R. Wager and P. Jackson
Environment Australia, June 1993
ISBN 0 6421 6818 0
Species recovery outline: Murray Hardyhead
Scientific name: Craterocephalus fluviatilis
English Name: Murray Hardyhead
Species taxonomic status: Formally described by McCulloch, 1913. Identified by Ivantsoff et al. 1987 as a junior synonym of Craterocephalus eyresii but recent work (Crowley and Ivantsoff, 1990) has shown this identification to be incorrect.
Species survival status: Suspected to have experienced major reduction in distribution.
- Action plan status: Vulnerable.
- Australian Society for Fish Biology status: Potentially Threatened.
- Proposed new IUCN criteria status: Vulnerable (possibly habitat modification and interaction with introduced species).
Former distribution: Uncertain due to lack of records. Thought to be widespread in the Murray-Darling Drainage Basin, but probably absent from the Darling River and tributaries.
Current distribution: Appears to be restricted to the Kerang Lakes area (Victoria) and possibly the nearby Murray River. This is not certain. Specimens were recorded from the lower Murray River in 1986.
Habitat: Margins of slow, lowland rivers and in lakes, billabongs and backwaters. Found amongst aquatic plants and over gravel beds in both fresh and highly saline waters.
Reasons for decline: Unknown. Comments for decline of fish generally probably apply.
Conservation reserves on which species occurs: None.
Other public lands on which species occurs: Recorded from the following sites in the last 10 years:
- Elizabeth Lake Water Supply Reserve;
- Small portion of Water Reserve and unreserved public land at Lake Hawthorn.
Other land on which species occurs: Recorded from the following sites in the last 10 years:
- Private golf course lake.
- Private land along Murray River.
Is knowledge about species adequate for objectives and actions to be defined accurately? (If not provide list of additional studies required): No.
- Need to determine precise distribution and abundance.
- Need information on ecological requirements.
- Determine reasons for decline.
- Protect known populations and habitat.
- Locate and protect any other populations.
- Investigate potential sites for translocation and establish new populations if required.
Management actions already initiated: None known.
Management actions required:
- Declaration of additional conservation reserves: Yes. At least for the major population at Kerang Lakes.
- Habitat management: Possibly required pending results of ecological determinations.
- Feral animal control: Possible control of redfin if thought to be a threat through predation.
- Translocation or re-establishment of populations:
- Possibly required; only if suitable location is found.
- Captive breeding: Yes. Probably breeds like other hardyheads. Captive populations should be established.
- Other: No.
Organisations responsible for conservation of species:
- Victorian Department of Conservation and Natural Resources.
- Department of Agriculture and Fisheries, New South Wales.
- Department of Fisheries, South Australia.
Other organisations or individuals involved:
- Walter Ivantsoff.
- Native Fish Australia.
Can recovery plan be carried out with existing resources?: No.
- A two year co-operative project between New South Wales, Victoria and South Australia needs to be initiated to investigate the species and evaluate possible protection measures. One biologist and one technician would be required – $147 000, plus operating funds of $30 000 each year.
- 19.2 Captive populations could be maintained by members of the Australia New Guinea Association or Native Fish Australia. Labour would probably be voluntary, but necessary equipment would need to be provided – $5 000.
Total: $212 000
- Recent changes to the taxonomy have caused confusion concerning the status of this species. Details on localities and populations are uncertain.