Yellowtail vs. Yellowfin Tuna: The Key Differences

Yellowtail and yellowfin tuna are completely different fish species, despite their striking similarities. Yellowtails are Atlantic and Pacific fish in the genus Seriola of the family Carangidae, usually considered amberjacks, while yellowfin tuna is a species found in pelagic waters across the globe. Both fish have similarly bright yellow colors on their dorsal, anal, and tail fins, which can be a source of confusion. Continue reading to learn more about the key differences between the yellowtail and yellowfin tuna. 

Key Differences Between Yellowtail and Yellowfin Tuna

Although the yellowtail and yellowfin tuna share many similarities, size is a key distinguishing feature between the two species. Other key differences between the yellowtail and yellowfin tuna include their scientific classification, appearance, diet, habitat and distribution, lifespan, and conservation status.

Scientific Classification

The taxonomic name of the yellowtail is Seriola lalandi. Seriola is a diminutive feminine form of seria, a more extensive earthenware pot. The second word, lalandi, comes from a naturalist named Monsieur de Lalande, who was the first person to tell zoologist Achille Valenciennes about the yellowtail species. 

The yellowfin tuna’s taxonomic name is Thunnus albacares, a combination of two Latin words: albus, which means white, and caro, meaning flesh. Yellowfin tuna is commonly known as Ahi, a Hawaiian word that means fire, due to old Hawaiian fishing methods in which handmade twine was attached to the canoes to catch these large, powerful fish. When a tuna was hooked, it would swim away so fast that the friction of the line against the wood of the canoe would generate enough heat to cause it to smoke, and sometimes even start a small fire.  

Size

The yellowtail is a medium-sized fish with a long, fusiform body that can grow up to 30 inches long and weigh 80 pounds or more.

The yellowfin tuna is among the largest tuna species, weighing up to 450 pounds with a total length of up to 7 feet. However, the yellowfin tuna is significantly smaller than the Atlantic and Pacific bluefin tuna, which can weigh over 990 pounds.

Color

The upper dorsal side of the yellowtail is blue, with a silvery-white color on its lower flanks and belly. It also has a distinct bronze-colored stripe that runs along the middle of its body and transitions near the tail to a yellow color. Like the yellowtail, yellowfin tuna also has yellow fins. However, the yellowfin tuna is characterized by a dark blue back and yellow side, which fade to silver around the belly.

Diet

Yellowtail and yellowfin tuna are very active predators. However, their diet preferences slightly differ between the two species. The yellowtails’ diet consists of squids, garfish, sardines, herrings, and anchovies. Yellowfin tuna prey on crustaceans, squid, and mollusks.

Habitat and Distribution

Yellowtails spend most of their time near rocky reefs and adjacent sandy areas along the coast. They occasionally enter estuaries and occupy shallow water down to depths of up to 164 feet. However, some yellowtails have been caught at depths approaching 1000 feet.. 

Yellowtails were once thought to be a single species found worldwide, but recent genetic analysis has shown that what was once considered S. lalandi actually comprises several distinct species or populations. The true S. lalandi is now recognized as native to the Southern Hemisphere, while related species such as S. aureovittata (the yellowtail kingfish) are found in the Northern Hemisphere

Yellowfin tuna are found in both the Northern and Southern Hemispheres throughout the Pacific, Atlantic, and Indian Oceans. Though they are typically found in the uppermost layer of the ocean, yellowfin tuna are also capable of diving to considerable depths. Most yellowfin tuna range in the water column’s top 330 feet.

Reproduction 

Both yellowtails and yellowfin tunas release their gametes into the water column, where external fertilization occurs. During the spawning season, which is in the summer, female yellowtails may release up to 150 eggs at a time. About 100 of these eggs are likely to be fertilized.

Female yellowfin tuna produce an average of one million to four million eggs every time they spawn. They breed all year round, with the peak spawning season occurring in the summer. However, a small percentage of yellowfin tuna eggs reach maturity, with only one in a million making it to the age of three. The rest fall prey to a wide array of threats from surface-dwelling birds and jellyfish to deep-sea hunters and human predation.

Lifespan

Yellowtails and yellowfin tuna become sexually mature between one and three years of age. Most yellowtails live for five to six years, while yellowfin tuna have a slightly longer lifespan of seven to eight years.

Conservation Status

With relatively healthy populations and widespread distribution, the yellowtail is listed as ofLeast Concern on the IUCN Red List, based on the most recent assessment from 2015. The yellowfin tuna is currently listed as of Least Concern on the IUCN Red List, following an update in 2021.