Patagonian Toothfish is one of the tastiest fish available on the market, well-known for its firm white flesh, even texture and the abundance of Omega-3 oils in the meat. It is sold under the trade name of Chilean Sea Bass in the USA, Merluza Negra in Chile, Argentina and Uruguay, and Mero in Japan. A close relative, the Antarctic Toothfish (Dissostichus mawsoni) is found further south around the edges of the Antarctic shelf.
Toothfish 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. Distribution ranges from Southern Chile, the Falkland Islands, South Georgia, the sub-Antarctic islands and seamounts of the Indian Ocean sector including the Kerguelen Islands, and Macquarie and Heard Islands.
The fish takes 10 to 12 years to reach breeding age; at this stage they are about 70 cm to 1 metre long. The average weight of a commercially caught toothfish is between 6 to 10 kgs with large adults occasionally exceeding 100 kgs. They are thought to live to around 50 years of age.
Toothfish feed largely on squid and fish and constitute part of the diet of sperm whales, by far their most significant predator.
It was first discovered and exploited commercially in Chile in the late 1980’s leading to its common name of “Chilean Sea Bass”. Nevertheless, it is neither Chilean nor a Sea Bass, but is actually of the Southern Rock Cod family (Nototheniidae).