Bluefin Tuna

Not many marine mammals or fish can follow Bluefin tunas, resulting in them having no natural enemies in the wild. As an opposite the most other bony fish, which are cold blooded, the Atlantic Bluefin have endothermic circulatory systems, called a countercurrent exchanger, helping them to maintain their body temperature and giving them an edge in hunting.

Not only does the Bluefin share the sharks titles as a top predator, they also have in common with having to be on the move at all times. If not swimming with the mouth open, oxygen cannot be retracted from the water to oxygenate the blood. Even though having a lack of natural enemies, humans are the greatest threat. Being highly valuable for the meat, illegal fishing is a not uncommon theme for the Bluefins. Female Atlantic bluefin tuna lays millions and millions of eggs per year, with hatching shortly after being fertilized, the overfishing is still more than the population can rebound with. This sub-species of tuna is known for migrating across the vast open-ocean from the Mediterranean sea all the way to the Gulf of Mexico.