Galaxias olidus, Gunther, 1866

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 : 23-26

Galaxias olidus complex

Diagnosis. Anal fin origin posterior to that of dorsal fin and usually set back under 40 % or more of length of dorsal fin base; body moderately thick to stout; caudal peduncle always longer than deep; accessory lateral line usually present; head moderately wide to broad, wider than deep; interorbital broad and usually flat, about twice eye diameter or greater; snout profile from above and below evenly rounded without obvious inflections; mouth usually reaching under first third to middle of eye, occasionally to anterior margin, and regularly> 0.5 eye diameter below eye; dorsal and anal fin bases usually fleshy and fins usually of similar length, anal fin base usually longer; pectoral fin always longer than pelvic fin, oriented anterio-ventrally to ventrally, pectoral fin base about level with posterior extent of mouth; caudal fin usually emarginate, occasionally truncate or weakly forked, fin lobes rounded; caudal peduncle flanges often reach at least to adpressed anal fin rays; gill rakers usually stout and short to moderate length, always shorter than diameter of eye; pyloric caecae, when present usually stout.

Description. Members of the Galaxias olidus complex, which includes Galaxias olidus s.s., Galaxias fuscus and Galaxias ornatus , and the 12 species described below, are distinguished by the following combination of characters: relatively small (70–165 mm LCF); body of moderate length to elongate, usually ovoid in cross-section, but often a little dorsally compressed, less often laterally, and moderately thick to stout (10–16 % SL), with depth through the pectoral fin base almost equal to, or usually greater (108–137 % BDV) than, that through the vent; standard length from 88–90 % of caudal fork length; dorsal and ventral profiles of body usually relatively evenly arched from snout to anal fin, though ventral occasionally straight; body tapering back to a moderate to relatively long (11–16 % SL) and deep (7.0–9.0 % SL) caudal peduncle, the peduncle always longer than deep; belly deepened in maturing individuals. Lateral line mid-lateral; accessory lateral line usually present, often indistinct, extending along dorso-lateral margin to near dorsal fin base.

Head moderately long (20–24 % SL) and deep (35–47 % HL), usually about 90–93 % of the Pelvic-Anal (PelAn) distance though sometimes shorter or longer, moderately wide to broad (55–69 % HL) and distinctly wider than deep (133–171 % of HD), lateral profile rounded or bulbous to wedge shaped, sometimes distinctly flattened dorsally; eyes relatively small to moderate size (16–21 % HL), oriented laterally, situated moderately high on head, at or just below dorsal head profile, interorbital broad (35–42 % HL) and flat, occasionally slightly concave or convex, usually greater than twice diameter of eye; snout short to moderate length (25–31 % HL), 1.2–1.5 times diameter of eye, lateral profile rounded to pointed, profile from above and below evenly rounded without obvious inflections, most anterior extent of snout usually level with middle of eye; posterior opercular margin usually extending as a fleshy flap onto pectoral fin base, occasionally reaching base of fin. Mouth moderately long (27–39 % HL), usually reaching back below first third to middle of eyes, though sometimes to front of eye or farther back, regularly 0.6–0.8 ED below ventral margin of eye, wider than long, cleft usually oblique, anterior tip of upper lip usually about level with ventral margin of eye or higher; gape moderate to relatively broad (31–45 % HW). Jaws either relatively equal, with lower very slightly shorter, or subequal and lower distinctly shorter than upper (73–95 % UJL); single row of conical teeth in jaws, without enlarged canines; mesopterygoidal teeth moderately strong.

Pyloric caecae absent, 1 or 2, if present ranging from very short to moderately long (1.0–5.1 % SL); if two caecae present, one usually shorter. Gill rakers (total count usually 11–16) short to moderately long and typically stout, always less than diameter of pupil, rounded to bluntly or sharply pointed, usually 8–11 along lower arch (including raker in angle of arch) and 2–5 on upper arch. Vertebral count usually from 49–58. Disposition of laterosensory pores on head as in most Galaxias (see McDowall 1970a, 1997a, McDowall & Frankenberg 1981); disposition of sensory papillae defined in Fig 5 .

