Craterocephalus dalhousiensis Ivantsoff & Glover, 1974
Dalhousie hardyhead

Family:  Atherinidae (Silversides), subfamily: Craterocephalinae
Max. size:  8 cm TL (male/unsexed)
Environment:  benthopelagic; freshwater
Distribution:  Oceania: restricted to the Dalhousie Springs, South Australia.
Diagnosis:   
Biology:  Inhabits warm water artesian springs and their outlet streams (Ref. 2906, 44894). Tolerates temperatures ranging from 20°-39°C, but has been recorded briefly entering water of 41.8°C to feed. A diurnally-active species which has one of the highest recorded voluntary temperature tolerances of any fish species in the world (Ref. 44894). Feeds on gastropods, aquatic plants (Ref. 2906), green filamentous algae, detritus and small invertebrates which are taken from the bottom (Ref. 44894). Dimorphic: bigger females with concave head and flat belly, long cylindrical sac-like ovary on left side of fish while the yellow-white testis lies on the right side. Appears to suffer thermal stress above 38°C but can tolerate low oxygen levels (Ref. 7276).
IUCN Red List Status: Critically Endangered (CR); Date assessed: 07 February 2019 (B1ab(i,ii,iii,iv)) Ref. (130435)
Threat to humans:  harmless
Country info:   
 


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