PORT PHILLIP BAY


Ornate Cowfish 

Aracana ornata (Gray, 1838)

View scientific description and taxonomy

Scientific Details

Meristics.
Dorsal fin spines/rays: 10-11
Anal fin spines/rays: 10
Caudal fin rays: 11
Pectoral fin rays: 10

Interpreting fin count meristics.
Spines are in Roman numerals and soft rays are in Arabic numerals. Spines and rays that are continuous in one fin are separated by a comma. Fin sections are separated by semicolons.

Detailed descriptions of fin count and other meristics are in:
Gomon, M.F., Bray, D.J. and Kuiter, R.H. (2008) Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.

Order level detail.
The Tetraodontiformes is a very diverse and specialized group of bony fishes that share the loss, reduction or fusion of many bony structures in the head and body. Fins and their supporting elements are reduced or lost, and vertebrae are reduced in number. They have small mouths with modified teeth that may be enlarged or fused into a beak-like structure, or incorporated into the jaw bones. The gill opening is reduced to a small slit near the pectoral-fin base, and most have thick skin, covered in scales that are modified into spines, ossicles or fused bony plates. Some groups are poisonous, and the puffers and porcupinefishes are highly inflatable. Puffers and their allies are found worldwide in temperate and tropical seas, and a few species enter freshwaters.

Family level detail.
A small family of oval to round fishes with a protective outer covering or carapace, comprised of large fused bony plates. The rigid plates end before or on the tail base which is never completely enclosed in fused plates. The carapace has a series of longitudinal ridges, and bear large fixed spines in some species. All have very small mouths and often locate their invertebrate prey by blowing a jet of water onto the sediment. They lack fin spines and pelvic fins, and the short-based dorsal and anal fins are set far back on the body.

Taxonomy

Phylum:
Chordata
Subphylum:
Craniata
Superclass:
Gnathostomata
Class:
Actinopterygii
Order:
Tetraodontiformes
Family:
Aracanidae
Genus:
Aracana
Species:
ornata

General Description

Body encased in a rigid box-like carapace comprised of large sculptured bony plates, with large recurved spines on bony ridges; dorsal and anal fins opposite and far back on the body; bony plates on tail base absent or rudimentary; lines on snout diagonal. Males with distinct hump on snout and with orange and blue caudal fin. Female dark brown with white or yellowish-white stripes and wavy lines, lines frequently circular dorsally, yellow to bright orange below. To 15 cm.

Biology

This species is quite abundant, especially in very shallow water. It feeds on benthic invertebrates.

Habitat

Shallow seagrass beds in sheltered bays and harbours, and along the coast in depths of 0-15 m.

Seagrass meadows

Distribution guide

Southern Australia.

Species Group

Fishes Cowfishes

Depth

Shallow (1-30 m)

Water Column

On or near sea floor

Max Size

15 cm

Commercial Species

No

Global Dispersal

Native to Australia

Conservation Status

  • DSE Advisory List : Not listed
  • EPBC Act 1999 : Not listed
  • IUCN Red List : Not listed

Author

article author Bray, D.J.

Di Bray is a Senior Collection Manager of ichthyology at Museum Victoria.

Author

article author Gomon, M.F.

Dr. Martin Gomon is a Senior Curator of ichthyology at Museum Victoria.

citation

Cite this page as:
Bray, D.J. & Gomon, M.F., 2011, Ornate Cowfish, Aracana ornata, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 18 Oct 2017, http://portphillipmarinelife.net.au:8098/species/7980

Text: creative commons cc by licence