R. Wager and P. Jackson
Environment Australia, June 1993
ISBN 0 6421 6818 0
Species recovery outline: Saddled Galaxias
Scientific name: Galaxias tanycephalus
English name: Saddled Galaxias
Species taxonomic status: Formally described by Fulton, 1978. Closely related to the golden galaxias (Galaxias auratus) which occurs in the drainage system adjacent to the habitat of the Saddled Galaxias.
Species survival status: Two populations known but only one sufficiently large to guarantee long term survival.
- Action plan status: Vulnerable.
- Australian Society for Fish Biology status: Vulnerable.
- Proposed new IUCN criteria status: Vulnerable (possibly N< 10 000 and > 1% annual decline over past 10 years).
Former distribution: The Saddled Galaxias has only been collected in the vicinity of Arthurs Lake and Woods Lake, on the central plateau of Tasmania.
Current distribution: As above but the Saddled Galaxias is more abundant in Woods Lake than Arthurs Lake.
Although not well documented the differences in population sizes in the two lakes may be due to two key environmental factors:
- Woods Lake is more turbid and chemically concentrated than Arthurs Lake and supports a large crop of phytoplankton (hence zooplankton). Woods Lake probably has the potential to support a larger population of planktivorous larvae.
- Although brown trout are abundant in both lakes, Arthurs Lake holds a larger population. Combined with the increased water clarity, predation by brown trout is probably exacerbated in Arthurs Lake.
Habitat: Usually found amongst rocks along the margins of the lakes. Larval stages are pelagic.
Reasons for decline:
- Abundance is possibly limited through predation by brown trout.
- A water diversion scheme adding nutrient rich water to Woods Lake may be a potential threat.
Conservation reserves on which species occurs: None known.
Other public lands on which species occurs: Hydro-Electric Commission land.
Other land on which species occurs: Private grazing land.
Is knowledge about species adequate for objectives and actions to be defined accurately? (If not provide list of additional studies required): Yes.
- Maintain current populations and distribution.
- Investigate suitable sites for translocation.
- Monitor abundance in both lakes.
- Identify factors responsible for limiting the populations in both lakes.
- Monitor the effects of changing land use patterns around Woods Lake.
- Establishment of additional breeding populations.
Management actions already initiated:
- No natural sites suitable for translocation could be found.
- Effects of changing land use patterns are being investigated.
Management actions required:
- Declaration of additional conservation reserves: Not required.
- Habitat management: Yes. Management of nutrient input into the lakes may be required.
- Feral animal control: Yes. The brown trout population in Woods Lake should not be artificially enhanced, either by stocking or by increased spawning facilities. Natural processes which may limit trout reproduction (log jams or low water levels) should be allowed to occur.
- Translocation or re-establishment of populations: Yes. The possibility of establishing additional populations in artificial environments (farm dams) should be investigated.
- Captive breeding: Not required.
- Other: No.
Organisations responsible for conservation of species:
- Inland Fisheries Commission.
Other organisations or individuals involved:
- Department of Environment and Land Management.
Can recovery plan be carried out with existing resources?: No.
- Cost of annual monitoring of this species would be included in an annual program to monitor Swan Galaxias, Clarence Galaxias, swamp galaxias, Saddled Galaxias and Dwarf Galaxias (see Swan Galaxias for details). Annual funding required for monitoring of this species would be $2 440.
Annual monitoring $2 440
Remarks: If monitoring program shows that populations are decreasing the causal factors should be investigated.