Scientific Name
Craterocephalus helenae

Common Name
Drysdale hardyhead

Biology
Found in rocky pools in clear, flowing streams. Occurs in still or flowing water of sandy river channels and rocky pools (Ref. 44894). Feeds chiefly on insects and their aquatic larvae and crustaceans, but some algae is also consumed.

Classification

Classified By

Ivantsoff, Crowley & Allen, 1987

Class

Ray-finned fishes (Actinopterygii)

Order

Silversides (Atheriniformes)

Family

Silversides (Atherinidae)

Distribution

Region

Oceania

Distribution

Oceania: known only from the Drysdale River in the northern Kimberley region, Western Australia.

Range

15°S - 16°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

3.02 s.e. 0.37 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

5.5 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 (23 of 100)

Resilience

High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.)

Threat To Humans

Harmless

IUCN Red List Status

Lower Risk: near threatened (LR/nt)