The Adaptations of the Cave Fish

Adaptive Comparisons of Cave Animals

Found at: http://www.reocities.com/kubyimm3/adap.jpg [thanks for saving the images!]
In a food-rich Mexican cave, just a few sweeps of the net yield as many as thirty finger sized Mexican blindfish. Indeed, these fish are so plentiful in certain caves that a hundred or more may be visible in just a few cubic yards of water. These closely related Mexican cave fish and a widespread surface form are so similar that some scientists think all may be subspecies of the same animal. In any case, the fish can interbreed, and residents of some caves show all degrees of eye and pigment degeneration. Here, a blind Mexican cave fish and its surface relative are compared.


Gliding slowly through the water, the blind cave fish Typhlichthys pauses occasionally to nose under rock ledges in search of isopods and other food. Vibration receptors on its head and sides detect movements in the water and guide it to its prey.

Typhlichthys subterraneus (Southern Cavefish).

The Cave Adaptations of a Fish. Now, imagine similar transformations for a mammal being adapted from the surface to the underworld...

References:
Mohr, Charles E. & Poulson, Thomas L., 1966, Our living world of nature: “The Life of the Cave”, McGraw-Hill, the World Book Encyclopedia and the U. S. Department of the Interior, 232 p., New York.

This continues my postings on Adaptive Comparisons of Cave Animals.

Note: At the end of the essay "The Simple and the Primitive: Some Cautionary Tales" (Dec. 2004), its writer declared:

"intelligent design, in striving to produce a historical narrative of life, is not going to be cut down by people raising philosophical objections."

Other cave-dwellers:

http://fdocc.blogspot.com/2006/01/new-27-cave-bugs.html

http://fdocc.blogspot.com/2006/02/cave-dwellers-known-since-1966.html

http://fdocc.blogspot.com/2006/02/more-adaptive-comparisons-of-cave.html

http://fdocc.blogspot.com/2006/01/laupala-cricket-variation.html