Lake Eyre Hardyhead, Craterocephalus eyresii (Steindachner 1883)


Other Names: Central Australian Hardyhead, Desert Hardyhead

Lake Eyre Hardyhead, Craterocephalus eyresii. Source: Neil Armstrong. License: All rights reserved

Summary:
A drab yellowish-grey hardyhead becoming greenish-silvery below the silver mid-lateral stripe, dark melanophores around the mid-lateral line, and transparent to yellowish fins.
Lake Eyre Hardyheads have the highest and widest salinity tolerance range of any Australian fish species, and occur in waters ranging from purely fresh to salinities of 110 ppt. They inhabit temporary water bodies in the Lake Eyre basin, South Australia and appear to persist by moving between semi-permanent waterholes. 
Video of Lake Eyre Hardyheads in Willochra Creek, South Australia.

Cite this page as:
Thompson, V.J. & Bray, D.J. 2018, Craterocephalus eyresii in Fishes of Australia, accessed 29 Jan 2020, http://136.154.202.208/home/species/4634

Lake Eyre Hardyhead, Craterocephalus eyresii (Steindachner 1883)

More Info


Distribution

Known only from the Lake Eyre drainage basin, South Australia. Occurs in Lake Eyre and rivers to the south and west of it. Also found in Lake Frome and its tributaries in the Northern Flinders Ranges and Lake Torrens and its tributaries. Inhabiting temperate ephemeral rivers, streams, natural springs, salt-lakes and human-made bores, usually over gravelly substrates around submered vegetation. Occurs in a wide range of salinities from pure freshwater to highly saline water (110 ppt).

Features

Dorsal fin IV-VII + I, 5-7; Anal fin I, 5-8; Pectoral fin 12-14; Gill rakers 11-12; Vertebrae 32-37

Body laterally compressed, relatively elongate; maximum body depth 3.8-5.3 in SL; body depth increases with age with head sloping more towards the snout; head and eyes of moderate size; mouth protractile; lips moderately fleshy; gape restricted by fusion of lips from about half to two thirds way along premaxilla; jaw teeth small.

Scales moderately small, strong, not always in even rows above or below midlateral stripe; circuli obvious on all scales; scales on dorsum of head irregular, usually larger than body scales; opercles with scales; horizontal scale rows 11-14; vertical scale rows 30-34.

Two widely separated dorsal fins; 1st dorsal fin originates before tips of ventral fins; anal fin origin below origin of second dorsal fin; dorsal caudal fin forked;

Size

Maximum 9.6 cm SL, commonly 6-7 cm

Colour

Yellowish grey overall with a silver mid-lateral stripe and greenish-silvery ventrally with dark melanophores around the mid-lateral line. Fins clear to yellowish.

Feeding

Omnivorous, feeding on small invertebrates, particularly microcrustaceans, and algae.

Biology

Breeding season from January to March but breeds opportunistically during flooding; pair spawners with females depositing adhesive eggs amongst aquatic vegetation. Eggs large, 1mm diameter at greatest development

Fisheries

No existing fishery

Conservation

Not listed on the IUCN Red List of Threatened Species.
Not listed under the Australian EPBC act.

Remarks

Refuge areas allow sufficient numbers to survive dry seasons allowing dispersal and rapid breeding to occur in favourable conditions. Increasing salinity and water evaporation may then again lead to deaths from these areas.

Similar Species

Crowley and Ivantsoff (1990) revised the Lake Eyre hardyhead classification and split it into four species, Darling River hardyhead (C. amniculus), Finke hardyhead (C. centralis), Lake Eyre hardyhead (C. eyresii), and Murray hardyhead (C. fluviatilis). C. eyresii is superficially most similar to C. fluviatilis but differs from this and all other species in the genus in horizontal scale row counts and body depth.

Etymology

Generic name Craterocephalus comes from the Greek meaning bowl or basin and head, possibly in reference to the strong head of species in this genus. Species name is derived from the type locality, Lake Eyre.

Species Citation

Atherinichthys eyresii Steindachner 1883, Anzeiger der Akademie der Wissenschaften in Wien 20(22): 194. Original type locality: Emerald Spring, Northern Territory (original type lost). Neotype locality: Strangeways Springs, Northern Territory.

Author

Thompson, V.J. & Bray, D.J. 2018

Lake Eyre Hardyhead, Craterocephalus eyresii (Steindachner 1883)

References


Allen, G.R. (1989). Freshwater Fishes of Australia.  Neptune, New Jersey : T.F.H. Publications pp. 1–240

Allen, G.R., Midgley, S.H. & Allen, M. (2002). Field guide to the freshwater fishes of Australia.  Perth : Western Australian Museum 394 pp.

Crowley, L.E.L.M. & Ivantsoff, W. (1990). A review of species previously identified as Craterocephalus eyresii (Pisces: Atherinidae). Proc. Linn Soc. N.S.W. 112(2): 87–103

Glover, C. J. M., & Sim, T. C. (1978). Studies on central Australian fishes: a progress report. South Australian Naturalist. 52(3): 35-44.

Larson, H.K. & Martin, K.C. (1990). Freshwater Fishes of the Northern Territory. Northern Territory Museum of Arts and Sciences Handbook Series Number 1.  Darwin : Northern Territory Museum of Arts and Sciences 102 pp.

McDowall, R.M. (ed.) (1980). Freshwater Fishes of South-eastern Australia.  Sydney : A.H. & A.W. Reed 208 pp.

Merrick, J.R. & Schmida, G.E. (1984). Australian Freshwater Fishes Biology and Management.  Sydney : J.R. Merrick 409 pp.

Ruello, N. V. (1976). Observations on some fish kills in Lake Eyre. Australian Journal of Freshwater and Marine Research. 27: 667-672.

Steindachner, F. 1883, Ichthyologische Beiträge (XIII). Anzeiger der Akademie der Wissenschaften in Wien 20 (22): 194-197.

Wager, R. & Unmack, P.J. (2000). Fishes of the Lake eyre catchment of central Australia.  Department of Primary Industries Queensland Fisheries Service 88 pp.

Quick Facts


CAAB Code:37246019

Habitat:freshwater

Max Size:9.6 cm

Native:endemic

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