What is a fish that travels the farthest?

That's a tough question! It's hard to definitively say which fish travels the farthest since we can't track all of them. However, there are some strong contenders for the title of "longest-traveling fish":

* The Ocean Sunfish (Mola mola): While they don't travel vast distances in a single journey, they have the largest recorded migration for a fish. A study showed one individual traveled over 12,000 miles in 6 months! They are also known for their long-distance migrations across oceans.

* The Atlantic Salmon: These fish are known for their epic journeys from freshwater rivers to the open ocean and back. They can travel thousands of miles in their lifetime.

* The Leatherback Sea Turtle: While not a fish, these turtles are closely related to them and migrate vast distances across the globe, often exceeding 10,000 miles.

Ultimately, it's hard to say for sure which fish travels the farthest, but these examples showcase the incredible journeys that some marine creatures undertake.