There are three main species of bluefin tuna that share a number of behavioral strategies, but ultimately have their own unique characteristics that differentiate them from one another.
Explore the differences between the three main bluefin tuna species using this chart.
A closer look at the exploratory chart
Atlantic Bluefin Tuna
A photograph of an Atlantic Bluefin Tuna (National Oceanic & Atmospheric Administration Fisheries, n.d.)
Atlantic bluefin tuna (Thunnus thynnus) are the largest of the three bluefin tuna species (American Oceans, n.d.). This makes them particularly attractive catch for fishermen in the Mediterranean and Gulf of Mexico, and has ultimately led to their designation as an endangered species.
While each tuna can lay upwards of 500 million eggs in a single spawning season, the Atlantic bluefin tuna population is less than half of what it was in 1974 as they are often caught before their age of maturation of 8 years old (Nikolic, 2021).
These fish are known to be highly migratory predators. They are often compared to sharks due to their fast swimming speeds and counter-current heat exchange system (University of Michigan Museum of Zoology, n.d., a). However, unlike sharks, Atlantic bluefin tuna prefer to swallow their prey whole.
Pacific Bluefin Tuna
A photograph of a Pacific Bluefin Tuna (National Oceanic & Atmospheric Administration Fisheries, n.d.)
Pacific bluefin tuna (Thunnus orientalis) swim in the temperate waters of the northern Pacific, but may find themselves travelling to the southern tropics during the winter (University of Michigan Museum of Zoology, n.d., b).
Unlike their Atlantic counterparts, Pacific bluefin tuna are members of a single stock. That is to say that they have a single spawning site north of the Philippines wherein each tuna lays approximately 15 million eggs per season (Nikolic, 2021).
The Pacific bluefin tuna are the fastest and most expensive of the three species with one fish selling for nearly 2 million USD in 2013 (Nikolic, 2021).
Southern Bluefin Tuna
A photograph of a Southern Bluefin Tuna (Good Fish Bad Fish, n.d.)
While Southern bluefin tuna (Thunnus maccoyii) are the least populous of the three species, they span the largest geographic area, swimming across the waters of the entire southern hemisphere (Nikolic, 2021). As they are situated in the southern hemisphere, their migration habits are influenced by the local climate and spawn between the months of September and April (Nikolic, 2021).
Compared to other species of bony fish, including both Atlantic and Pacific bluefin tuna, Southern bluefin tuna have adapted to withstand much colder temperatures of up to 37°F (American Oceans, n.d.). However, the trade-off is that they are only capable of exploring shallow waters.
Chart and writing by Nico Carpo
References
American Oceans. (n.d.). How Long Do Bluefin Tuna Live?.
Good Fish Bad Fish. (n.d.). Southern Bluefin Tuna [Photograph]. https://goodfishbadfish.com.au/fish/southern-bluefin-tuna/
National Oceanic & Atmospheric Administration Fisheries. (n.d.). Atlantic Bluefin Tuna [Photograph]. https://www.fisheries.noaa.gov/species/atlantic-bluefin-tuna
National Oceanic & Atmospheric Administration Fisheries. (n.d.). Pacific Bluefin Tuna [Photograph]. https://www.fisheries.noaa.gov/species/pacific-bluefin-tuna
Nikolic, S. (2021, May 12). Bluefin Tuna Migration Explained. Fishing Booker. https://fishingbooker.com/blog/bluefin-tuna-migration-explained/
University of Michigan Museum of Zoology. (n.d., a). Thunnus thynnus. In Animal Diversity Web. Retrieved March 3, 2022, from https://animaldiversity.org/accounts/Thunnus_thynnus
University of Michigan Museum of Zoology. (n.d., b). Thunnus orientalis. In Animal Diversity Web. Retrieved March 3, 2022, from https://animaldiversity.org/accounts/Thunnus_thynnus