Fins generally fleshy at bases and extending across about 0.5 of fin surface; dorsal fin (usually 8–11 segmented rays) and anal fin (9–13 segmented rays) similar and usually with two (range 1–3) unbranched, segmented rays anteriorly, bases of fins of moderate size, anal fin base usually longer than dorsal fin base, fins short to moderate length and rounded, middle rays usually longest; anal fin origin posterior to that of dorsal fin, set back under 40–85 % (range 18–120 %) of length of dorsal fin base. Pelvic fins usually with 7 segmented rays, some species with 8, of moderate size (9–12 % SL), origin at about mid-point of standard length, distinctly shorter than pectoral fins (74–92 % PecL); pectoral fin usually with 12–16 segmented rays, moderately large (11–15 % SL) and typically paddle-shaped, with two, occasionally 1 or 3, unbranched segmented rays anteriorly, relatively low on body, most dorsal extent of fin base usually level with posterior extent of mouth, well below lateral midline of head and below ventral margin of eye; laminae of paired fins oriented anterio-ventrally to ventrally, often with weakly to welldeveloped raised lamellae on ventrally facing surface along the distal end of the first few rays. Caudal fin with 16 principal caudal rays, rarely 15 or 17, usually emarginate, occasionally truncate to almost forked, fin lobes rounded, length to caudal fork 11.5–15.0 % SL; caudal peduncle flanges usually moderately developed, either short to long along caudal peduncle, just reaching or extending anteriorly past adpressed anal fin.

Morphological key to species in the Galaxias olidus complex

Due to morphological conservatism in this complex, and the degree of within-species variation of various morphological characters, ambiguities in some identifications will remain using the following key. The accuracy of specimen identification can be improved by examination of combinations of multiple characters and careful and detailed comparison with all characters in the species diagnoses and descriptions. This includes external characters, but importantly, also the internal characters of pyloric caecae and gill rakers. Identification can be further improved by inclusion of the geographical location of the collection site, if known, to reduce the potential list of possible species, as many taxa are allopatrically distributed. The combination of multiple, relatively indiscrete external characters, and use of internal characters, will make field identification difficult, and in many instances will require collection of 10 % formalin fixed voucher material for later verification in the laboratory and a lateral profile image of live specimens.

Ethanol preserved material is unsuitable for identification of the majority of species within this complex as most of the subtly differing morphometric features are affected by shrinkage, which significantly increases the chance of error in correct identification. Further, accurate counts of fin rays can be difficult following ethanol preservation as fins usually collapse and shrink and become brittle and difficult to ‘fan’ open.

The key is designed for use primarily with adult specimens as morphometric characters may differ in the juvenile stage. A minimum length is not provided as one species is diminutive, with the length of younger adult fish falling below what would usually be considered an appropriate minimum length (50 mm LCF). The majority of couplets in the key are based on combinations of characters which increase the accuracy of the key. Characters are separated in the text by a semi-colon, are not hierarchical, and consequently their order is not relevant.

Based on a significant, but only partially diagnostic character, two species appear twice in the following key.

1 One or more distinct, black, very dark grey or dark brown, elongate vertical bars (as opposed to diffuse and irregular shaped brown, brownish grey to dark brown blotches), usually much longer than wide and not centred inside a mid-lateral blotch, present along the lateral midline.......................................................................... 2

- Mid-lateral bars not as above, or if present, usually small and black, circular or slightly ovoid (as opposed to medium or large, distinct and elongate).................................................................................. 4

2(1) Mid-lateral bars large, black, generally long and wide, ovoid to inverted tear-drop shape, often surrounded by a lighter halo, relatively widely spaced and located between the pectoral and pelvic fin bases; pattern usually lacking from dorsal surface of trunk; gape wide (> 41 % HL); head length typically greater than PelAn distance (HL/PelAn ratio usually> 106 %); body often orange, orange-red or orange-brown................................................. Galaxias fuscus Mack, 1936

- Mid-lateral bars not as above; pattern usually often present on dorsal surface of trunk; gape width <41 % HL; head length typically shorter than PelAn distance (HL/PelAn ratio usually <106 %); body usually brown to yellow.................... 3

3(2) Mid-lateral bar shape variable, from elongate and very narrow, ovoid to almost round, small to moderate sized, becoming paler (and grey or brown) posteriorly, bars often closely spaced and extending posteriorly well past pelvic fin base; LDB/LAB ration> 85 %; DL/AL ratio> 90 %; anal fin origin typically under> 55 % distance posteriorly along dorsal fin base; 1, more often 2, pyloric caeca of moderate length.......................................... Galaxias olidus Günther, 1866 (in part)

- Bars very short and narrow, usually restricted to anterior portion of lateral midline between the pectoral and pelvic fin bases, typically on or within lighter bars; LDB/LAB ration <80 %; DL/AL ratio <90 %; anal fin origin typically under <55 % distance posteriorly along dorsal fin base; usually a single, short pyloric caecum, often absent........ Galaxias oliros sp. nov. (in part)

4(1) Mouth distinctly subterminal (lower jaw shorter than upper).................................................... 5

- Mouth usually terminal or nearly so (jaws about equal or lower slightly shorter than upper)........................... 7

5(4) Snout and upper lip extended anteriorly as thick and fleshy protrubence; lower jaw distinctly shorter than upper; ventral profile of body straight; usually 7 segmented pelvic fin rays; caudal peduncle long (mean of 16.4 % SL); anal fin origin usually under 0.4 distance posteriorly along dorsal fin base (known from the upper Murray River and tributaries in inland VIC and southern NSW)........................................................................... Galaxias arcanus sp. nov.

