Galaxias fuscus Mack, 1936

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 : 53-62

Galaxias fuscus Mack, 1936

Barred Galaxias

Tables 4 to 9, 12, 17 to 18; Figures 11 , 13 to 14

Galaxias fuscus Mack, 1936: 100 (holotype: NMV A.96; paratype (1) NMV A.99; type locality: Rubicon River, Victoria) [see Appendix 1 for text of original description];— Whitley, 1956b: 39; 1956c: 34, fig. 1; Munro, 1957: 17; Whitley, 1957a: 7; Whitley, 1964: 35; Lake, 1971: 20; Dixon, 1972: 121; McDowall & Frankenberg, 1981: 472; Cadwallader & Backhouse, 1983: 64, plate p. 190; Ealey et al., 1983: 44 (partim); Merrick & Schmida, 1984: 85 (partim); Schmida, 1985; 149; Rich, 1986: 21 (partim); Leggett & Merrick, 1987: 93 (image); Allen, 1988: 3; Allen, 1989; 37, plate 55; Shirley, 1991; Armstrong, 1993; Wager & Jackson, 1993; Raadik, 1995a; Raadik et al., 1996: 108; Raadik, 1999; Shirley & Raadik, 1997; Raadik, 2000; Raadik, 2001: second image from bottom p. 787; Raadik, 2002; Allen et al., 2003: 99; Kuiter, 2003: 976 and images; Raadik, 2006a; Raadik, 2006b: 138; Lintermans, 2007: 40; Davies et al., 2008: 338; Schmida, 2008: image on contents page; Raadik et al., 2010; Ayres et al., 2012a; 2012b: 1; Stoessel et al., 2012: 1; DSE, 2013: 17; Kuiter, 2013: 46; Lieschke et al., 2013a,b; Raadik & Nicol, 2013: 1.

Galaxias ornatus (non G. ornatus Castelnau, 1873 )— Butcher, 1946: 9 (partim).

Galaxias olidus fuscus ( Mack, 1936) — Frankenberg, 1969: 171; Terzis, 1986: 1.

Galaxias olidus (non G. olidus Günther, 1866 )— McDowall, 1980: 57 (partim); McDowall & Frankenberg, 1981: 469 (partim); Rich, 1986: 21 (partim); McDowall & Fulton, 1996: 55 (partim); McDowall, 2003b: 364 (partim).

Galaxias olidus var. fuscus — Koehn & Raadik, 1995: 1.

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

Material Examined.

Holotype. NMV A.96, 74.9 mm LCF, (65.3 mm SL) [dried out], Rubicon River , Victoria, (?) 37° 19' 37”S 145° 51' 39”E, A.C. Payne, 1935.

Paratype. NMV A.99 (1), 83.1 mm LCF (73.5 mm SL) [dried out], collected with holotype.

