Yellowfin Tuna
Thunnus albacares

"AKA" as allison tuna, long-fin tunny, Autumn albacore and in Hawaii as shibi,

Description:   Not only is the Yellowfin tuna streamlined and powerfully built for speed and endurance; it retracts its fins for smoother water flow over it's body.   The anal and dorsal fin are long and bright yellow.  The body is a beautiful dark metal-like blue displaying approximately 20 vertical lines.  It's has a silver belly.  The caudal fin has a distinct raised "M" shape at the forked center. The body profile appears somewhat flattened behind the second dorsal and the anal fin.

The adult yellowfin tuna has a relatively long pectoral fin that is almost one third of the body fork length.   The younger tuna looks very similar to the bigeye tuna. The juvenile tuna also has more obvious oval colorless patches and vague broken vertical bars of white.

The tuna can reduce drag with caudal peduncle keels found near the tail fin, reducing water turbulence made by the tail fin and lowers the drag of that body part.   Behind their fins, tunas have a series of sail-like finlets on the bottom and top of their body allowing their tail to move efficiently in undisturbed waters. When the first dorsal fin is not needed, it folds down into a grove also causing a reduction in drag. 

The heart of a tuna is as much as ten times larger, pumping three times more blood and having three times higher blood pressure than other fish of equal size.  Because they have a much higher number of red muscle than average fish they are able to cruise with more efficiency at higher speeds.  Their gills are 30 times larger in surface area than other fish and since they cannot open and close their gill covers with their opercular muscles to force water over their gills, they must swim at a speed of 26 inches per second to get the water flow needed for oxygen. 

The Yellowfin tuna is warm-blooded and is capable of heating their bodies 45 - 50ºF warmer than the water that surrounds it. This is accomplished by a network of veins and arteries called "rete mirabile" that will trap or dump their body heat.  This enables them to keep their muscles warm and move faster with more efficiently.  Because the tuna must consume nearly 5% of their body weight daily it continually swims with its mouth open forcing water over the gills and  greatly charging their muscles with oxygen. No other fish can swim as fast or as far as tunas. 
 
Similar Fish:    Albacore, Northern Bluefin Tuna (but have wider and longer pectoral fins and a longer second dorsal fin) and the Bigeye tuna

Where Found:   The yellowfin tuna lives in the open waters of both tropical and subtropical waters near the surface or as deep as 600 feet.  Yellowfin tunas swim with others fishes of the same size, such as dolphins, porpoises and whale sharks.  They are found near shore in clean warm currents, but are more common on the Continental Shelf waters.  They avoid dirty waters.  These fish are rarely seen near reefs, but are found near floating debris and other objects.  Yellowfin tuna will leave their habitat at night and travel eight or nine miles offshore to feed and then return to the same exact spot or object (floating debris) the next morning.

You will not find the yellowfin tuna in the Mediterranean Sea. 

Size:     Commonly, yellowfin tuna are approximately 80 lbs. and once in a while reach 200+ lbs.  The maximum unofficial size recorded is 400 lbs.

State Record:     325 lbs. Hawaii, Pacific Ocean - Lanal, by angler Joey Cabell 7/13/1990

World Record:   388 lbs. 12 oz., Mexico, 1977

Bait used:   They will take fresh-cut fish flesh strips, small live bait, cast lures or trolled bait.

Tactics to catch:    Commercial fisheries use purse seines (nets that close like that of a purse string not allowing the fish to swim downward to escape) and longlines that can stretch many miles with hundreds of baited hook. I might add these fisheries are likely to catch many other kinds of fish without discrimination - including the endangered sea turtle. 

Most anglers use the trolling and chumming methods.  When trolling, multiple lures are pulled in the boat wake while traveling at seven to eight nautical miles per hour.  The single hook lures with plastic skirts are common with chains or spreader bars of lures.   Green is a color that yellowfin tuna are most attracted to.  The idea to to make the tuna think it is attacking a group of  irritated bait-fish by wiggling and sparkling the lures.

Chumming is when you get the fish's attention by baiting the hook while the boat is anchored or drifting.  Often cut bait of silver hake or butterfish is commonly used.  Be prepared with strong enough reels, rods and lines for the size fish you want to catch.  Using lighter 30 lb. tackle might be popular, but hardly an easy catch for a 150 yellowfin tuna.  If you are an inexperienced angler after transferring your rod to a back harness and/or a gimbal belt and take your stance, be prepared for a fight.  It is easy to tire when you hook a large tuna, but the pure excitement can give you a boost of energy.  Often the tuna will pretend to be hurt and get away when you least expect it.  These fish are very powerful and you must use the best in tackle and gaffs!  

If it is your decision to release the tuna be careful not to cut or bruise it.  If the tuna is exhausted swim it along the side of your boat allowing it to get a chance to release carbon dioxide and replace its depleted oxygen supply. 

Climate   (water temperature range):     Yellowfin tuna prefer water temperatures of 17-27 º C.  ( 70 - 84 ºF.)

Spawning habits:   The yellowfin tuna reach sexual maturity at 2-3 years of age and can produce several million eggs, while a yellowfin tuna reaches 4 years of age can produce over eight million eggs and has less predators.  The Gulf of Guinea is the primary spawning grounds in the Atlantic with some spawning occurring in the Gulf of Mexico. Peak spawning occurs during the summer months.   They spawn several times a year in the open sea at 78ºF. or above.

Table food?    These fish are excellent table fare.  They are often baked, grilled, seared rare to medium rare. They are most known by popular brands of canned tuna.  They are touted as an excellent sashimi (raw thinly sliced pieces and served with a
dipping sauce).  It taste much like sirloin bottom tip when thoroughly cooked. Yellowtip tuna has a medium to firm texture and is also sometimes smoked or dried.   Yellowfin tuna will spoil faster than the albacore or bigeye tuna loosing it's natural red color. Tuna that is "burnt" (paler in color due to stress or water temperature) is said to be dryer and with less flavor when cooked.  The smaller pink tuna flesh has less fat content and is best for grilling. It is especially popular as "blackened" as in Cajun cuisine.

Consumption Concerns:   Environmental Defense has issued a consumption advisory for longline-caught yellowfin tuna.  Due to elevated levels of mercury. (No consumption advisories are listed for troll/pole-caught yellowfin as these gear methods catch younger tuna with lower mercury levels.) 

Feeding habits:     The yellowfin tuna eat other fish, krill, pelagic red crab, squid and crustaceans.  They feed well down into the water column or near the surface.  Fish leave a scent trail of oils, proteins, and amino acids from their slimy body and the yellowfin tuna has a real good sense of smell.  By picking up these tiny traces and are able to actually track down their prey.

Remarks:    Magnetite is found in the neural pits of the tuna's snout.  This is a mineral used by the tuna to sense the magnetic field of the earth for navigation.  

The yellowfin tuna has a life span of approximately eight years.