Hydra (genus)
Videos
Hydra is a genus of small freshwater hydrozoans in the phylum Cnidaria. They are solitary, carnivorous jellyfish-like animals, native to the temperate and tropical regions. The genus was named by Linn
Hydra attached to a substrate
Cnidocyte
Videos
A cnidocyte is a type of cell containing a large secretory organelle called a cnidocyst, that can deliver a sting to other organisms as a way to subdue prey and defend against predators. A cnidocyte e
Nomarski micrograph of a ruthenium red-stained nematocyst from Aiptasia pallida, the pale anemone. The red dye stains the polyanionic venom proteins found inside the capsule of this partially-discharged nematocyst.
Nematocysts from Chironex fleckeri (400x magnification).