What is "four-eyed fish"

n. A genus (taxlink Anableps genus) of fish in the family ''(taxlink Anablepidae family)'' having eyes raised above the top of the head and divided in two different parts, so that they can see below and above the water surface at the same time.

The four-eyed fishes are a genus, Anableps, of fishes in the family Anablepidae. They have eyes raised above the top of the head and divided in two different parts, so that they can see below and above the water surface at the same time. Like their relatives, the onesided livebearers, four-eyed fishes only mate on one side, right-"handed" males with left-"handed" females and vice versa. These fish inhabit freshwater and brackishwater and are only rarely coastal marine. They originate from lowlands in southern Mexico to Honduras and northern South America.