| Hydranthea | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: | Hydrozoa |
| Order: | Leptothecata |
| Family: | Lovenellidae |
| Genus: | Hydranthea Hincks, 1868 |
Hydranthea is a genus of cnidarians belonging to the family Lovenellidae. [1] Like other Hydrozoans they are colonial. They have hydrorhiza connected to tubular stolons attaching them to other objects, [2] like algae, kelp, rocks and crabs.
Hydranthea have small smooth hydrophores placed irregularly along their hydrorhiza, of variable length - though they tend to be shorter. They have elongated polyps along their stems. [3] Their bodies are pale gold in color, with a thin white band below the hypostome, an appendage on their mouth. [4] Their tentacles, of which they have 30 per whorl, are long and colorless and connected to each other at their bases by an intertentacular web. They have around two to three Nematocysts between each set of tentacles on this web.
Hydranthea have oval gonophores, a reproductive structure, on their hydrorhiza. They are dieoecious, with usually only one sex, male or female, present within a single colony. [5]
Hydranthea are active and capable of stretching their tentacles, tending to bend to touch the substrate they are rooted in when disturbed. [6]
Species: [7]
A fourth species is in dispute, previously classified by some databases as Hydranthea phialiformis . [8] Latest databases accept the species as Hydractinia phialiformis [9] (Antsulevich, 1983), a separate genus from Hydranthea.
There was also a lack of consensus on the specific family Hydranthea belongs to. Several accounts noted it as belonging to the Haleciidae, however recent research has moved Hydranthea to Lovenellidae. [10]
The species of this genus are found in oceans surrounding Europe, [11] Japan and Australia. [12] There have been sightings of Hydranthea margarica found in Scottish waters near Sanda Island, Argyll. [13] This species has also been found in the Indian Ocean, south of Australia and the Seychelles, [12] though the latter is hypothesized to potentially be a different species due to the lack of nematocysts on the samples found there. [12] Species found in the Mediterranean Sea, notably Hydranthea aloysii, have been cited with high confidence (≤95%) to be extinct, or at least extremely rare, due to their lack of sightings in recent scientific literature about the region. [14]
Cnidaria is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in fresh water and marine environments, including jellyfish, hydroids, sea anemones, corals and some of the smallest marine parasites. Their distinguishing features are a decentralized nervous system distributed throughout a gelatinous body and the presence of cnidocytes or cnidoblasts, specialized cells with ejectable flagella used mainly for envenomation and capturing prey. Their bodies consist of mesoglea, a non-living, jelly-like substance, sandwiched between two layers of epithelium that are mostly one cell thick. Cnidarians are also some of the only animals that can reproduce both sexually and asexually.
Hydra is a genus of small freshwater hydrozoans of the phylum Cnidaria. They are native to the temperate and tropical regions. The genus was named by Linnaeus in 1758 after the Hydra, which was the many-headed beast of myth defeated by Heracles, as when the animal has a part severed, it will regenerate much like the mythical hydra’s heads. Biologists are especially interested in Hydra because of their regenerative ability; they do not appear to die of old age, or to age at all.
Hydrozoa is a taxonomic class of individually very small, predatory animals, some solitary and some colonial, most of which inhabit saline water. The colonies of the colonial species can be large, and in some cases the specialized individual animals cannot survive outside the colony. A few genera within this class live in freshwater habitats. Hydrozoans are related to jellyfish and corals and belong to the phylum Cnidaria.
Siphonophorae 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.
Medusozoa is a clade in the phylum Cnidaria, and is often considered a subphylum. It includes the classes Hydrozoa, Scyphozoa, Staurozoa and Cubozoa, and possibly the parasitic Polypodiozoa. Medusozoans are distinguished by having a medusa stage in their often complex life cycle, a medusa typically being an umbrella-shaped body with stinging tentacles around the edge. With the exception of some Hydrozoa, all are called jellyfish in their free-swimming medusa phase.
Anthoathecata, or the athecate hydroids, are an order of hydrozoans belonging to the phylum Cnidaria. A profusion of alternate scientific names exists for this long-known and heavily discussed group. It has also been called Gymnoblastea and, Anthomedusa, Athecata, Hydromedusa, and Stylasterina. There are about 1,200 species worldwide.
Lovenellidae is a family of hydrozoans. Their hydroids live together in upright stolonal or sympodial colonies, and their gonophores are pedunculate free-roaming medusae. The relationships of this fairly small but distinctive radiation to other members of the order Leptothecata are not well understood at present.
Haleciidae is a family of hydrozoans. Their hydroid colonies emerge from a creeping hydrorhiza and usually form upright branching colonies, although some species' colonies are stolonal. Their gonophores are typically sporosacs, growing singly or bunched into a glomulus. They remain attached to the hydroids or break off to be passively drifted away; in a few, the gonophores are naked.
Bougainvillia aberrans is a marine invertebrate, a species of hydroid in the suborder Anthomedusae. It was first described by Dale Calder in 1993. They have four radical clusters of marginal tentacles. Bougainvillia aberrans is found in Bermuda in the western North Atlantic Ocean.
Jean Bouillon was a Belgian marine biologist and expert on Hydrozoa.
Filifera is a suborder of hydrozoans in the order Anthoathecata. They are found in marine, brackish and freshwater habitats.
Aegina rosea is a species of hydrozoan of the family Aeginidae. It is one of two species in the genus Aegina, which was believed to be monotypic, until molecular phylogenetic analysis revealed that Aegina rosea was a second species.
Naomi Adeline Helen Millard, née Bokenham was a South African biologist, one of the founders of the Zoological Society of South Africa and the Zoologica Africana Journal.
Pouebo symmetricauda is a species of fly belonging to the family Dolichopodidae. It is the only member of the genus Pouebo, and was described from New Caledonia.
Zancleidae is a family of cnidarians belonging to the order Anthoathecata.
The epibiotic hydroid is a benthic species within the Cnidaria phylum which is distributed throughout the Western Atlantic Ocean.
Tima nigroannulata, commonly known as the elegant jellyfish, is a recently discovered colonial hydrozoa found on the Pacific coast of Japan.
Symplectoscyphus is a genus of cnidarians. It belongs to the Symplectoscyphidae family.
Hybocodon prolifer is a species of Hydrozoa belonging to the family Tubulariidae.
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