Marjorie's hardyhead (Craterocephalus marjoriae) fish species and information / pictures of Marjorie's hardyhead - Craterocephalus marjoriae

Marjorie's hardyhead (Craterocephalus marjoriae) fish species information

Scientific Name
Craterocephalus marjoriae

Common Name
Marjorie's hardyhead

Biology
Distinguished from Craterocephalus marianae and Craterocephalus munroi and all other members of the genus by a combination of the following: head 3.0-3.4 (3.1); greatest body depth 3.6-4.7 (4.1); least body depth 8.8-11.0 00.0); origin of pectoral fin to anus 2.7-3.1 (2.9), all in SL. Dorsal process of premaxilla 1.1-1.70.4 in eye. Midlateral scale count 28-30 (29.1); transverse scale count 5.5-6.5 (6.0); vertebral count 30-32 (31.4). Position of anus in relation to tip of pelvic fin from 0.5 scales in front to 2 scales behind tip of pelvic fin. Differs osteologically from all other Craterocephalus species by a combination of the following: shape of anterior medial process of maxilla; lack of interdorsal pterygiophores (but shared with some other members of C. eyresii group); minute anterior process usually present on cleithrum; dorsal process of cleithrum also present; basisphenoid short and thick. Differs genetically from Craterocephalus marianae at the following loci: ADA, CK, FDP,

Classification

Classified By
Whitley, 1948
Class
Ray-finned fishes (Actinopterygii)
Order
Silversides (Atheriniformes)
Family
Silversides (Atherinidae)

Distribution

Region
Oceania
Distribution
Oceania: endemic to Australia.
Range
Unknown

Environment

Climate
Tropical
Water Temperature From
24 °C
Water Temperature To
30 °C
Depth From - meters
Unknown m
Depth To - meters
Unknown m
Zone
benthopelagic
Environment
Freshwater; benthopelagic
Trophic Level
2.93 s.e. 0.36 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
8.5 cm
Common Length
5.0 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
Unknown
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
  Not Evaluated