface. A band consisting of a series of irregular shaped, small to large, dark grey blotches, sometimes 2–3 deep, along middle of sides, extending from just posterior to gill cover and onto caudal peduncle; blotches occasionally tending to very small, thin, elongate, vertical bars, some becoming quite dark brown, contrasting in tone to others. Distinctive dark grey, narrow, vertical lateral band located at posterior end of caudal peduncle, at the base of the caudal rays. Top and sides of head slightly grey-brown with fine black to brown-grey stippling. Some black fine spotting inside operculum and on base of gill filaments.

Eye black to grey, pupil translucent pale orange-yellow. Teeth translucent yellow to pale orange-yellow, tips orange to orange-red; gill rakers creamy to pale yellow. Fins generally pale creamy yellow to pale tan, becoming more translucent on posterior margins, fleshy bases of dorsal, anal, pelvic and pectoral fins cream to tan, usually with light grey, fine stippling. Base of caudal fin with a diffuse, pale grey, vertical blotch or bar.

Etymology. From the Latin longus, meaning long and fundus, meaning base, bottom, in reference to the relatively long dorsal and anal fin bases in this species compared with other members of the Galaxias olidus complex. Suggested vernacular name as the ‘West Gippsland Galaxias’.

Genetics. Allozyme and mtDNA analysis of this species can be found in Adams et al. (2014; taxon code RI). Diagnostic allozyme loci (6–17) between this taxon and the other species in the Galaxias olidus complex are provided in Table 12.

Distribution. See Fig. 7 . Currently only known from the headwaters of Rintoul Creek east branch, a tributary of the La Trobe River in Victoria, at an elevational range of 195–275 m asl. Known from a 4 km reach of stream (~ 0.75 m average width), commencing approximately 1.4 km (river distance) from the source, which is at 420 m asl, draining a catchment area of approximately 18 km 2. Downstream distribution unknown, though not recorded 2 km (river distance) farther downstream (March 2010), 18 km downstream in the main stem of Rintoul Creek (W4 Track) where the alien species Brown Trout was present (1998, 2002, 2006, 2010), or elsewhere in adjacent catchments (e.g. Tyers River, Eaglehawk Creek, Fells Creek). Comparison with museum specimens suggests that this species was historically more widely distributed in the lower La Trobe River catchment, being recorded from Jeeralang [sic] (= Jeeralong) Creek catchment in 1918, and possibly extending further upstream in the La Trobe River from Traralgon, before trout reduced their range.

Sympatry. Only species of the Galaxias olidus complex found within its restricted range, and in the La Trobe River system, though Galaxias gunaikurnai sp. nov. and Galaxias lanceolatus sp. nov. are known from the Macalister River system, which drains into the Thompson River system, a tributary of the La Trobe River. Also recorded with Galaxias brevipinnis .

Habitat. Recorded from a moderately shaded, gently flowing, small and shallow (2.0 m average width and 0.5 m average depth) creek, consisting predominantly of pools with smaller areas of shallow riffle (0.05 m average depth). Substrate consisted of boulder, cobble and pebble, with small amounts of gravel, sand and clay. Instream cover was provided predominantly by rock with smaller amounts of logs, branches and bank/vegetation overhang, and pools averaged 0.9 m (0.6–1.1 m) in depth.

General Biology. Confined to freshwater and considered not to undertake diadromous migrations. Recorded at a density of 0.27 fish/m 2 in 2002, and 0.004–0.01 fish/m 2 in 2012 ( Raadik & Nicol 2013). Collected with the native species Shortfinned Eel, Broadfinned Galaxias, Gippsland Spiny Crayfish , a species of burrowing crayfish ( Engaeus sp. ) and Common Freshwater Shrimp. Spawning period unknown, though probably during spring: about 50 % of fish collected in early December (1998) were between 28–38 mm LCF and considered of 0+ age, suggesting a late November hatching and possibly October spawning. Found to be infected by metacercarial cysts embedded in the skin or fins, and one individual recorded with a short, thin, white worm, coiled and pointed at both ends, from amongst fat deposits around stomach in the body cavity.

Conservation status. Critically endangered ( DSE 2013). Of concern is the dramatic decline in fish density to <0.01 fish/m 2 recorded in 2012, which is 1.7% of the densities recorded in 2002 ( Raadik & Nicol 2013). Whilst trout have historically reduced the abundance of this species, it appears that instream sedimentation following fire in the upper Rintoul Creek catchment may currently be responsible for this recent further decline in abundance ( Raadik & Nicol 2013). This demonstrates the high risk of extinction from stochastic events once a species has been reduced to a single, small population.

Remarks. One gravid female was collected from Jerralong Creek outside of the probable spawning period for this species (see above) in January 1918 (NMV A.12675), though this date is highly likely to be the date of accession into the museum collection rather than a collecting date. Additional efforts should be made to locate fish from Jeeralang Creek, or nearby in the rivers draining to the north from the Strezelecki Ranges, in order to confirm their identity as Galaxias longifundus .

A school of galaxiids was observed swimming near cover in a pool in the headwaters of the Tanjil River (east branch), behind the Mt. Baw Baw Ski Club in the Mount Baw Baw Alpine Village in February 1974 (T.A. Raadik, personal observation). Given the elevation of this location these fish are considered to belong to the Galaxias olidus complex and represent only the third recorded locality for this complex in the La Trobe River catchment. Unfortunately no specimens were retained, and additional sampling in 2002 and 2011 at the site, farther downstream, below the village, at ‘The Morass’ and elsewhere on the plateau, failed to relocate them, or to record any species of fish ( Raadik 2011, Raadik & Nicol 2013). Consequently the identity of this member of the Galaxias olidus complex remains unresolved and additional sampling on the Baw Baw Plateau, and elsewhere in headwater reaches of the La Trobe River catchment, is urgently required.

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 17. A–B: Galaxias longifundus sp. nov. holotype, NMV A.30575-2, 81.0 mm LCF, Rintoul Creek, C12 Track, north of Tyers, Victoria, A) line drawing (R. Plant), B) image of preserved specimen (note: tail curved slightly to the left in horizontal plane) (T.A. Raadik); C) G. longifundus sp. nov., female, 65 mm LCF, collected at the type locality, 30 April 2012 (T.A. Raadik); D) Rintoul Creek, at type locality of G. longifundus sp. nov., 30 April 2012 (T.A. Raadik). Scale bar = 5 mm.