Ask most people what makes a fish a fish and they will list key traits, such as fins, scales, and perhaps most importantly, ...

Each time the tide recedes, most fish escape certain death by following the water. But not the prickleback. This uncanny eel-like fish has a trick up its sleeve — it can breathe air.

DESCRIPTION: Pacific lamprey are slender, eel-like fish that are dark blue or brown in color and grow to about 30 inches long. They have lateral eyes, lack paired fins, and have no scales. Adult ...

Newly published research from U.S. Geological Survey looked at more than 25 years of annual sea lamprey data, including annual adult populations of the eel-like fish and the number of wounds ...