PORT PHILLIP BAY


Southern Bluefin Tuna 

Thunnus maccoyii (Castelnau, 1872)

View scientific description and taxonomy

Scientific Details

Meristics.
Dorsal fin spines/rays: XII-XIV; 14-15; 8-9 finlets
Anal fin spines/rays: 14-15; 7-8 finlets
Caudal fin rays: 17
Pectoral fin rays: 28-34
Ventral fin spines/rays: I, 5
Lateral line: 207-235
Gill rakers: 31-43

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. & Kuiter, R.H. (eds) (2008) Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.

Order level detail.
A large and highly diverse group of modern bony fishes many of which have a generalized perch like body form. Most have pelvic fins with one spine and 5 rays and the maxillary bone is excluded from the gape of the mouth. Interrelationships of the group are poorly understood and continue to be studied. They inhabit almost all aquatic habitats from high-altitude strams to the deep sea, although most are marine.

Family level detail.
Powerful streamlined fishes with two dorsal fins that fold into grooves, deeply forked or lunate tails and a series of dorsal and anal finlets before the narrow tail base. They are fast-swimming open-water predators and are extremely commercially and recreationally important.

Taxonomy

Phylum:
Chordata
Subphylum:
Craniata
Superclass:
Gnathostomata
Class:
Actinopterygii
Order:
Perciformes
Family:
Scombridae
Genus:
Thunnus
Species:
maccoyii

General Description

Body fusiform, of moderate depth, stout, tapering abruptly to a narrow tail base with keels on each side; two dorsal fins close together; anal fin similar to and opposite second dorsal fin; tail lunate; pectoral fins short. Dark blue above, silvery below; caudal keels yellow, although often absent in larger adults; second dorsal fin, caudal fin and finlets also tinged with yellow. To 1.9 m.

Biology

This pelagic migrates along the southern coast and forms a very important fishery in offshore waters.

Habitat

In subtropical and temperate open waters.

Open water

Distribution guide

Southern Indian, Pacific and Atlantic Oceans. Around most of Australia.

Species Group

Fishes › Mackerels and tunas

Depth

Shallow (1-30 m)

Water Column

Midwater Surface

Max Size

1.9 m

Diet

Carnivore

Commercial Species

Yes

Global Dispersal

Recorded in Australia

Conservation Status

  • DSE Advisory List : Not listed
  • EPBC Act 1999 : Conservation Dependent
  • IUCN Red List : Critically Endangered

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, Southern Bluefin Tuna, Thunnus maccoyii, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 25 Feb 2025, http://136.154.202.208:8098/species/6472

Text: creative commons cc by licence