Triops, which date from the Triassic period, long before the dinosaurs prowled the Earth, lay eggs which do not hatch unless they are in water.
A mature Triops is three centimetres long, orangey-red and shrimp-like, and is best at home in a jam jar. Their attraction is that children can spend endless hours watching them sift sand for food. When boredom sets in, the Triops can be allowed to die, their eggs dried out and left dormant until the next rainy day.
The Triops package costs pounds 6.99, and for that you get eggs, a jar and food. After hatching, the Triops live for about 70 days. Their eggs can then be hatched again or allowed to lie dormant. Unhatched eggs can survive for up to 100 years.
Triops originally lived in parts of the world which were hot, but also experienced heavy rain. They evolved to survive long periods of drought, their eggs lying dormant for years in dried-up pools until the rains returned.
The educational toy company Interplay, which distributes Triops in this country, found the eggs hatch as well in British jam jars as they do in their natural environment.
Julian de Barsham, a partner in Interplay, said: "The brilliant thing about Triops is you start off with a dry packet and you end up with a living creature."
Twelve-year-old Carrie Hinton, from Yately, in Surrey, has watched one set of Triops go through their life-cycle. "Some children don't want a pet forever, so you just dry them out," she said. "It's not a life-long thing."
Triops first went on sale in the United States, where they have met with huge success. Mr de Barsham said: "Every child that sees them goes: `Wow!' These creatures look like science fiction and have survived unchanged for millions of years in suspended animation, and children love learning about that."
Meanwhile Bandai, the makers of the electronic version of the resurrecting pet, Tamagotchi, have a trick up their sleeve to beat the threat from Triops.
They have just launched DigiMon, a fighting Tamagotchi which can be plugged in to other machines and made to fight. Like Tamagotchi, DigiMon must be electronically fed and exercised to keep it happy; but it must also be trained to be prepared for battle. Unlike the original Tamagotchi, to keep parents happy, DigiMon has a sound-off button.Reuse content