Hagfishes (Myxini) are sometimes referred to as slime eels and occasionally as snot snakes, but they are neither eel nor reptile. They are fishes, but belong to an exclusive group called cyclostomes, ...
When two animals look the same, eat the same, behave the same way, and live in similar environments, one might expect that they belong to the same species. However, a tiny zooplankton skimming the ...