Toothfish Range

Antarctic toothfish are native to the Southern Ocean and have very niche adaptations to be able to thrive in icy, sub-freezing water. These fish generally stay within the Antarctic convergence, which is the area of the ocean directly surrounding Antarctica. Researchers have concluded that Antarctic toothfish form a constant distribution around the continental shelf of Antarctica, but they have also been found more north at 57 degrees south in the Indian Ocean and 62 degrees south in the Atlantic Ocean. Additionally, with capture and release methods, scientists were able to discover their movement and migration patterns. A majority of the recaptured Antarctic toothfish were found to have traveled less than 50 km from their original place of capture, while a much smaller portion of the recaptured fish traveled up to 100 km from their original place of capture.

Contrastingly, another related species of toothfish, the Patagonian toothfish, have a much different range than Antarctic Toothfish. Species distributions of Patagonian toothfish don’t often overlap with those of Antarctic toothfish, as Patagonian toothfish are usually found a bit further north of the continent on the outer sectors of the Antarctic convergence, with a much wider range of distribution extending out to sub-antarctic waters in the Indian, Atlantic, and Pacific Ocean. Unlike the Antarctic toothfish, their Patagonian cousins don’t have anti-freeze in their blood and cannot withstand the freezing waters south of the convergence. While they are most commonly found in the Southern Ocean, one large Patagonian toothfish was found as far north as Greenland! Scientists reported that Patagonian toothfish may sometimes migrate all the way from sub-antarctic waters to sub-arctic waters. It’s predicted that they stay in very deep and cold waters to make this journey.

References:
Hanchet et al. (2015). DOI10.1007/s10750-015-2435-6; https://niwa.co.nz/fisheries/research-projects/antarctic-fisheries-research/the-toothfish;
​Moller et al. (2003). https://www.nature.com/articles/421599a

Photo credits: Paul A. Cziko, Rob Robbins, https://niwa.co.nz/fisheries/research-projects/antarctic-fisheries-research/the-toothfish