Non-type material. VIC: NMV A.30247-1 (2), 70.6–74.7 mm LCF (61.8–64.7 mm SL), Criss Cross Creek, off Criss Cross Road, Toolangi State Forest , 37° 27' 39”S 145° 28' 13”E, TAR, 10 September 1998 ; NMV A.30243-1 (1), 85.2 mm LCF (75.0 mm SL), Criss Cross Creek , same location as NMV A.30247-1, TAR, 18 June 2002 ; NMV A.30267-1 (4), 94.2–114.6 mm LCF (82.8–100.1 mm SL), Falls Creek, Bindaree Road, below Bindaree Falls , Mt. Stirling, 37° 09' 04”S 146° 33' 12”E, TAR, 15 May 2001 ; NMV A.30249-1 (3), 93.3–118.4 mm LCF (81.4–104.1 mm SL), Gaffneys Creek, Woods Point / Jamieson Road , Knockwood , 37° 25' 42”S 146° 13' 55”E, D.J. Harrington and J.A. McKenzie, 12 June 1985 ; NMV A.30242-1 (3), 60.6–95.2 mm LCF (52.2–84.9 mm SL), Kalatha Creek, Kalatha Road, Toolangi State Forest , 37° 29' 36”S 145° 32' 12”E, TAR, 18 September 1998 ; AMS I.44803-001 (1), 80.9 mm LCF (71.1 mm SL), Kalatha Creek , same location as NMV A.30242-1, TAR, 18 June 2002 ; NMV A.30254-1 (2), 59.9–92.9 mm LCF (50.8–79.4 mm SL), Keppel Hut Creek, tributary, Upper Taggerty Road, Lake Mountain , Yarra Ranges National Park , 37° 28' 36”S 145° 51' 02”E, JPO and J.A. McKenzie, 28 November 1990 ; NMV A.30268-1 (7) 53.2–109.0 mm LCF (45.4–93.0 mm SL), Keppel Hut Creek , same location as NMV A.30254-1, PJU and TAR, 5 February 1991 ; NMV A.30257-1 (4), 95.4–101.4 mm LCF (81.4–88.0 mm SL), Keppel Hut Creek, north tributary, at Upper Taggerty Road, Lake Mountain , Yarra Ranges National Park , 37° 28' 13”S 145° 51' 02”E, PJU, 10 February 1991 ; NMV A.30245-1 (3), 73.4–89.8 mm LCF (64.4–79.1 mm SL), Luke Creek, Klondyke Road, Toolangi State Forest , 37° 28' 13”S 145° 29' 46”E, TAR, 10 September 1998 ; AMS I.44802-001 (1), 87.9 mm LCF (76.6 mm SL), Luke Creek , same location as NMV A.30245-1, TAR, 18 June 2002 ; NMV A.7854 (27), 48.0– 132.2 mm LCF (42.4–114.9 mm SL), NMV A.7858 (2), 71.7–83.3 mm LCF (62.5–73.1 mm SL), and NMV A.7870 (1), 73.8 mm LCF (63.4 mm SL), Mountain Creek, 1 mile east of Kinglake , (?) 37° 31' 50”S 145° 21' 06”E, R.S. Frankenberg, P. Holbeche, P. Rogan, 6 May 1966 ; NMV A.30258-1 (5), 62.4–115.5 mm LCF (52.9–100.0 mm SL), Perkins Creek, Perkins Creek track, north-west of Woods Point , 37° 34' 22”S 146° 12' 22”E, JPO and J.A. McKenzie, 20 November 1990 ; NMV A.30252-1 (1), 98.5 mm LCF (86.2 mm SL), Keppel Hut Creek , same location as NMV A.30258-1, TAR, 8 April 2003 ; NMV A.7935 (17), 51,0– 106.1 mm LCF (43.4–92.2 mm SL), Pheasant Creek, Bartlett Track, west of Woods Point , 37° 35' 02”S 146° 12' 25”E, F. Seymour, N. Armstrong, R.H. Kuiter and B. Crockford, February 1982 ; NMV A.30261-1 (7), 48.5–110.8 mm LCF (41.3–96.2 mm SL), Pheasant Creek , same location as NMV A.7935, W.G. O’Connor and J.D. Koehn, 8 December 1987 ; AMS I.44804-001 (1), 79.2 mm LCF (69.4 mm SL) and NMV A.30264-1 (7), 41.8–98.9 mm LCF (35.9–86.9 mm SL), Pheasant Creek , same location as NMV A.7935, JPO and J.A. McKenzie, 20 November 1990 ; NMV A.30251-1 (2), 102.9–118.1 mm LCF (88.2–102.3 mm SL), Plain Creek, Plain Creek Track, north of Mirimbah , 37° 03' 59”S 146° 23' 30”E, S.R. Saddlier, 9 December 1998 ; NMV A.30238-1 (1), 57.8 mm LCF (48.5 mm SL), Plain Creek, tributary, Plain Creek Track, north of Mirimbah , 37° 04' 41”S 146° 23' 37”E, S.R. Saddlier, 9 December 1998 ; NMV A.30246-1 (2), 113.8–118.9 mm LCF (100.6–103.6 mm SL), Plain Creek , same location as NMV A.30251-1, TAR, 16 May 2001 ; NMV A.30241-1 (1), 46.9 mm LCF (40.7 mm SL), Plain Creek , same location as NMV A.30251-1, P.S. Fairbrother, 3 December 2002 ; NMV A.4848 (2), dried, Quartz Creek, above falls, upstream of Quartz Creek Road, south of Rubicon , 37° 24' 34”S 145° 51' 51”E, J.P. Beumer, 26 January 1980 ; NMV A.30244-1 (2), 94.2–104.8 mm LCF (92.8–92.0 mm SL), Robertson Gully, Falls Road, Marysville , 37° 30' 54”S 145° 44' 58”E, TAR, 11 December 1998 ; NMV A.30263-1 (3), 72.5–91.7 mm LCF (63.2–81.2 mm SL), Robertson Gully, Kings Road, Marysville , 37° 30' 49”S 145° 44' 51”E, TAR, 11 December 1998 ; NMV A.30266-1 (12), 57.0– 119.9 mm LCF (49.1–105.6 mm SL), Rubicon River, Quartz Link Track , 37° 25' 53”S 145° 51' 21”E, TAR, 20 February 1995 ; NMV A.30255-1 (8), 64.5–109.0 mm LCF (56.1–94.5 mm SL), Rubicon River , same location as NMV A.30266-1, TAR, 18 May 1995 ; NMV A.30256-1 (7), 46.3–92.9 mm LCF (40.1–82.1 mm SL), Rubicon River , same location as NMV A.30266-1, TAR, 24 May 2001 ; NMV A.30239-1 (5), 43.9–105.9 mm LCF (37.7–93.2 mm SL), S Creek, Ash Creek track, north-east of Narbethong , 37° 26' 44”S 145° 35' 40”E, JPO, 6 March 1997 ; NMV A.30259-1 (3), 42.6–98.7 mm LCF (37.7–85.4 mm SL), S Creek, same location as NMV A.30239-1, TAR, 6 August 1997 ; NMV A.30240-1 (8), 76.9–131.8 mm LCF (66.7–116.1 mm SL), Stanley Creek, Circuit Road, Mt. Stirling, 37° 08' 18”S 146° 31' 35”E, PJU, 24 April 1992 ; NMV A.30262-1 (5), 68.7–108.0 mm LCF (59.4–94.4 mm SL), Stanley Creek , same location as NMV A.30240-1, TAR, 15 May 2001 ; NMV A.30265-1 (1), 123.4 mm LCF (105.5 mm SL), Stony Creek, Plantation Road, west-north-west of Narbethong , 37° 31' 24”S 145° 35' 48”E, TAR, S.R. Saddlier, 18 September 1998 ; NMV A.30263-1 (5), 63.3–107.9 mm LCF (54.9–94.6 mm SL), Sunday Creek, Main Mountain Road, east of Wallan , Mount , Disappointment State Forest , 37° 23' 36”S 145° 08' 56”E, J. Lieschke, 28 November 2005 ; NMV A.30248-1 (11), 65.7–110.1 mm LCF (56.4–96.4 mm SL), Sunday Creek , same location as NMV A.30263-1, TAR, 7 December 2005 ; NMV A.30260-1 (2), 104.6–105.9 mm LCF (91.4–92.2 mm SL), Taggerty River, Upper Taggerty Road, Lake Mountain , Yarra Ranges National Park , 37° 29' 23”S 145° 51' 37”E, JPO and J.A. McKenzie, 28 November 1990 ; NMV A.30253-1 (7), 67.0– 103.6 mm LCF (57.3–89.6 mm SL), Taggerty River , same location as NMV A.30260-1, TAR, 5 February 1991 ; NMV A.30250-1 (5), 65.7–141.4 mm LCF (55.9–123.2 mm SL), Torbreck River, tributary of south branch, Lower ( South ) Torbreck Road , east of Lake Mountain , 37° 29' 18”S 145° 55' 10”E, TAR and PJU, 26 February 1991 ; NMV A.8126 (3), 77.3–92.3 mm LCF (67.3–79.4 mm SL), Whitehouse Creek, Lady Talbot Drive, north-east of Marysville , Yarra Ranges National Park , 37° 28' 09”S 145° 48' 57”E, N.A. O’Connor and P.S. Lake, 19 February 1986 .

