TRUE: Ancient Greek dentists used the venom from the stingray’s spine as anesthetic.
TRUE: Doctors once used Asian carp as a test for pregnancy.
FALSE: Amazon explorers took a medicine derived from coral to fight off malaria.
TRUE: One of the rarest sharks is called a megamouth shark. TRUE: Some sharks can increase their size by swallowing large amounts of water. FALSE: Like dolphins, sharks do not have scales.
Sharks are covered with small, tooth-like scales called dermal denticles. Sharks feel smooth to the touch because their scales are designed to reduce drag. Megamouth sharks and swell sharks are both real animals! Megamouths sound scary, but they’re filter feeders and prefer plankton. Swell sharks, as their name implies, can swell up to twice their normal body size just by swallowing water. What’s your favorite shark?
TRUE: Both male and female walruses have extended tusks. TRUE: Walruses can slow their heartbeat while diving underwater to keep warm. FALSE: To maximize the ratio of insulating blubber to body size, walruses have a lower blood volume than most land animals their size.
Because walruses spend so much time underwater, they store oxygen in their blood and muscles. They actually have an enormous blood volume–two to three times as much as other land animals their size. Do you know any interesting ways other animals have adapted to their surroundings?