Did you know that delicious yellow corn we've all come to love is a human invention. It is a plant that does not exist naturally in the wild, and can only survive if planted and protected by humans. Scientists believe people living in central Mexico developed corn at least 7000 years ago. It was started from a wild grass called teosinte. ...

The Mexican tetra (Astyanax mexicanus) is a blind, freshwater cave fish native to central and eastern parts of Mexico. Growing to a maximum total length of 12 cm (4.7 in), this species is notable for having no eyes or pigment; it has a pinkish-white color to its body (resembling an albino).

The Mexican tetra spends most of its time in midlevel water above the rocky and sandy bottoms of pools and backwaters of creeks and rivers of its native environment. Coming from a subtropical climate, it prefers water with 6.5–8 pH and a temperature range of 20 to 25 °C (68 to 77 °F). In the winter, some populations migrates to warmer waters. Its natural diet consists of crustaceans, insects, and annelids.

Given their peaceful nature, this species is popu ...