Small animals
Hydra
Hydra (freshwater polyp)
A tiny freshwater relative of jellyfish and corals: a tube with a ring of tentacles, stuck to plants by its foot.
What to look for
- A tubular body with 4 to 12 thin tentacles around the mouth.
- Contracts to a small blob when disturbed and stretches out again slowly.
- Hydra viridissima is green from algae living in its cells; other species are brown or white. Buds grow on the side of the body.
Size in the field
Visible to the naked eye; best viewed at 20–40× with a stereo microscope.
Where to find it
On the underside of floating leaves and on stems in clean ponds.
Clips 0
No clip of this group is on the site yet. The description above is enough to check your own observation.