There might be many fish species in the ocean but there’s hardly one that’s as unique and majestic as the Bluefin tuna. It is big, fast, smart and gorgeously colored, boasting incredible game qualities and unrivaled culinary value. This has made it a common topic of discussion as many people ask questions like; ‘How big is the Bluefin tuna?’ ‘What does Bluefin tuna eat?’ ‘Why do great white sharks eat Bluefin tuna fish?’ and many others.

Facts about the bluefin tuna

For starters, it’s important to note that there are mainly two species of bluefin tuna; Pacific bluefin and Atlantic bluefin, which is generally the largest and most endangered species. The Atlantic bluefin tuna is native to both the eastern and western Atlantic Ocean while the Pacific bluefin can be found in the North Pacific, ranging from the East Asian coast to the western coast of North America.

Despite its big size, the Bluefin tuna doesn’t start out as a large fish. Just like many open ocean bony fishes, the Bluefin tuna when hatched is an extremely tiny larva. Measuring only a few millimeters in length and a few hundredths in gram. The female Bluefin tuna produces millions of eggs each year but they most get are eaten by big fishes before they attain fully size and this dramatically decreases their numbers. 

Although Bluefin tunas don’t grow as fast as other types of tuna, those that survive undergo an amazing transformation that see them move from being nearly microscopic to being one of the largest open ocean predators. So what do Bluefin tuna larvae eat? At young age, the larvae eat tiny zooplankton and their prey increases as they grow bigger.

What do bluefin tuna eat?

Within three to five years, their size increases to lengths of 3 feet and the juvenile bluefin tunas switch to eating fish, squid and crustaceans. Two common questions many people ask is ‘What do Atlantic Bluefin tuna eat?’ and ‘What do pacific Bluefin tuna eat?’ Adult fish are tremendous predators and they almost constantly gorge themselves on invertebrates and baitfish such as herring, bluefish and mackerel. 

Their voracious appetite means that bluefin tuna have to hunt for food frequently and this sometimes makes them pass through waters as cold as 16 degrees Fahrenheit. Not many fish can accomplish this feat but the bluefin tuna is able to do this because it is a warm-blooded animal. 

In other words, their body allows them to maintain a temperature that’s higher than surrounding waters. This explains how they survive in cold waters off Newfoundland and Iceland as well as the tropical waters of the Gulf of Mexico and the Mediterranean Sea, where they go to spawn each year. 

Furthermore, when the bluefin tuna has feasted on a prey, it tends to stay in waters that allow it remain at an optimum temperature to promote rapid digestion of the meal. Too high or too low an environmental temperature and the increased demands of digestion can strain the cardiovascular system. So there’s a good chance that a bluefin tuna will watch a prey go while it waits for the food it ate to be fully digested. 

Adult bluefin tunas can weigh up to 450 pounds and more but they are also prey to other bigger fishes like killer whales, billfishes, pilot whales and some open ocean shark species. Nonetheless, data from a 2017 report estimates that there are 1.6 million Pacific bluefin in the Pacific. While the Atlantic bluefin tuna population is currently unknown even though experts believe it is on a decline due to overfishing. 

Why do great white sharks eat bluefin tuna fish?

Moving on from the subject of what bluefin eat. Another question that begs for answers is ‘Why do great white sharks eat bluefin tuna fish? As earlier mentioned, the bluefin tunas prey on other fish species but they get eaten by larger predators like great white sharks. 

For starters, bluefin tunas grow to a maximum 4m in length and can weigh up to 2,000 pounds. In contrast, great white sharks can grow to an astonishing 6.4m in length and a maximum weight of 2400 pounds. Obviously, great white sharks are larger than bluefin tunas and their size makes them predators to many smaller marine species including bluefin tunas. Even marine mammals and other sharks are not out of harm’s way. 

While the size of the great white shark is an advantage when hunting for food, it doesn’t find it easy preying on large animals like bluefin tunas. They are also very strong and big predators in their own rights. However, its strong jaws and powerful bite force of nearly 4000 PSI helps in such times. 

Another reason great white sharks eat bluefin tuna fish is that they are picky eaters. Scientific experiments have shown that this species of sharks do not feast on everything but rather pick out foods that are high in calories and leave the rest. Incidentally, bluefin tuna is relatively high in fat and calories, making them a favorite for great white sharks who love to feed on energy-rich prey. 

The mode of attack for big animals like bluefin tuna fish is quite different from that of other preys. Leveraging their sharp senses of sight, smell and electro-reception as well as their unique muscles arrangement that helps them cut rapidly through water, great white sharks stalk their target, clamp them from the surface and only begin to feast only when the animal is immobile. 

In a nutshell, the answer to ‘why do great white sharks eat bluefin fish facts’ is simply because they have larger body size and also because they have a liking for animals that are rich in calories.  

All-in-All

The bluefin tuna is one of the largest, fastest and most gorgeously colored of all the open ocean’s fishes. It is also one of the strongest and smartest predators, thanks to its superbly streamlined body that allows for speed and endurance. Adult bluefin tunas eat a variety of prey but they research suggests that they prefer pelagic fishes and invertebrates that they can swallow whole.