A relatively large galaxiid with a large, dorsoventrally flattened head and a large mouth reaching to below the eyes. Maximum size 278 mm; usually 150–180 mm. Adults are sturdy and almost tubular, and usually have a blue-black blotch above the base of the pectoral fins. The tail is truncate, and the pectoral and pelvic fins are very large, low and downward facing, hence its alternative common name of Broad-finned galaxias. The origin of the anal fin is set back from the origin of the dorsal fin.
The body is scaleless and greyish brown to olive, often patterned with bold chevron stripes on the dorsal and lateral surfaces, and the belly is a dull silvery olive.
The Climbing galaxias is normally a fish of coastal streams, but it has been transferred to the upper Murray drainage in water from the Snowy River, via the Snowy Mountains Scheme. It gets its common name from its ability to climb vertical wet surfaces such as waterfalls and instream barriers, though species in the Mountain galaxias complex are also known to climb. It does this by utilising surface tension, maximised by pressing its large pectoral and pelvic fins (with backwards-facing ridges) against wet rocky surfaces to wriggle forward in shallow or exposed margins of barriers.
It is among the several coastal galaxiids that can survive and reproduce as landlocked populations. In coastal streams it breeds during autumn and winter, scattering its eggs amongst vegetation on the stream edge above the normal flow level, presumably when streams are in flood. In these sea-run populations the eggs are deposited in flooded riparian areas, usually within 1 m but up to 7 m from the water’s edge. Fecundity is high: up to 23,676 eggs have been reported, and an average of 7,000 per individual.
The eggs are round, adhesive and 1.8–2.1 mm diameter. Landlocked populations in New Zealand have been found to have different reproductive strategies than coastal fish with a more protracted spawning season (late winter to early summer), smaller egg size, and higher fecundity.
They develop out of water in these damp habitats for days or weeks and hatch with the next flood. The larvae are swept downstream to marine habitats, where they remain for 4–6 months before migrating back (as 40–50mm long ‘whitebait’) into estuarine and freshwater habitats.
The reproductive ecology in the landlocked populations of the Basin is unknown, but in similar situations in Tasmania large lakes replace the marine larval stage. There has been little investigation into the species’ ecology in the MDB but in the upper Murray spawning is thought to occur in late April or early May. In coastal populations in Vic, elevated flows increase the abundance of juveniles returning from marine environments.
The diet consists mainly of aquatic invertebrates such as mayflies, caddisflies, dipterans and small crustaceans. The species is renowned for its ability to climb vertical waterfalls and rock faces, using its broad pectoral and pelvic fins.
This widespread species is found in coastal streams of south-eastern Australia and New Zealand, though ongoing recent taxonomic work suggests Australian populations are a different species to those in NZ (Raadik pers. comm.). Although it can be predominantly considered as occurring in the Basin as a result of translocation, a historical record along with recent detection (2013) in the Finniss River (Mt Lofty Ranges) show that it is found naturally in the Lower Murray in SA. It is common in adjoining SA coastal drainages (southern Fleurieu Peninsula and Adelaide Hills).
In the MDB, it is largely restricted to the upper Murray and its tributaries such as the Kiewa, Mitta Mitta, Geehi, Swampy Plains, and Tooma rivers, along with the lower Goulburn and Broken rivers in Vic. A 2002 record of the species from the Tumut catchment (presumably via the Snowy Mountains Scheme) was the first record for the Murrumbidgee drainage, but it is now well established in some streams in the Blowering/ Talbingo area.
A total of 33 individuals were sampled in the Sustainable Rivers Audit from 2004-2013, with most of these records (21) coming from the upper Murray. In the MDB Fish survey (2014/15–2021/22) a total of 71 individuals were recorded (2 from the Broken; 69 from upper Murray catchments).
Where it is a translocated species, the Climbing galaxias may pose a threat to other native fish species, such as galaxiids or blackfish, through competition for food or space and predation.
The Snowy 2.0 pumped hydro scheme has the potential to introduce this species to the upper Murrumbidgee catchment where it will likely compete with and prey upon the critically endangered Stocky galaxias. In its natural habitats, it is threatened by predation and displacement by introduced trout species, and habitat loss through deforestation.
Amtstaetter et al. 2021; Augspurger & Closs 2019; Glova & Sagar 1989; Hale et al. 2008; Hammer 2004; Lintermans 2019; Lintermans et al. 2021; McDowall & Fulton 1996; Merrick & Schmida 1984; Morison & Anderson 1991; O’Connor & Koehn 1998; Raadik 2003, 2008b, 2014; Raadik et al. 2019; Waters et al. 2002; Whiterod et al. 2015; M. Lintermans unpubl. data.
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