Thunnus maccoyii
Thunnus maccoyii

Distribution

Temperate Australasia, Temperate South America


Description

Open water species that occurs in large schools in subtropical and temperate waters. Two other tunas also commonly occur in the region, the albacore Thunnus alalunga, a species with very long pectoral fins extending back behind the second dorsal fin, and the yellowfin tuna T. albacares, a species with yellow dorsal and anal fins. The southern bluefin tuna spawns in the Indian Ocean off northwestern Australia, with juvenile fish migrating down the western and then along the southern coasts, gaining in size as they travel. Heavy fishing along this migratory route during the past four decades has reduced stocks to a small fraction of former levels.


Information

Max Size: N/A cm

Sea Temperature Range: N/A

Depth: N/A

Habitat Generalization Index: N/A

Also referred to as the SGI (Species Generalisation Index), this describes the habitat niche breadth of the species. Species with values less than 15 are found in a relatively narrow range of reef habitat types (specialists), while those over 25 may be found on most hard substrates within their range (generalists). Learn more here.


Conservation and Rarity

IUCN Status: Vulnerable

Occurrence: Rare (0.8% of sites)

Occurrence describes how often the species is found on surveys within its distribution. It is calculated as the % of reef sites surveyed by RLS divers across all the ecoregions in which the species has been observed

Abundance: Several (9 per transect)

Abundance is calculated as the average number of individuals recorded per RLS transect, where present.


Edit by: GJ Edgar. 2008. Australian Marine Life. New Holland, Sydney