- ALB: albacore (Thunnus alalunga);
- BET: bigeye tuna (Thunnus obesus);
- BFT: bluefin tuna (Thunnus thynnus), alko known as northern bluefin;
- SBT: southern bluefin tuna (Thunnus maccoyii), considered a subspecies of Thunnus thynnus by some ichthyologists;
- SKJ: skipjack (Katsuwonus pelamis), also known as arctic bonito, oceanic bonito and as aku in Hawaiian;
- YFT: yellowfin tuna (Thunnus albacares), named ahi in Hawaiian.
The blackfin tuna (Thunnus atlanticus) obviously did not make it into the three-letter-acronym league of tunacronyms. Maybe as blue-black back tuna (BBT) or golden-yellow-banded tuna (GBT or GYT) it has a better chance. Richard Ellis, in Chapter 9 with the title The Bluefin's Popular Little Cousins in his Tuna book [1], characterizes the blackfin, colorwise, as follows: “the blackfin is blue-black on the back, with a golden yellow band that runs from eye to tail but fades soon after death.”
Reference
[1] Richard Ellis: Tuna • Love, Death and Mercury. First Vintage Books Edition, July 2009.