Search results
Results From The WOW.Com Content Network
Hydra are diploblastic organisms, the body is composed of two embryonic cell layers; the ectoderm and the endoderm. The endoderm lines the gastrovascular cavity, which is a water-filled sac, this acts as a hydroskeleton and site for food digestion. They also have a simple nervous system that consist of a nerve net that covers the entire body. [5]
Hydramacin [5] is a bactericide recently discovered in Hydra; it protects the outer layer against infection. A single Hydra is composed of 50,000 to 100,000 cells which consist of three specific stem cell populations that create many different cell types.
Cnidarians range in size from a mere handful of cells for the parasitic myxozoans [31] through Hydra's length of 5–20 mm (1 ⁄ 4 – 3 ⁄ 4 in), [40] to the lion's mane jellyfish, which may exceed 2 m (6 ft 7 in) in diameter and 75 m (246 ft) in length. [41] Prey of cnidarians ranges from plankton to animals several times larger than ...
Although there are freshwater species, the great majority are marine (salt water) species, ranging from tidal zones to depths exceeding 8,800 m (5.5 mi). While most of the approximately 5,000–10,000 known species feed on bacteria and other food particles in the water, some host photosynthesizing micro-organisms as endosymbionts and these ...
Two branches from the tree-like colony are shown, with a feeding hydra (A) the tip of each twig. Buds at the base of the hydra (at B) eventually detach and grow into adult jellyfish (K) Scientific classification; Domain: Eukaryota: Kingdom: Animalia: Phylum: Cnidaria: Class: Hydrozoa: Order: Anthoathecata: Suborder: Filifera: Family: Oceaniidae
Siphonophorae (from Greek siphōn 'tube' + pherein 'to bear' [2]) is an order within Hydrozoa, which is a class of marine organisms within the phylum Cnidaria.According to the World Register of Marine Species, the order contains 175 species described thus far.
A few genera within this class live in freshwater habitats. Hydrozoans are related to jellyfish and corals , which also belong to the phylum Cnidaria . Some examples of hydrozoans are the freshwater jelly ( Craspedacusta sowerbyi ), freshwater polyps ( Hydra ), Obelia , Portuguese man o' war ( Physalia physalis ), chondrophores (Porpitidae ...
A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are roughly cylindrical in shape and elongated at the axis of the vase -shaped body. In solitary polyps, the aboral (opposite to oral) end is attached to the substrate by means of a disc-like holdfast called a pedal disc , while in colonies ...