Triops (The Amazing Three-Eyed Tadpole Shrimp)
Common Names: Tadpole, dinosaur or shield shrimps
Scientific: Various species in the family Triops
Triops are a type of crustacean commonly found in temporary pools of fresh and brackish (mix of fresh and saline) waters that are filled after seasonal downpours of rain. Because they inhabit pools that routinely dry out, Triops eggs can survive prolonged periods of desiccation.
The dried eggs are also tolerant of extreme heat and can survive temperatures up to 208 degrees Fahrenheit (98 degrees Celsius) for 16 hours whereas the adults cannot survive temperatures great than 93 degrees Fahrenheit (34 degrees Celsius) for 40 hours or 104 degrees Fahrenheit (40 degrees Celsius) for 2 hours. I'm not exactly sure how scientists came up with figures this exact, but I think it may have involved cooking these poor critters in some sort of slow-cooking oven-like device.
Triops also have some quirks to their reproduction. Although most species of Triops reproduce sexually with separate male and females, some populations are made up of hermaphrodites that fertilize their own eggs internally. In one species (Triops cancriformis) it was found that northern populations were mostly comprised of hermaphrodites while southern populations mostly reproduced sexually. Although having the ability to breed with yourself might be useful if you're the only Triops in the pool, it is still a mystery as to why the concentration of hermaphrodites varies with latitude in this species.
There is evidence of Triops species in the fossil record from around 300 million years ago and they are as a whole still quite similartoday, granting them the label of 'living fossils' as a result.
Triops were around when the Earth had a single giant continent called Pangea, they saw the rise and fall of the dinosaurs and today there are Triops species native to every continent on Earth except Antarctica.
The genus name Triops is dervived from a combination of two Greek works, trias meaning three and ops meaning eye. Triops do indeed posess three eyes: two adult compound eyes and a naupliar eye between and above them that is retained from a larval (juvenile) stage in its life cycle known as a nauplius. The naupliar eye is the only eye present during the nauplius stage of their lifecycle, it is a simple eye lacking the complexity of the adult compound eyes and is better suited for picking up changes in light than clearly defined images.
Due to their ability to withstand desication, the dried eggs are often sold to be hatched as novelty pets in a similar fashion to brine shrimp (another crustacean marketed and sold under the name sea monkeys). They are a little larger than sea monkeys though with most Triops species used for this purpose growing up to 6cm in captivity. Although I'm sure their extra size makes them a somewhat more appealing pet they are still a long way off reaching puppy or kitten status, they are however an interesting creature never-the-less.