Galaxias aequipinnis, 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 : 29-37

Galaxias aequipinnis , new species

East Gippsland Galaxias

Tables 4 to 11; Figs. 6 & 7

Galaxias olidus (non G. olidus Günther, 1866 )— Cadwallader & Backhouse, 1983: 69 (partim); Raadik, 1995b: 55, fig A4.7 (partim).

Galaxias sp. 4 — DSE, 2013: 17; Lieschke et al. 2013a,b.

Galaxias sp. 17— Kuiter, 2013: 80.

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

Material Examined.

Holotype. NMV A.30565-2, 79.8 mm LCF, (70.8 mm SL), female, Arte River, at bridge on Glen Arte Road, west of Club Terrace , Murrungower State Forest , Victoria, 37° 34' 4”S 148° 45' 14”E, T.A. Raadik, 25 February 2002.

Paratypes. VIC: AMS I.44922-001 (2), 64.3–72.6 mm LCF (56.7–63.6 mm SL), NMNZ P.045752 (2), 68.5–71.1 mm LCF (60.5–62.8 mm SL) and NMV A.30565-1 (10), 64.2–85.7 mm LCF (56.3–75.8 mm SL), collected with holotype; NMV A.30567-1 (3), 69.8–89.7 mm LCF (62.0– 79.4 mm SL), Arte River , at type locality, T.A. Raadik, 28 May 1992 ; NMV A.30563-1 (6), 62.9–85.2 mm LCF (55.9–76.0 mm SL), Arte River , at bridge on Arte Road , west of Club Terrace, Murrungower State Forest, 37° 32'53”S 148° 47' 55”E, T.A. Raadik, 28 May 1992 .

Non-type material. VIC: NMV A.30567-2 (9), Arte R, collected with NMV A.30567-1.

Diagnosis. Galaxias aequipinnis sp. nov. differs from all other species within the Galaxias olidus complex by a combination of the following characters: segmented pelvic fin rays 8; pyloric caecae absent; head length relatively long (21.6–24.5 % SL), its length about as long as PelAn distance; nostrils of moderate length, usually just visible anterio-laterally from ventral view; mouth slightly subterminal and lower jaw shorter than upper; distinctive ‘blunt’ profile of snout; long anal fin base (10.4–12.9 % SL); short AL/LAB ratio, long pelvic fins which are about 0.9 of the pectoral fin length; a relatively long snout (27.2–32.0 % HL); a broadly flat dorsal midline anteriorly from above pelvic fin bases; raised lamellae rarely present on ventral surface of paired fins, if so, weakly developed; anal fin origin usually under 0.6 distance posteriorly along dorsal fin base; and, lack of black bars along lateral line.

Description. As for the genus and members of the G. olidus complex, except as indicated below, based on 24 specimens, 55.9–79.4 mm SL, and eight additional, non-type specimens for meristics. See Tables 4 to 9 for frequencies of meristic values and Table 10 for a summary of meristic variation. Segmented dorsal fin rays 10 (9–10), of these 8 (8–9) branched and 2 (1–3) unbranched; segmented anal fin rays 11 (11–12), of these 9 (9–10*) 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 (1–2) unbranched; pelvic fin rays 8, of these 7 branched and one unbranched; gill raker total count (lower limb and upper limb) 14 (12–15), lower arch with 10 (9–10) and 4 (3–5) on upper, variation on first gill arch 8+4 (1), 9+3 (2), 9+4 (3), 9+5 (1), 10+3 (5), 10+4 (11*), 10+5 (4), 10+6 (2), 11+4 (2); vertebrae 54 (52–56); pyloric caecae absent.

See Table 11 for comparative value ranges of morphometric characters. Body moderately stout and elongate, dorsal midline usually broadly flat anteriorly from above pelvic fin bases, depth through pectoral base 1.2 (1.0–1.2) that through vent, trunk with dorsal and ventral profiles evenly arched from snout to dorsal fin, somewhat depressed on head, with upper surface flattish, body tapering back to a moderately short, 7.9 (7.3–8.8) in SL, and deep, 11.6 (10.4–13.0) in SL, caudal peduncle, the peduncle depth 1.5 (1.2–1.7) in its length; accessory lateral line present. Head of moderate length, 4.4 (4.1–4.6) in SL, and similar to PelAn distance (0.9–1.1), of moderate depth and width, 2.4 (2.2–2.6) and 1.6 (1.4–1.7) in HL respectively, distinctly wider than deep (depth 1.6 in HW), lateral profile wedge-shaped and flattened dorsally; eyes of moderate size, 5.4 (4.9–6.3) in HL, 2.3 (1.9–2.7) in HD, situated high on just below dorsal head profile, interorbital slightly convex, of moderate width, 2.5 (2.2–2.7) in HL and 2.2 (2.2–2.3) times ED; cheeks expanded little below eyes, eye profiles usually visible laterally from ventral view; snout relatively long, 3.3 (3.1–3.7) in HL and 1.6 (1.3–1.9) times ED, lateral profile bluntly pointed as anterior portion of upper lip little rounded and almost vertical; post-orbital head length of moderate length, 1.9 (1.8–2.0) in HL; nostrils moderately long and usually just visible anterio-laterally from ventral view; mouth slightly subterminal, moderately large, 2.6 (2.4–2.8) in HL, posterior extent reaching back to below anterior 0.3–0.5 of diameter of eyes and 0.7 (0.6–0.8) ED below ventral margin of eye, cleft moderately oblique, most anterior tip of upper lip about level with ventral margin of eye, gape moderately narrow, 2.5 (2.0–2.9) in HL, width about equal to length of upper jaw and 1.6 (1.4–1.7) in HW. Jaws subequal, lower a little shorter (1.1–1.3 in UJL). Pyloric caecae absent; gill rakers moderately short, stout and bluntly pointed.