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

Diagnosis. Galaxias fuscus differs from all other species within the Galaxias olidus complex by a combination of the following characters: a distinctive overall colour ranging from dull to moderately bright orange, yelloworange to reddish orange; body pattern generally absent except sides of trunk with a series of large, distinctive, dark bars surrounded by halos present, generally centred on the lateral line, relatively widely spaced and extending from above the pectoral fin base to above the pelvic fin base, very rarely faint blotches also on dorsal surface; dorsal surface of trunk broadly flattened anteriorly from above pelvic fin bases; caudal peduncle very deep (7.2–10.4 % SL); long caudal fin (12.1–19.2 % SL), much longer than caudal peduncle; long anal fin (14.2–18.6 % SL); large pectoral and pelvic fins (11.4–17.6 and 9.5–16.2 % SL, respectively); pelvic fins set far back (pre pelvic length 53.4 % SL); large bulbous head, length 21.0–26.7 % SL and longer than PelAn distance, relatively wide and deep (56.7–75.6 and 35.5–53.3 % HL); nostrils short, not visible from ventral view; mouth large, with long upper and lower jaws (33.9–46.7 and 30.2–43.6 % HL respectively) and wide gape (34.3–53.9 % HL); most posterior extent of mouth about 0.8 ED below ventral margin of eye; 0–1 pyloric caecae, short (1.0 % SL) when present; and, anal fin origin usually under 0.78 distance posteriorly along dorsal fin base.

Description. As for the genus and members of the Galaxias olidus complex, except as indicated below, based on 137 specimens, 48.5–123.2 mm SL, and 50 additional, non-type specimens for meristics. Holotype and paratype examined; as they have dried out, no morphometric measurements were undertaken though all meristic counts could be made except number of pyloric caecae. See Tables 4 to 9 for frequencies of meristic values and Table 17 for a summary of meristic variation. Segmented dorsal fin rays 10 (9–11), of these 8 (7–9) branched and 2 (1–3) unbranched; segmented anal fin rays 11 (10*–12), of these 8 (7–10; [8*]) branched and 2 (1–3) unbranched; caudal fin rays 16 [17*]; segmented pectoral fin rays 15 (14–16), of these 13 (12–14; [13*]) branched and 2 (2–3) unbranched; pelvic fin rays 7 (7–8), of these 6 (6–7) branched and one unbranched; gill raker total count (lower limb and upper limb) 12 (11–14; [13*]), lower arch with 9 (8–10) and 3 (3–5; holotype 4) on upper, variation on first gill arch 7+2 (2), 7+3 (4), 7+4 (1), 8+2 (3), 8+3 (37), 8+4 (19), 8+5 (2), 9+2 (2), 9+3 (33), 9+4 (42*), 9+5 (9), 10+2 (1), 10+3 (6), 10+4 (13), 10+5 (5), 10+6 (1), 11+3 (1), 11+4 (1), 11+5 (3); vertebrae 54 (52–56; holotype 53); 0–1 pyloric caecae on stomach.

See Table 18 for comparative value ranges of morphometric characters. Body large, elongate and deep, dorsal surface usually broadly flattened anteriorly from above pelvic fin bases, depth through pectoral base 1.2 (1.0–1.3) that through vent, trunk with dorsal and ventral profiles evenly arched from snout to dorsal fin, dorsal profile sometimes less so, occasionally almost straight, body tapering back to a moderately long, 7.4 (6.3–9.1) in SL, and deep, 11.1 (9.6–13.9) in SL, caudal peduncle, the peduncle depth 1.5 in its length; accessory lateral line present. Head distinctly large, long, 4.2 (3.7–4.8) in SL, usually similar to PelAn distance (0.8–1.3), relatively deep and wide, 2.3 (1.9–2.8) and 1.5 (1.3–1.8) in HL respectively, distinctly wider than deep (depth 1.5 (1.4–1.6) in HW), lateral profile obtuse to bulbous, particularly in larger individuals; eyes of moderate size to smallish, 5.5 (4.6–7.2) in HL and 2.4 (1.7–3.4) in HD, situated relatively high on head but distinctly below dorsal head profile, interorbital convex, wide, 2.5 (2.1–3.1) in HL and 2.2–2.3 times ED, very broad in larger individuals; cheeks expanded below eyes, eye profiles usually not visible laterally from ventral view; snout of moderate length, 3.4 (2.1–4.2) in HL and 1.6 (1.2–2.9) times ED, lateral profile bluntly rounded; post-orbital head length of moderate length, 1.9 (1.7–2.2) in HL; nostrils usually short and not visible anterio-laterally from ventral view; mouth generally terminal, large, 2.5 (2.1–2.9) in HL, posterior extent reaching back to below middle of eyes or farther and 0.8 (0.5–1.2) ED below ventral margin of eye, most anterior tip of upper lip level with middle of eye, gape wide, 2.3 (1.8–2.9) in HL, width always greater than length of upper jaw and 1.5 (1.4–1.6) in HW. Jaws subequal, lower slightly shorter (1.1 in UJL). Pyloric caecae short, usually 1.0 % SL (0.6–3.2 %); gill rakers stout, short to moderately long and bluntly to sharply pointed.

