Hydra is a widely distributed genus that can be used to demonstrate several important concepts and processes, as well as its own intriguing habitats. Hydra reproduces sexually and asexually by budding.
Brown Hydra (Hydra sp.): The larger and more durable of the types commonly available. This would be the choice for behavioral studies and predator/prey studies with Daphnia.
Green Hydra (Chlorohydra viridissima): Smaller and more delicate that brown hydra. Their green color is imparted by symbiotic green algae (usually Chlorella).
Mixed Hydra: Brown and green. Both types in a single container. Useful to illustrate variation between species.
This widely distributed genus can be used to demonstrate several important concepts and processes as well as its own intriguing habits. A freshwater cnidarian, Hydra is by far the most easily cultured and studied member of the phylum. Daphnia can be used as food to observe the prey capture behavior of Hydra which uses its nematocyst-laden tentacles to ensnare the prey and sting it into submission. Hydra reproduces both sexually, and asexually by budding—a process which is often ongoing in the cultures we supply.