Galaxias pedderensis
Pedder Galaxias
Species Summary
Galaxias pedderensis came within a hair of becoming the first Australian freshwater fish to be driven to extinction. Endemic to the tributaries of the original Lake Pedder in south-west Tasmania, it was threatened by loss of habitat as well as predation and competition from introduced Brown Trout (Salmo trutta) and the native Climbing Galaxias (Galaxias brevipinnis); as far as is known, it no longer survives anywhere in what remains of its original habitat.
Etymology
The species name uses the place-name suffix -ensis, referring to Lake Pedder and its immediate surrounds in southern Tasmania, where the species is endemic.
Etymology compiled from C. Scharpf (2019), “Fishes of Sahul: An Etymological Survey (Part 2)”, Fishes of Sahul 33(2): 1417–1439, and etyfish.org.
Conservation & Remarks
In 1991–92, in a last-ditch rescue effort, 31 fish were moved to Lake Oberon, a fish-free lake in the Western Arthur Range. The gamble paid off: population surveys by the Inland Fisheries Service and the University of Tasmania in January 2001 found at least 500 adult Pedder Galaxias established at Lake Oberon, along with large numbers of pelagic juveniles. To spread the risk further, 52 adults from this new population were moved again in March 2001, this time to a fish-free dam near Strathgordon that Hydro Tasmania and the Inland Fisheries Service had specially modified for the species, with a weir-fed inflow stream and barriers to stop other fish invading via the outflow. Night-time snorkel surveys in September 2003 confirmed at least eight healthy fish surviving in the Strathgordon dam, all found in the inflow stream in a pattern that hinted at spawning preparations, though a follow-up larval survey that December found none yet.
Along with the Swan Galaxias and the Clarence Galaxias, the Pedder Galaxias is one of three Tasmanian galaxiids so vulnerable to introduced trout that all three now survive only in trout-free waters. The fragility of that arrangement was underlined in the early 2000s when illegally introduced rainbow trout were discovered in Johnsons Lagoon, a World Heritage Area wetland holding one of only seven remaining populations of the Clarence Galaxias at the time — a reminder that even well-protected relict populations remain one bucket of illegally released fish away from disaster.
Compiled for Home of the Rainbowfish from ANGFA sources: “Pedder Galaxias on the move!”, In-Stream 11(4), August/September 2002, p. 23; and J. Jackson, “Translocated Pedder galaxias at Strathgordon”, In-Stream 12(5), October 2003, p. 18.