Toothfish
Dissostichus eleginoides
Patagonian Toothfish
Patagonian Toothfish (Dissostichus eleginoides) is a deep-sea, demersal species found in the cold, temperate waters of the Southern Oceans.
Young, immature fish are found in shallower waters but as they mature they migrate into deeper waters up to 3,000 metres in depth.
Source: CCAMLR
Locations
Distribution ranges from Southern Chile, the Falkland Islands and South Georgia to the sub-Antarctic islands and seamounts of the Indian Ocean including the Kerguelen, Crozet and Marion Islands, and the Australian Islands of Heard & McDonald.
Toothfish inhabits cold waters between 1°C and 4 °C up to depths of 3,500m. In the Falklands, average fishing depths are around 1,350m, with fishing regularly occurring up to depths of 1,800m.
A Close Relative
The Antarctic toothfish (Dissostichus mawsoni), inhabits Antarctic waters and mainly caught in the Ross Sea during the austral summer, but can be found in many pockets around Antarctic coastal waters.
Source: NIWA
Lifecycle
Toothfish can live up to 50+ years of age and can grow to over 2m in length. Sexual maturity is reached when it is around 70cm to 95cm which equates to between 6 and 10 years of age and has relatively low fecundity. Individuals have been caught with a whole weight exceeding 150 kgs although these larger animals are quite rare.
Toothfish spawn in deep waters during the winter, producing larvae which float to the surface and migrate towards shallower waters of less than 300m where they remain for their juvenile period. As they grow they gradually migrate towards deeper waters as they approach breeding age.
Diet
In the Falkland Islands toothfish feed largely on loligo (squid) and rock cod in their juvenile years, with hakes, skates and deep-sea crustaceans becoming more typical in their diet as they migrate to deeper waters. Once settled at depths of over 1000 m, they typically become opportunistic predators, taking less active and relatively small species. In turn, they constitute part of the diet of sperm whales which are, by far, their most significant predator.
Discovery
It was first discovered and exploited commercially in Chile in the late 1980s leading to its common name of “Chilean Seabass”. The history of its discovery is told by G. Bruce Knecht in his book “Hooked” which…
... chronicles how an obscure fish merchant in California ‘discovered’ and renamed the fish, kicking off a worldwide craze for a fish no one had ever heard of and everyone had to have.
In early years the principle market was Japan where buyers were looking for an alternative to sablefish (a.k.a black cod) which was in decline at the time, but it soon found a market in the USA where it has remained strong since.
