Dalhousie hardyhead (Craterocephalus dalhousiensis) fish species and information / pictures of Dalhousie hardyhead - Craterocephalus dalhousiensis

Dalhousie hardyhead (Craterocephalus dalhousiensis) fish species information

Scientific Name
Craterocephalus dalhousiensis

Common Name
Dalhousie hardyhead

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).

Classification

Classified By
Ivantsoff & Glover, 1974
Class
Ray-finned fishes (Actinopterygii)
Order
Silversides (Atheriniformes)
Family
Silversides (Atherinidae)

Distribution

Region
Oceania
Distribution
Oceania: restricted to the Dalhousie Springs, South Australia.
Range
26°S - 27°S

Environment

Climate
Tropical
Water Temperature From
Unknown °C
Water Temperature To
Unknown °C
Depth From - meters
Unknown m
Depth To - meters
Unknown m
Zone
benthopelagic
Environment
Freshwater; benthopelagic
Trophic Level
2.71 s.e. 0.40 Based on food items.
Occurs in Marine / Salt water
False
Occurs in Brackish water
False
Occurs in Fresh Water
True
Occurs on Reefs
False
Is kept in Aquariums
False

Physical Size and Genetics

Maximum Length
8.0 cm
Common Length
Unknown cm
Phylogenetic Diversity Index
PD50 = 0.5000 many relatives (e.g. carps) 0.5 - 2.0 few relatives (e.g. lungfishes)

Human Uses and Population

Human Uses
Fisheries: of no interest
Vulnerability
Low vulnerability (18 of 100)
Resilience
High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.)
Threat To Humans
  Harmless
IUCN Red List Status
  Vulnerable (VU) (D2)