The tunas in the Gulf of Mexico are from the family “scombridae” which includes the mackerels, bonito and tunas. If ever there was a fish designed for hunting with speed it’s the tuna.
The one tuna in the Gulf that people are most familiar with is the yellowfin (Thunnus albacares). This fish, like all tunas, is easily identified by its dorsal an ventral finlets behind the anal and dorsal fins, a crescent moon shaped tail and keels close to the tail. This tuna has bright yellow finlets and with second dorsal and anal fins so elongated that they almost reach to the base of the tail. The yellowfin is found worldwide in tropical waters and can go as far north as Maine in the Atlantic. The world record for yellowfin is 388 pounds and fish can be almost six feet in length. Like the rest of the tunas the yellowfin is an open ocean species, is a schooling fish and loves to follow the “edge”. The “edge” is that area of the ocean where cold and warm waters meet. If you can find the “edge” you’ve just increased your chances of meeting up with one of these fish.
The bluefin tuna (Thunnus thynnus) is the largest of all the tunas. The world record was caught off Nova Scotia, Canada in 1979 and weighted 1,496 pounds. It has the same identifying traits as the yellowfin, without the yellow coloration and elongated second dorsal and anal fins. Its pectoral fins, when pressed against the body. do not reach the gap between the first and second dorsal fins. In the Gulf, bluefin spawn off south Florida and in the Florida straits from May through early July. The younger fish stay in the warm tropical warms with the adults heading north and south to the Polar Regions in search of food. Like a teenager, the bluefin and all tunas have high metabolic rates and need to eat as often as possible so they will follow the food wherever it goes. Remember, the lions are never far from the zebras.
The blackfin tuna (Thunnus atlanticus) is a small tuna and gets to only around three feet in length with the world record weighting in at 42 pounds in 1978. It can be easily confused with the bigeye (Thunnus obesus) and the albacore (Thunnus alalunga) even down to counting the gill-rakers (24-25). The blackfin is a local and ranges from Massachusetts to Brazil and the Gulf of Mexico. It is a strong schooling species, will run in mixed schools with skipjacks and stays in the warmer waters of the Gulf seaward of the continental shelf. The blackfin’s favorite food is squid.
Other members of tuna family in the Gulf include the very small bullet tuna (Auxis rochei) and the bonito (Sarda sarda), which is not the little tunny (Euthynnus alletteratus). Remember, common names are often times very confusing. For instance, what’s a green trout?