Hydra (/ ˈhaɪdrə / HY-drə) is a genus of small freshwater hydrozoans of the phylum Cnidaria.

3 天之前 · Hydra, genus of invertebrate freshwater animals of the class Hydrozoa (phylum Cnidaria). The body of such an organism consists of a thin, usually translucent tube that measures up to about 30 millimetres (1.2 inches) long but is capable of great contraction.

Hydra are a genus of small, fresh-water organisms that are classified under the phylum Cnidaria. In addition to being related to such organisms as jellyfish, they are characterized by their tiny, tube-shaped bodies that contain several tentacles on one end.

Hydra are inconspicuous freshwater relatives of corals, sea anemones and jellyfish. All are members of the phylum Cnidaria, characterized by radially symmetrical bodies, presence of stinging tentacles and a simple gut with only one opening (gastrovascular cavity).

Hydra is a genus of tiny fresh-water organisms that are classified under the phylum of Cnidaria. Hydra has a cylindrical, radially symmetric body from 2 to 20 mm in length. It is visible to the naked eyes when fully extended. Typically, hydras remain attached to some underwater objects, waving their tentacles slowly with the current.

2023年8月3日 · Hydra are inconspicuous freshwater relatives of corals, sea anemones, and jellyfish that are classified under the phylum Cnidaria, Class Hydrozoa, Order Anthomedusae/Anthoathecata, and Family Hydroidea. It is essentially a sedentary organism living attached to stones, pebbles, and water plants, but can get …

The phylum Cnidaria is a diverse group with cosmopolitan distribution. It includes the familiar hydras, the transparent jelly fishes, the beautiful and bright coloured sea anemones, a variety of corals and about 10,000 delightful aquatic species.

2010年11月23日 · What is Hydra? Hydra is a member of the animal phylum Cnidaria. This phylum includes corals, sea anemones and jellyfish. While most cnidarians are marine, Hydra is unusual in that it lives exclusively in fresh water. Hydra was first described by Antoni van Leeuwenhoek (1632–1723) in a letter he sent to the Royal Society on Christmas day, 1702.

2016年7月28日 · Hydra belongs to the phylum Cnidaria, a group of animals of the Hydrozoa classification; they are small animals that inhabit the fresh waters of tropical and temperate regions. Hydras are capable of regenerating, which renders them a great curiosity for biologists. Their death occurs due to old age. Their appearance does not change as age advances.

One of the smallest solitary polyps amongst the cnidarians is represented by Hydra. Almost all the hydras inhabit clear, transparent freshwater ponds and lakes ex­cepting Protohydra which is marine. Hydra owes its name from Greek mythology where the sea-serpent named Hydra had the inher­ent potentiality to regenerate its head, if extirpated.