Lake Eyre

Lake Eyre hardyhead Fish

Taxonomy

Crowley and Ivantsoff (1990) recently revised the Lake Eyre hardyhead and split it into four species, Darling River hardyhead (C. amniclus), Finke hardyhead (C. centralis), Lake Eyre hardyhead (C. eyresii), and Murray hardyhead (C. fluviatilis). Most previously published information on Lake Eyre hardyhead was obtained from, and is now largely applicable only to Murray hardyhead.

Size

To 100mm (4in) TL.

Conservation Status

None.

Distribution & Abundance

Three isolated populations exist; Lake Eyre and the rivers to the south and west of it; Lake Frome and its tributaries in the Northern Flinders Ranges; and Lake Torrens and it's tributaries (which is not a central Australian drainage). They may occasionally be found in the lower reaches of most rivers draining into Lake Eyre, ie Cooper Creek and Diamantina River; however, these are probably only ephemeral populations. Their abundance and distribution fluctuates widely. In fact, most of the places they occur have no permanent water, they appear to persist by leapfrogging between semipermanent waterholes.

Habitat & Ecology

They have been collected from a variety of different habitats including large ephemeral lakes*, major rivers and their associated waterholes, minor streams, springs, flowing bore (well) drains, and small human constructed reservoirs and dams. Lake Eyre hardyhead populations fluctuate to the extreme, it was estimated that at least twenty million died as salinity levels rose in Lake Eyre with falling water levels in 1975 prior to it drying up after record floods (Ruello 1976). They have the highest and widest salinity tolerance of any Australian fish, 0-110 ppt (Glover & Sim 1978).

*An ephemeral waterbody is a wetland, spring, stream, river, pond or lake that only exists for a short period following precipitation or snowmelt. They are not the same as intermittent or seasonal waterbodies, which exist for longer periods, but not all year round.

Reproduction

Their breeding biology is probably similar to Murray hardyheads and other craterocephalids. No specific studies have been undertaken.

Threats

None specifically.

Conservation Action

None.

See Also

• Lake Eyre Summary
• Lake Eyre Geography
• Lake Eyre Floods
• Lake Eyre Yacht Club
• Lake Eyre Fauna
• Lake Eyre Wildlife