Amblyopsidae
The Amblyopsidae are a fish family commonly referred to as cavefish, blindfish, or swampfish. They are small freshwater fish found in the dark environments of caves (underground lakes, pools, rivers and streams), springs and swamps in the eastern half of the United States. Like other troglobites, most amblyopsids exhibit adaptations to these dark environments, including the lack of functional eyes and the absence of pigmentation. More than 200 species of cavefishes are known, but only six of these are in the family Amblyopsidae. One of these, Forbesichthys agassizii, spends time both underground and aboveground. A seventh species in this family, Chologaster cornuta, is not a cave-dweller but lives in aboveground swamps. Description Amblyopsids are generally small, the northern cavefish (largest species in family) reaching up to in length. The amblyopsids are probably ancient in origin. Adaptations common to many cavefish include reduced susceptibility to light, pigment loss, or reduction in skin scales, as well as development of chemoreceptors in the sensory organs of the body surface and the lateral line. Three species exhibit efficient metabolism during swimming, as compared with a group of non-cave fish, and many cavefish species exhibit slender bodies adapted to swimming in fast-flowing waters. The cave-dwellers