According to Helablog:
Filled with colored water, each 7-centimeter long key ring encapsulated either one Brazil turtle or two small kingfish, and is filled with “nutrient rich” water, by which vendors claim allow the animals to live for several months. Unfortunately, after your few months are up, you have a carcass key chain.
Experts say the animals will likely run out of oxygen and suffocate before they would die from any sort of nutrient deprivation.
<sadface> I grew up with pet turtles, and this makes me so, so sad! And on a visceral level, who wants a dead animal swinging from your keychain?