San Tan Valley 10 Day Weather. 1  Wednesday:The San Tan Valley forecast for Apr 19 is 83 degrees and Sunny. There is 20 percentage chance of rain and 4 mph winds from the West-Southwest. 2  Thursday:The San Tan Valley forecast for Apr 20 is 77 degrees and Sunny. There is 11 percentage chance of rain and 7 mph winds from the West.
Hydra, genus of invertebrate freshwater animals of the class Hydrozoa (phylum Cnidaria). The body of such an organism consists of a thin, usually translucent tube that measures up to about 30 millimetres (1.2 inches) long but is capable of great contraction.
Hydra &mdash; Classifications. Scientists aim to describe a single 'tree of life' that reflects the evolutionary relationships of living things. However, evolutionary relationships are a matter of ongoing discovery, and there are different opinions about how living things should be grouped and named. EOL reflects these differences by supporting several different scientific 'classifications'. Some species have been named more than once.