Our niece is getting aquasaurs, scientifically known as triops launcauditus, for her birthday. I did a bit of investigating to find out more about such odd-looking three-eyed creatures. Here are the highlights of digging through the web. You can find more details at the Netfysh Triops FAQ, MyTriops.com, the ever-popular Wikipedia, and the DiscoverThis.com FAQ.
Triops are living fossils. As a species, they've been around 250-350 million years. For comparison, dinosaurs began around 230 million years ago.
Triops have a most amazing adaptation to a niche environment: they do well in ponds that dry up. When the rains come, their eggs hatch. They grow rapidly, lay eggs, and live up to about 90 days. The eggs can survive being dry for 10-20 years until the next time the rain fills the pond. That means if you want more triops, siphon most of the water out of your aquarium (without sucking up the eggs at the bottom), let the rest dry and remain dry for two weeks, then add back distilled water to get the eggs to hatch.
Triops are also predators, though apparently when available they'd rather hunt slow moving vegetables than fast-moving animals. They are predators nonetheless, so mixing them with small fish is not recommended.