Median 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, dorsal base usually 0.9 in length of anal base, fins rounded and relatively long, middle rays longest, about equal in length; anal fin origin usually under 0.7 (0.5–1.1) distance posteriorly along dorsal fin base. Pelvic fins large, 8.1 (6.2–10.5) in SL, paddle shaped and 0.8–0.9 of pectoral fin length, usually inserted just posterior to mid-point of standard length and extending about 0.54 (0.39–0.67) distance to anal fin base; pectoral fins large, long, 7.2 (5.7–8.8) in SL, broad and rounded, extending about 0.45 distance to pelvic fin base, low on body with dorsal extent of fin base level with posterior extent of mouth, lamina of paired fins oriented ventrally, raised lamellae present on ventral surface of rays, usually strongly developed. Caudal fin long, 6.7 (5.2–8.3) in SL, weakly to strongly emarginate, occasionally truncate, 1.1–1.2 times length of caudal peduncle, vertical width of expanded rays greater than body depth through pectoral fin base, flanges moderately high and developed along caudal peduncle, relatively long but variable in length, reaching to distal end of adpressed anal fin rays or further anteriorly, often almost to fin base.

Size. Recorded to 165 mm LCF and 30 g; commonly to 80–105 mm LCF.

Colour in life. Base colour of head and body a dull to moderately bright yellow-orange, red-orange to orange, becoming lighter ventrally; belly light yellow-orange to cream. Head and upper portion of body usually overlain by a dusky shading of very fine pale dark brown to dark grey stippling, usually extending down sides to near lateral line and becoming paler; lips usually light grey, sometimes dark grey.

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Most distinctive feature is a series of large, vertical, variably shaped, roughly ovoid to elongate bars ( Figs. 13d , 14 ) located mid-laterally and extending above and below the lateral line. The number, shape, size and location of bars vary within and between populations and between the two sides of individual fish. Bars are deep black to rich burgundy black, usually solid though some are occasionally slightly faded, surrounded by a narrow, light halo composed of the base body colour without a dusky hue. Halos of adjacent bars are usually separated though may partially join when bars are closely spaced. Bars are usually wider with a rounded end above the lateral line, becoming narrower and pointed below (inverted ‘tear-drop’ shape), or widest at the lateral line. From 0 to about 10 bars can be present, usually 7 or less, fully formed or partial; partial bars usually short but generally as wide as full bars, circular to ovoid, situated on the upper sides and extending down to the lateral line. Bars always located between the upper margin of the opercle, above and forward of the pectoral fin base, extending posteriorly to just before the dorsal fin base. Occasionally very faint, widely spaced, grey blotches extend farther posteriorly, onto the caudal peduncle. Bars, blotching or spotting absent from dorsal surface, except rarely when large, faint, discrete roundish blotching present, extending posteriorly from posterior edge of nape to about above pelvic fin base, interspersed in areas between lateral bars, some extending over dorso-lateral margin onto very upper lateral surface, again dispersed between lateral bars. Pattern and bars absent from head.

Mid-dorsal surface of trunk usually with thin, single to double, row of gold flecks extending from nape posteriorly to dorsal fin base; dorsal and dorso-lateral surface of trunk also with moderate sprinkling of gold flecks, extending down sides to top of lateral bars, occasionally also extending onto top of head and snout and onto cheeks; sides of caudal peduncle sometimes with wash of gold flecks. Gill cover translucent, sometimes with a small golden patch; iris golden. Fins usually translucent light grey, yellowish grey to pale orange. Fish smaller than about 50–55 mm LCF usually lack bars and are a dull grey to grey-brown overall.