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Fins moderately fleshy at bases, with thickening extending distally over approximately 0.5 of fin area, extending farther between fin rays, dorsal fin base usually 1.1 (1.0–1.3) times length of anal fin base, fins rounded and moderately high, anal fin longer than dorsal fin, middle rays longest; anal fin origin usually under 0.6 (0.4–0.7) distance posteriorly along dorsal fin base. Pelvic fins moderately long, 8.8 (8.0–9.9) in SL, 0.9 of pectoral fin length, usually inserted at, or just posterior to, mid-point of standard length and extending about 0.5 distance to anal fin base; pectoral fin moderately large and paddle-shaped, 8.1 (7.5–9.2) in SL, extending just over 0.4 distance to pelvic fin base, low on body with dorsal end of fin base level with, or slightly above, posterior extent of mouth, lamina of paired fins oriented anterio-ventrally, raised lamellae rarely present, if so, weakly developed on ventral surface of rays, mainly on the distal end of the first few rays. Caudal fin of moderate length, 7.6 (7.0–8.2) in SL, emarginate, equal to, or very slightly longer than, caudal peduncle, vertical width of expanded rays greater than body depth through pectoral fin base, flanges low and well developed along caudal peduncle, reaching anteriorly to just past distal end of adpressed anal fin rays, usually farther, occasionally almost to anal fin base.

Size. Recorded to 110 mm LCF and 12.9 g; commonly to 70–80 mm LCF.

Colour in life. Body predominantly brown on back and upper sides above lateral line, extending onto top and sides of head and snout, and lateral sides of trunk posterior to anal fin, becoming light brown to cream ventrally, belly almost silvery white. Overlain by small to moderate sized dark brown to black, irregular shaped blotches, some coalescing to form irregularly shaped vertical bands; gill cover translucent with small golden patch; wide, diffuse and pale, mid-lateral band of copper flecks, becoming more noticeable on caudal region. Iris silvery gold; fins generally brown, light brown or pale orange. Gravid females with fine black to dark grey stippling along ventro-lateral surface of trunk between the pectoral fin base and vent. See below for more detailed comments on body pattern.

Colour of preserved material. Base colour of head and body light tan to pale creamy brown. Dorsal surface of head and trunk usually with dusky shading composed of very fine brown stippling, darker dorsally and fading down sides but extending onto ventral surface. Irregularly shaped, small and large, brown blotches tending to diffuse bars, reminiscent of flecks, randomly dispersed on dorsal and lateral surfaces, extending down sides to below lateral line, occasional larger, vertical, blotches, centred on lateral line, usually darker brown, contrasting in tone to nearby paler blotches and shading. Dusky shading extending onto head as fine brown stippling, darker on dorsal surfaces, fading down sides and light on ventral surface. Some medium to fine, black or brown spotting inside operculum and dark fine spotting at base and along gill filaments.

Eye grey to black, pupil translucent pale orange-yellow. Teeth translucent pale orange-yellow, tips orange to orange-red; gill rakers pale cream. Fins pale cream to tan, becoming more translucent on posterior margins, finer body pattern and shading extending onto fleshy bases of dorsal, anal and pectoral fins, and onto base of caudal fin. Fin rays translucent, external edges of rays highlighted with very fine black lines, first few rays generally darker.

Etymology. From the Latin aequalis, meaning like or same and pinna, meaning fin, in reference to the almost equal size, on average, of the pectoral and pelvic fins in this species, which are the most equal of all members within the G. olidus complex. Suggested vernacular name as the ‘East Gippsland Galaxias’.

Genetics. Allozyme and mtDNA analysis of this species can be found in Adams et al. (2014; taxon code AR). Diagnostic allozyme loci (4–13) between this taxon and the other species in the Galaxias olidus complex are provided in Table 12.

