A team of biologists and physicists has uncovered in detail the dynamic process that allows the multi-tentacle Hydra, a tiny freshwater animal distantly related to the sea anemone, to open and close ...

As a member of the Phylum, Cnidaria, hydra arose early during metazoan evolution before divergence of the protosome and deuterostome branches. Its body plan is organized as a gastric tube with a mouth ...

The hydra, a small freshwater creature, tears itself apart every time it gets hungry. Rather than have lips, the hydra’s mouth is a sealed piece of intact skin that it tears open to gobble each meal.

There’s a small, tentacled freshwater animal called a hydra, whose mouth disappears every time it closes. I really mean that: it disappears. When your mouth closes, the two halves are still distinct.