Colour of preserved material. Head and body fade to an overall pale lemon yellow to tan base colour, overlaid by a dusky light to moderately dark, grey to black hue, darkest mid-dorsally, gradually lightening down the sides. Ventral surface light cream to creamy yellow, lacking duskiness. Dorsal portion of nape, head and snout, and dorso-anterior portion of upper jaw with dusky hue, becoming paler ventrally and extending downward onto preopercle, opercle, lower jaw and below eyes.

Eye black, pupil translucent pale orange-yellow or brownish yellow. Teeth translucent yellow to pale orangeyellow, tips orange to orange-red; gill rakers creamy white to pale yellow. Fins generally translucent yellow, becoming transparent to clear on posterior margins, fleshy bases of pelvic and pectoral fins light lemon yellow. Fin rays transparent, anterior edges of first few rays edged with brown. Most distinctive marking, present even on faded specimens, is the series of large black bars along mid-lateral portion of the body (see Colour in life, above).

Dried out specimens (i.e. holotype and paratype) orange-brown to dark brown, slightly lighter ventrally. Caudal peduncle yellow brown and partially translucent. Eye black to blackish purple, bars on sides black, partially faded, fins clear to slightly yellowish (see Fig. 13a ).

Etymology. The species name is derived from the Latin, fusc, meaning brown, dark, dusky or tawny. Mack (1936; p. 101) described the colour of the holotype and paratype as greenish brown, but this is similar to the colouration of the many preserved individuals within the Galaxias olidus complex. Possibly Mack was referring to the distinctive and dark bars on the sides of the body which he referred to as “..prominent dark oval blotches..”. The live colouration of the majority of Galaxias fuscus is a dusky orange-brown, and the type material is currently also a tawny colour, hence the species name is apt.

Genetics. Allozyme and mtDNA analysis of this species can be found in Adams et al. (2014; taxon code FU). Diagnostic allozyme loci (5–13) between this taxon and the other species in the Galaxias olidus complex are provided in Table 12.

Distribution. See Fig. 11 . Endemic to the Goulburn River system in central Victoria, on the Murray–Darling Basin side of the Great Dividing Range. Now restricted to a small upland area extending along the south-eastern portion from the Delatite River system in the north-east, southward to the upper reaches of the Goulburn River near Woods Point, and then westward to a hybrid population (see Ayres et al. 2012b) in the Sunday Creek system near Mount Disappointment, just north of Melbourne ( Raadik et al. 2010), at an elevation between 400–1600 m asl. Now extinct in the lower Rubicon River (Rubicon), Gaffneys Creek (A1 Mine Settlement), Whitehouse Creek (NE Marysville), and Mountain Creek (Kinglake).

Sympatry. Found with Galaxias olidus at one site (Raspberry Creek, Woods Point) though considered to have been sympatric with other populations before alien trout severely fragmented populations and substantially altered distributional patterns. Also considered to have been historically found with Galaxias arcanus sp. nov., and very possibly with Galaxias oliros sp. nov. at the very downstream extent of its range.

Habitat. See Raadik et al. (2010) for detailed description. Briefly, found in small to medium-sized (0.7–11.0 m average width), moderately to fast flowing, steep gradient, shallow (0.1–0.4 m average depth), creeks and rivers, all typically cool to cold. Stream substrate consists of bedrock, boulder, cobble, with smaller amounts of pebble, gravel and sand, and streams are usually well shaded by dense overhanging riparian vegetation. Instream habitat usually consists of accumulations of large and small timber debris, rocks and tree roots in undercut banks.

General Biology. Relatively well covered by Raadik et al. (1996, 2010), Shirley and Raadik (1997) and Stoessel et al. (2012). In brief, non-migratory and completes its entire life cycle in freshwater and collected at a density ranging from 0.1–1.2 fish/m 2 in the absence of trout. Diet consists mostly of aquatic and terrestrial insects, with fish foraging off the bottom and mid water in pools and at the end of riffle/glide sections. Often the only freshwater native fish in the systems it occupies and usually found with Central Highlands Spiny Crayfish. Very occasionally also recorded with the native species Galaxias olidus and Gadopsis bispinosus . Spawning occurs from late September to early October, though males can be running ripe from about April, and females ripe from mid- June. Fecundity is low (mean approx. 500 eggs); eggs are adhesive, about 2.2 mm diameter, and laid on the side or underneath large rocks in fast-flowing, shallow water. Hatching occurs after about a month, and newly-hatched larvae are about 8–12 mm in length. Growth rates are slow, and adults live to about 15 years of age. Able to survive in very cold water (<3 o C) during winter, with populations at higher elevations in streams draining catchments which are usually covered by snow for varying periods of time. Populations between Marysville and Sunday Creek found to be infected with small dark brown to black cysts, possibly trematode metacercariae, embedded in the skin, fins, and sometimes in the eyes.