Distribution. See Fig 7 . Known from the Arte River system, a tributary of the Goolengook River, Bemm River catchment, in the coastal East Gippsland region of Victoria, at an elevational range of 250–> 390 m asl. Recorded downstream in the Arte River to Arte Road near Pikes Hill Track, and from the mid reaches of the Little Arte River, which joins farther downstream, though its distribution in intervening waters is unknown. Therefore, currently known from the headwater section of the Arte River extending 13 km from the source, and from a section of the Little Arte River extending 7 km from the source, with a combined catchment area of 46 km 2 (27 km 2 and 19 km 2 respectively).

Sympatry. Only species in the Galaxias olidus complex found within its range (however, see Remarks, below), although G. brevipinnis and G. maculatus are also known from the Bemm River system.

Habitat. Recorded from small to moderately large (1.5–6.0 m average width and 0.15–0.40 m in average depth), well-shaded and cool, clear to slightly tannin-stained streams, flowing through densely forested catchments, consisting of pools, glides and riffles, with smaller amounts of rapids and backwater areas. Substrate consisted predominantly of bedrock with boulder and cobble, with smaller amounts of gravel and coarse sand, and relatively large areas of silt deposits. Instream cover was provided predominantly by rock, vegetation overhang and timber debris, with smaller areas of aquatic vegetation, and pools averaged 0.6–0.8 m in depth.

Conservation status. Endangered ( DSE 2013).

General Biology. Confined to freshwater and considered not to undertake diadromous migrations. Recorded at a density of 0.10–0.28 fish/m 2 and collected with the native species Shortfinned Eel ( Anguilla australis ), Broadfinned Galaxias ( Galaxias brevipinnis ), East Gippsland Spiny Crayfish ( Euastacus bidawalus ), Gippsland Spiny Crayfish ( Euastacus kershawi ) and Common Freshwater Shrimp ( Paratya australiensis ). The predatory alien species Brown Trout ( Salmo trutta ) is present farther downstream in the Goolengook River system. Spawning period is possibly during winter to spring, but may be variable. Fish collected in late February 2002 (late summer) were at an early stage of gonad development but in late May 1992 (end of autumn) were at an advanced stage, with males running ripe and female gonads well developed and generally in a ripe stage. The majority of fish recorded in late May were> 54 mm LCF, with the smallest sexually developing individual 54.8 mm LCF. Confusingly, three individuals also collected in late May were juveniles (37.0, 39.5 and 41.4 mm LCF respectively), considered of 0+ age, possibly indicating a late spawning with a possible November-December hatching. One individual found to be infected with a short, thin, white worm, coiled and pointed at both ends, from amongst fat deposits around stomach in the body cavity.

Remarks. Raised lamellae on paired fins were infrequently encountered, and were also poorly developed. If present, they were characterised as very short in length along the rays, small thickenings on the distal end of the first few rays of the pectoral fins only, and difficult to distinguish.

Brown Trout have not been recorded from the Arte River system at the above sites, but are abundant in the Goolengook River approximately 4 km downstream from the junction with the Little Arte River, which is 7 km downstream from the collection site for Galaxias aequipinnis in the Arte River, and 4 km downstream from the collection site in the Little Arte River. Their presence in the lower Arte River, and possibly Little Arte River, is strongly suspected, which would limit the current downstream distribution of G. aequipinnis , which is considered to have been historically more widespread, possibly occupying the majority of the Goolengook River system.

Individuals belonging to the Galaxias olidus complex, have been collected from farther north-east in the Bemm River system (NMV A.30646-1 (5), Shady Creek, a tributary of the Errinundra River), though their identity has not been determined due to a lack of suitably preserved specimens. No fresh material was collected during extensive sampling for this study. The available individuals, collected in 1992, are small (<53 mm LCF) but superficially resemble Galaxias aequipinnis , though initial examination has detected some morphological differences between the taxa, and with all other species within the complex in nearby catchments. This suggests the possibility of further undescribed species diversity in the upper Bemm River system and additional survey effort in this area is required to locate material and resolve this issue.

Figures

FIGURE 6. A–B: Galaxias aequipinnis sp. nov. holotype, NMV A.30565-2, 79.8 mm LCF, Arte River, Glen Arte Road, west of Club Terrace, Murrungower State Forest, Victoria, A) line drawing (R. Plant), B) image of preserved specimen (note: distal end of caudal fin is bent to the left in the horizontal plane) (T.A. Raadik); C) Galaxias aequipinnis, collected at the type locality with the holotype, 25 February 2002; ~ 70 mm LCF. (R. Kuiter); D) Arte River, at type locality of Galaxias aequipinnis, facing downstream, 25 February 2002 (T.A. Raadik). Scale bar = 5 mm.

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).