The fishes, blind or partially blind, living in the depths of the ocean bordering the American continents, are as follows: 1. Ipnops Murrayi Günther lives at depths varying from 955 fathoms to 2,158 and has the very wide distribution suggested by the localities from which specimens have been secured—viz., off the coast of Brazil, near Tristan da Cumba, near Celebes, latitude 24° 36′ north, longitude 84° 51′ west, and off Bequia. This is the only vertebrate in which no vestige of an eye has been found. Ipnops stands alone in a family. 2. The Brotulidæ have several members blind or with very much reduced eyes in various parts of the globe. Aphyonus mollis G. and B., 955 fathoms, and Alexeterion parfaiti Vaillant, 5,005 metres, are the only ones found in the neighborhood of America. 3. The Lophiidæ are represented by Mancalias Schufeldtii Gill, from a depth of 372 fathoms. Other blind species are found in foreign waters, while others with small eyes are found in American waters. The majority of deep-sea fishes have well-developed eyes.
The shore fishes have their blind representative in Typhlogobius californiensis St., which lives under rocks between tide water on the coast of southern and Lower California. I have elsewhere described the habits of this form. In the fresh-water caves of Cuba two blind fishes—Stygicola denta Poey and Lucifuga subterraneus Poey—have been found. Their relatives live in the ocean, Brotula barbata in Cuban waters; some of the others are blind and inhabitants of deep water.
The inland fresh-water fishes are represented by Gronias nigrilabris Cope, a catfish from cave streams of eastern Pennsylvania, and by members of the Amblyopsidæ, concerning which a more detailed account is given below.
The Amblyopsidæ.—The Amblyopsidæ are a small family of fishes allied to the Cyprinodontidæ. They are found in the Mississippi drainage basin and in certain southeastern streams. Three of the members of the family, the Chologasters, are provided with well-developed eyes, while four other species are cave fishes in the strictest sense, being blind and colorless. The distribution of the different members of the Amblyopsidæ is as follows:
Fig. 2.—The larva and adult of the Missouri cave salamander (Typhlotriton).
Chologaster cornutus is found in lowland swamps of the Southern States from the Dismal Swamp to the Okefinokee Swamp. Chologaster Agassizii is found in subterranean streams in Tennessee and Kentucky. Chologaster papilliferus has so far been found only in southwestern Illinois.
Amblyopsis is abundant in the cave streams of the Ohio Valley south of the east fork of White River.
Typhlichthys subterraneus inhabits the region south of the Ohio and east of the Mississippi. A single specimen of another Typhlichthys has been found north of the Ohio River in a well at Corydon, Indiana. Troglichthys rosæ inhabits the caves west of the Mississippi in Arkansas and Missouri.
Chologaster.—Mr. E. B. Forbes secured a school of Chologaster papilliferus for me, and he wrote: “The little fishes were found under stones at the edges of the spring very close to the bluff, and when disturbed they swam back under the cliff.... None were found at any considerable distance from the face of the cliff.” I found the Chologaster Agassizii to act similarly in the river Styx, in Mammoth Cave. As soon as my net touched the water they darted in under the ledge of rock at the side of the little pool in which I found them.