Variation. Mid-lateral bars vary geographically ( Fig. 14 ), and are very occasionally absent, though this is extremely rare. Bars on fish from around Lake Mountain are the largest. Putative hybridisation with Galaxias olidus can cause difficulties in the identification of some individuals (see below).

Conservation status. Endangered ( DSEWPC 2013), critically endangered ( IUCN 2012, DSE 2013); protected under the national Environment Protection Biodiversity Conservation Act 1999 and Victorian Flora and Fauna Guarantee Act 1988.

Remarks. This species has the most distinctive colour pattern of all taxa in the Galaxias olidus complex: black, generally long and wide, ovoid to inverted tear-shaped, and restricted to an area extending from the rear of the operculum to about the origin of the pelvic fin.

Previously considered a junior synonym of Galaxias olidus Günther, 1866 ( McDowall & Frankenberg 1981). Originally described from two specimens in poor condition from the Rubicon River ( Mack 1936), the holotype and paratype were noted to be “...completely dehydrated...’ by McDowall & Frankenberg (1981: 475) and are currently in very poor condition (shriveled). The length of the Holotype was listed as 84 mm TL when described ( Mack 1936) (see Appendix 1) but is now 74.9 mm LCF, possibly having dried out or deteriorated further over time. Contrary to McDowall & Frankenberg (1981), who stated the types were useless, the prominent bar pattern is still visible on each and specimen condition is sufficient to enable counts to be made of fin rays and gill rakers.

In an unpublished revision of Australian Galaxiidae, Frankenberg (1969) was unable to find additional specimens for comparison from the type locality but located a second population at Kinglake, approximately 50 km south-west. Based on comparison of the new material with Galaxias olidus s.l., the nominal species Galaxias fuscus was retained as a subspecies of G. olidus s.l. ( Frankenberg 1969). A subsequent, more detailed revision ( McDowall & Frankenberg 1981) considered G. fuscus a colour pattern variant of G. olidus s.l., rejected its status as a distinct species or subspecies and considered it a junior synonym of Galaxias olidus Günther, 1866 .

The ‘ fuscus ’ form of Galaxias olidus s.l. was re-discovered in 1980 near Woods Point ( Armstrong 1993), approximately 35 km south-east of the original type locality and additional survey work in the late 1980s to early 1990s located additional sites. Considered extinct from its type locality, it was rediscovered in headwater reaches of the Rubicon River in the mid 1990s.

Whilst dried out, the holotype could still be adequately compared with recent material as all but one meristic character could be enumerated and it retains a number of additional distinctive characteristics (large fins, distinctive colouration, dark bars, etc.). Galaxias fuscus is known to hybridise with Galaxias olidus with putative hybrid fish identified from amongst both parents in Raspberry Creek and the entire population at Sunday Creek appears to be composed of hybrids. Suspected putative hybrid individuals range in colour from the typical orange to a dull yellow and appear to possess obvious or pale blotching on the dorsal surface of the trunk. Black bars are present along the sides but these are smaller (narrower and shorter), and often more bars are present extending farther posteriorly, sometimes onto the caudal peduncle; bars usually fade in intensity posteriorly.

A cold-adapted fish, usually found in very heavily shaded streams which rarely exceed 15 o C during summer and usually reach 1–3 o C during winter. This species is considered to have previously occupied larger, deeper and more moderate gradient river systems at lower altitudes (down to about 300 m elevation), with a coarser substrate and larger accumulations of timber debris. The enlarged lateral canine teeth reported in this species ( Allen 1989, Armstrong 1993) could not be confirmed from 188 specimens examined from all populations. They are therefore considered absent. The distinctive mid-lateral bars differ to those on the conspecific Galaxias olidus by being wider and longer (up to 4 mm wide, 10 mm long), fewer in number and more widely spaced, and restricted along sides to between the posterior end of the head and the origin of the dorsal fin base (extend farther in G. olidus ). Fish in captivity have been reported to rapidly alter the number of bars (P.L. Cadwallader, pers. comm. 1993; G.N. Backhouse, pers. comm. 2004), though this has not been observed in over 10 years of keeping captive fish from a much larger number of individuals and populations. This anomalous report may have been due to confusing poorly identified individual fish.