- Snout and upper lip not as above; lower jaw not as above but shorter than upper; ventral profile of body arched; usually 8 segmented pelvic fin rays; caudal peduncle of moderate length (mean <13.5 % SL); anal fin origin under 0.5 or greater distance posteriorly along dorsal fin base.......................................................................... 6

6(5) Pyloric caecae absent; body depth at vent moderate (12.7 (11.2–14.3) % SL); anal fin long based (11.7 (11.0–12.5) % SL); segmented pectoral fin rays usually 14, sometimes 15; anal fin origin usually under 0.5 distance posteriorly along dorsal fin base; usually 55 or fewer vertebrae (known from the upper Roger River, lower Snowy River system East Gippsland, coastal VIC)................................................................................ Galaxias mcdowalli sp. nov.

- Usually 2 pyloric caecae, occasionally 1; body depth at vent shallow (10.1 (8.4–12.4) % SL); anal fin based of moderate length (9.9 (8.7–10.9) % SL); segmented pectoral fin rays usually 15 or more; anal fin origin usually under 0.8 distance posteriorly along dorsal fin base; usually 57 vertebrae (known from upper tributaries of the Snowy River on Mount Kosciuszko, Snowy River system, NSW).............................................................. Galaxias supremus sp. nov.

7(4) Caudal peduncle, caudal fin and pectoral fins short, usually <12 % SL (known from the upper Tuross River system in coastal SE NSW)..................................................................... Galaxias brevissimus sp. nov.

- Caudal peduncle, caudal fin and pectoral fins usually> 12 % SL (found outside of the Tuross River system)............. 8

8(7) Length of dorsal fin base usually equal or greater than length of anal fin base...................................... 9

- Length of dorsal fin base usually less than (<97 %) length of anal fin base....................................... 11

9(8) PelAn distance> 24.5 % SL; anal fin base usually <10 % SL; dorsal fin length usually <14.5 % SL; dorsal and anal fins set back along body usually at> 71 and> 76 % SL respectively; head depth <38.5 % HL; postorbital head length> 58 % HL; usually 53 (52–53) vertebrae (known from the upper Dargo River system in the coastal Gippsland region of VIC).......................................................................................... Galaxias mungadhan sp. nov.

- PelAn distance <24.5 % SL; anal fin base usually> 10 % SL; dorsal fin length usually> 14.5 % SL; dorsal and anal fins set back along body usually at <71 and <76 % SL respectively; head depth> 38.5 % HL; postorbital head length <58 % HL; usually 54 (54–55) vertebrae.............................................................................. 10

10(9) Usually 1, less often 2, pyloric caecae; dorsal and anal fin bases long,> 11.0 % SL; eye diameter relatively small (<17.5 % HL) and <48 % IOW; gape relatively narrow (<35.5 % HL); gill rakers moderately long; usually 9–10 segmented dorsal fin rays and 14 segmented pectoral fin rays; (known from a tributary of the lower La Trobe River system in the coastal Gippsland region of VIC)................................................................. Galaxias longifundus sp. nov.

- Pyloric caecae usually absent; dorsal and anal fin bases short, <11.0 % SL; eye diameter relatively large (<17.5 % HL) and> 48 % IOW; gape relatively broad (> 35.5 % HL); gill rakers short; usually 10–11 segmented dorsal fin rays and 15 segmented pectoral fin rays; (known from a tributary of the lower Thomson River system in the coastal Gippsland region of VIC)................................................................................... Galaxias lanceolatus sp. nov.

11(8) Body stocky and deep, depth at vent> 13.5 % SL, depth through pectoral fin base> 15.5 % SL; typically 10 gill rakers on first gill arch; caudal peduncle depth usually> 8.8 % SL; gape width> 43 % HL and> 64 % HW (restricted to the very upper Murrumbidgee River system in inland NSW)............................................ Galaxias tantangara sp. nov.

- Body elongate and shallow to moderately deep, depth at vent <13.5 % SL, depth through pectoral fin base <15.5 % SL; usually 12 or more gill rakers on first gill arch; caudal peduncle depth usually <8.8 % SL; gape width <43 % HL and <64 % HW ................................................................................................... 12

12(11) Snout relatively long,> 29.5 % HL and> 157 % ED......................................................... 13

- Snout short or of moderate length, <29.5 % HL and <157 % ED.............................................. 14

13(12) Segmented pelvic fin rays 8; typically 11 segmented anal fin rays; gill rakers on first arch 14 (13–15); pyloric caecae absent; nostrils normally just visible from ventral view (known from the Arte River, Bemm River system, East Gippsland, in coastal VIC)......................................................................... Galaxias aequipinnis sp. nov.

