Source: The San Tan Valley, AZ weather data displayed above is derived from the NOAA (National Oceanic and Atmospheric). Air quality and pollution data is derived from the EPA (United States Environmental Protection Agency).
A hydra is a small multicellular organism in the genus of the same name. These tiny animals are found in fresh water all over the world, and they have a number of distinctive traits that make them interesting to scientists.
Although hydra are fairly simple animals, the stinging cells which they use to catch their prey are quite complex structures. They have a number of different types of stinging cells, called nematocysts, on their tentacles. Coiled tubes are shot out at any passing prey which has had the misfortune to touch a tentacle.