If you want to learn more about yellowfin tuna (Thunnus albacares) then you’ve come to the right place. yellowfin tuna fall underneath the Thunnini tribe and albacares (“white meat”) species name, commonly known as “Ahi” at restaurants, grocery stores and seafood markets. It’s a popular sport fish around the pelagic waters of tropical and subtropical oceans worldwide like the eastern Pacific Ocean. If you are a Southern California native like myself then you have to go yellowfin tuna fishing. Season starts in June as soon as the waters begin to warm and goes to September, but can appear sooner or later depending on the summer water temperatures.
These fish are absolute beasts, reaching weights of up to 450 pounds and lengths of nearly 7 feet, making them one of the ocean’s fastest and strongest predators. Yellowfin tuna have a classic torpedo-shaped body with dark metallic blue backs and silver bellies which have over twenty vertical lines and yellow sides. Their anal and dorsal fins are long and can be commonly mistaken for yellowtail tuna which are biologically smaller. A major distinguishing feature are the bright yellow finlets, bordered by a narrow black band located at the backside and lower side of the fishes body. These features are what give the yellowfin tuna it’s well-known name.
These creatures are amazing and can reach speeds of up to 50 mph by folding their fins into special indentations along the body, streamlining their bodies as much as possible. This allows them to reduce drag and boost speed underwater.
WHERE TO FIND YELLOWFIN TUNA
The yellowfin tuna inhabits the epipelagic (waters from the surface of the sea down to around 660 feet) zone of the ocean near the central western and eastern hemispheres, running through the eastern Pacific, southern Atlantic and Indian oceans. These water temperatures range from 64-86 Fahrenheit (18-30 Celsius). Despite spending most of their time in depths shallower than 300 feet, they have been known to occasionally dive down to depths greater than 3,000 feet.
With the rising temperatures in recent years, yellowfin have been spotted in greater numbers in areas such as San Diego, California. Yellowfin tuna are partially warm-blooded, and the warming waters are drawing them even closer to shore. They are typically found 40 to 70 miles offshore but as temperatures increase and ocean life thrives, the local bait draw the fish in much closer.
When it comes down to it, warm clear waters with plenty of food is where you will find these fish. They are aggressive predators who prey on crustaceans, squid, and fish such as sauries, mackerel, flying fish, and other fast-moving baitfish. What’s odd about these fish is that they are known for schooling under drifting objects such as boats, beds of sea grass and driftwood seeking shade and shelter.
YELLOWFIN BEHAVIOR AND DIET
These magnificent species are known to travel in large schools, although they are more than capable of running down prey individually. Sometimes they are seen traveling with other species of tuna, dolphins, whale sharks and even vessels.
What’s unique about yellowfin is that they are phenomenal at thermal-regulating. This means that they have the ability to regulate their body temperatures allowing them to dive down thousands of feet even though they’re partially warm-blooded and spend the majority of time in warmer waters only a few hundred feet or less.
When fishing for yellowfin it’s good to understand what they eat. A study done by Watanabe found 37 families of fish and 8 types of invertebrates in a yellowfin’s stomach. Fish species consumed by yellowfin tuna include mackerel, anchovy, pilchard, flying fish, squid, shrimp, lobster, octopus and even other tunas. What most of these baits have in common is that their habitats are in shallower waters. Research has shown that yellowfin are sight-oriented, and as a result they feed during the day and close to the surface where prey is easily visible. This would explain why they prefer feeding on flying fish.
Yellowfin tuna have a conservation status of “Near Threatened.” Throughout the past decade they have become an increasingly popular item in restaurants, homes, and sportfishing charter boats around the world due to their highly migratory nature.
Yellowfin are absent in the Mediterranean Sea and have little evidence of long-range migration. This means there’s very little cross breeding between the western, eastern and central Pacific Ocean.