- Segmented pelvic fin rays 7; typically 10 segmented anal fin rays; gill rakers on first arch 12 (11–12); usually 1, sometimes 2, pyloric caecae; nostrils not visible from ventral view (known from an upper tributary in the Macalister River system, Gippsland, in coastal VIC)...................................................... Galaxias gunaikurnai sp. nov.

14(12) Accessory lateral line absent; dorsal and ventral trunk profiles straight or nearly so; anterior nostrils long and visible from ventral view; segmented pectoral fin rays 13; eye large,> 20 % HL and ED/HD and ED/IOW ratios> 50 and> 55 % respectively; pelvic fins small (<9.8 % SL) and PelL/PecL ratio <80 %; mean vertebral count 51 (diminutive species, average size 45–55 mm LCF; known from the Genoa/Wallagaraugh, Cann, and mid-Snowy River systems East Gippsland, coastal VIC/NSW).................................................................................. Galaxias terenasus sp. nov.

- Accessory lateral line present; dorsal and ventral trunk profiles relatively evenly arched; anterior nostrils short to moderately long and not visible from ventral view; segmented pectoral fin rays 14 or more; eye moderate, <20 % HL and ED/HD and ED/ IOW ratios <50 and <55 % respectively; pelvic fins moderate (> 9.8 % SL) and PelL/PecL ratio> 80 %; mean vertebral count usually> 52; (average size 60–90 mm LCF; distribution not as above)........................................... 15

15(14) Interorbital width <40.5 % HL; DCP/LCP ratio> 61 %; caudal peduncle length <13 % SL; rakers on first gill arch usually 12 and typically 15 segmented pectoral fin rays; 1–2 pyloric caecae of moderate length... Galaxias olidus Günther, 1866 (in part)

- Interorbital width> 40.5 % HL; DCP/LCP ratio <61 %; caudal peduncle length> 13 % SL; rakers on first gill arch usually 13 or more and typically 14 segmented pectoral fin rays; usually 1 pyloric caecum or caecae absent, if present, short to moderate length.............................................................................................. 16

16(15) Anal fin base long (> 11.0 % SL), distinctly longer than dorsal fin base (LDB/LAB ratio <83 %); BDPec/BDV ratio <114 %; anal fin origin typically under <55 % distance posteriorly along dorsal fin base; AL/LAB ratio <147 %; Pel/PelAn ratio> 48 %; LJL/GW ratio> 90 %; usually 1 very short pyloric caecum, less often absent; typically 14 gill rakers on first arch with 9 segmented dorsal fin, and 12 segmented anal fin rays; caudal fin emarginate to weakly forked (found north of the Great Dividing Range, and west of the Otway Coast basin in coastal VIC, extending into SA)......... Galaxias oliros sp. nov. (in part)

- Anal fin base of moderate length (<11.0 % SL), usually slightly longer than dorsal fin base (LDB/LAB ratio> 83 %); BDPec/ BDV ratio> 114 %; anal fin origin typically under> 55 % distance posteriorly along dorsal fin base; AL/LAB ratio> 147 %; Pel/PelAn ratio <48 %; LJL/GW ratio <90 %; pyloric caecae usually absent, less often 1 present, moderately long; typically 13 gill rakers on first arch with 10 segmented dorsal fin, and 11 segmented anal fin rays; caudal fin emarginate (known from catchments draining to the middle of Bass Strait in central, coastal VIC)................ Galaxias ornatus Castelnau, 1873

Species Treatments

See Tables 4–9 for the entire range of frequencies in counts for rays in the dorsal, anal, caudal, pectoral and pelvic fins, gill rakers and vertebrae for all species in the Galaxias olidus complex. Summarised counts and morphometric variation are provided separately under each species treatment. In each species description meristic character values are presented as a mode and value range for 90 % of specimens, holotype indicated as * if different to the modal count, [] if within or outside of range. Diagnostic allozyme loci (see Adams et al. 2014) are also provided for each species.

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Figures

FIGURE 5. Cephalic sensory pore system (open) and cutaneous sensory papillae (closed) of Galaxias spp.; a. lateral view; b. dorsal view; c. ventral view. LL1—lateral line papillae; LL2—accessory lateral line papillae; N1—anterior nostril; N2—posterior nostril; PF—pectoral fin base.