The original specimens, which were described as Galaxias fuscus in 1936, were in poor condition when they were received at the Museum of Victoria ( Mack 1936) and an attempt was made to secure more from the collector. Reproduced below is a transcript of a copy of a letter written by George Mack, Curator, National Museum of Victoria, to A.C. (Archibald) Payne who collected the specimens and donated them on 18 April 1935. This copy was located in the historical letter file of the Department of Ichthyology, Museum Victoria in 1986; original copy and letter file now missing.

Mr A. C. Payne

April 27th 1935 Tin Hut,

Rubicon,

Victoria

Dear Sir,

The two small fishes forwarded by you for identification, through Mr C. French, are referable to the genus Galaxias , but they appear to differ from the known species. Both examples were in poor condition when received and to permit a definite determination to be made it would be necessary to have additional fresh specimens. If you could undertake to obtain some we would be greatly obliged, and we would send you one or two small bottles containing proper preserving fluid. Before forwarding these we would be pleased to hear from you, and an envelope, stamped and addressed, is enclosed for your reply.

We are always prepared to pay postage charges on specimens forwarded.

Yours truly,

G. Mack

It appears that Archie Payne did not send additional specimens and it is unknown if he received or replied to Mack’s letter. The description of Galaxias fuscus was published the following year, based on the two original ‘poor’ specimens. The actual state of the specimens is difficult to determine, as Mack provides little detail, and confusingly, his line drawing of the holotype suggests a specimen in relatively good condition. Mack may have used artistic licence to depict the holotype as he thought it may have been when alive. Whether the specimens were as dried as they are now (see Fig. 13a ), or dried to this extent later, is unknown.

The type locality is given as ‘Rubicon River’ ( Mack 1936) and this information may have been supplied by the collector, Archie Payne, or inferred by Mack from the postal address for Payne (‘Tin Hut, Rubicon’). Tin Hut is the local name for the original Rubicon Township which was situated at the junction of the Rubicon River and its main tributary, the Royston River. The exact location of collection will never be known, but may have been at Tin Hut in the Rubicon or Royston rivers, in Flea Creek which ran through the old township, or elsewhere in the catchment, as Archie Payne is known to have lived farther upstream in the mid reaches of the Rubicon River system, at the original Lumber Co. mill site ( Evans 1994), which was located just upstream of the existing Royston Power Station. Archie Payne died in the Black Friday fires on 10 January 1939, defending timber mill machinery on a ridge near a tributary of the Rubicon River ( Evans 1994). Unlike its discoverer, Galaxias fuscus survived the 1939 fires, and those of 2006- 7 in the east of its range and the large fires of February 2009 which re-burnt the Rubicon River catchment 70 years on.

Figures

FIGURE 11. Distribution of Galaxias arcanus sp. nov. (black circles) and Galaxias fuscus (open circles). (river basins shown—refer to Fig. 1).

FIGURE 13. A) Galaxias fuscus holotype (NMV A.96), right side (T.A. Raadik); B) G. fuscus Rubicon River (NMV A.30266- 1), female, usual bar pattern, and C) G. fuscus Keppel Hut Creek (NMV A.30257-1), female, alternate bar pattern showing some partial bars (R. Plant); D) G. fuscus, Falls Creek, Mount Stirling, 21 February 2007; ~ 85 mm LCF (T.A. Raadik); and E) habitat of G. fuscus, Keppel Hut Creek, Lake Mountain, June 1992 (T.A. Raadik). Scale bar = 5 mm.

FIGURE 14. Variation in bar pattern in Galaxias fuscus from across their range. Clockwise from top left: Plain Creek (Delatite system); Brewery Gully (Goulburn system); Torbreck River tributary, (Big system); Keppel Hut Crk and Robertsons Gully (Leary’s Creek) (Steavenson system); Luke Crk (Yea River system); All images by T.A. Raadik, except Torbreck R (M. Shirley).