The hydra is a Lovecraftian-looking microorganism with a mouth surrounded by tentacles on one end, an elongated body, and a foot on the other end. It has no brain or centralized nervous system.

Three environmental zones which can influence the activation of the feeding response of Hydra littoralis are termed the macro-, micro-, and ultramicro- environment. The first consists primarily of the ...

Hydra eat by ripping apart their own skin, a mechanism that’s well known but had never been closely observed. Biophysicists at the University of California, San Diego, genetically engineered hydra to ...

In steady state Hydra, one group of stem cell derived cell types, nematocytes, are regularly turned over due to feeding. The effects of removal of this normal physiological stimulus to cell turnover ...