Four-eyed Fish (Anableps ssp.)
Yet another oddball in the seemingly unending parade of bizarre fish that inhabit brackish water environments, the four-eyed fish's protruding eyes give the animal a froglike appearance. Although not commonly available in the pet trade, this fascinating species is well worth learning about and searching for.
Four-eyed fish are found along coastal areas from southern Mexico to northern South America. Unique among all fish, the eye is divided into two parts by a horizontal band of opaque tissue. The fish spends nearly all of its time at the surface of the water, and positions itself so that this dividing band of tissue is at the interface of the air and water. The upper portion of the eye then scans the air for prey and predators, while the lower half does the same below the water.
Four-eyed fish are best maintained in aquariums only partially filled with water. In this manner, you will more easily be able to observe their unique habits and lifestyle.
These fish are always on the move and therefore require an aquarium with a good deal of surface area. They are also quite skittish in captivity, and are prone to injuring themselves when startled. For this reason, foureyed fish should be approached slowly and lights should never be suddenly turned on if the room is in complete darkness.
Four-eyed fish are best maintained alone or with noncompeting species such as mudskippers.
Four-eyed fish have evolved to fit a very specific niche within their environments. In common with many such animals, their dietary requirements are fairly specific. Four-eyed fish definitely prefer live foods such as small shrimp and particularly insects. Some have acclimated to frozen foods, but they seem to thrive best when provided with a more natural diet.