|
Swiftia Rosea
''Swiftia rosea'' is a species of gorgonian-type octocoral in the family Plexauridae. Description Colonies of this sea fan are usually high. There is usually a single main stem with a few branches at an angle to the main stem but in a single plane. The polyps are in two rows on the thicker branches but near the tips they are closer together and more disordered. The colour of this sea fan is dark red. The polyps are colourless and cannot be retracted back into the branches. This sea fan resembles the closely related but rather less common ''Swiftia pallida ''Swiftia pallida'' is a species of gorgonian-type octocoral in the family Plexauridae sometimes known as the northern sea fan. At one time it was considered to be a subspecies of '' Swiftia rosea''. Description ''Swiftia pallida'' usually has a ...'', but is more densely branched. Distribution and habitat ''Swiftia rosea'' is native to the northeastern Atlantic Ocean including Scandinavia, Great Britain and Ireland. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octocorallia
Octocorallia (also known as Alcyonaria) is a class of Anthozoa comprising around 3,000 species of water-based organisms formed of colonial polyps with 8-fold symmetry. It includes the blue coral, soft corals, sea pens, and gorgonians (sea fans and sea whips) within three orders: Alcyonacea, Helioporacea, and Pennatulacea. These organisms have an internal skeleton secreted by mesoglea and polyps with eight tentacles and eight mesentaries. As with all Cnidarians these organisms have a complex life cycle including a motile phase when they are considered plankton and later characteristic sessile phase. Octocorals have existed at least since the Ordovician period, as shown by Maurits Lindström's findings in the 1970s, however recent work has shown a possible Cambrian origin. Biology Octocorals resemble the stony corals in general appearance and in the size of their polyps, but lack the distinctive stony skeleton. Also unlike the stony corals, each polyp has only eight tentacle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plexauridae
Plexauridae is a family of marine colonial octocorals in the phylum Cnidaria. Members of this family are found in shallow tropical and subtropical seas. Many species contain symbiotic photosynthetic protists called zooxanthellae. Characteristics The Plexauridae have a branching colony form and many are known as sea rods or sea fans. The axial core of the coral skeleton is horny and hollow, and contains no sclerites. This is covered by a layer of tissue called coenenchyme in which is embedded calcareous sclerites. The sclerites are very varied in form in the Plexauridae, and examination of their morphology is helpful in identifying the different species. The calyces in which the polyps sit are strengthened by further sclerites and have eight fine dividing walls called septa The Southeastern Pennsylvania Transportation Authority (SEPTA) is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus servic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyp (zoology)
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 of polyps it is connected to other polyps, either directly or indirectly. The oral end contains the mouth, and is surrounded by a circlet of tentacles. Classes In the class Anthozoa, comprising the sea anemones and corals, the individual is always a polyp; in the class Hydrozoa, however, the individual may be either a polyp or a medusa, with most species undergoing a life cycle with both a polyp stage and a medusa stage. In class Scyphozoa, the medusa stage is dominant, and the polyp stage may or may not be present, depending on the family. In those scyphozoans that have the larval planula metamorphose into a polyp, the polyp, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swiftia Pallida
''Swiftia pallida'' is a species of gorgonian-type octocoral in the family Plexauridae sometimes known as the northern sea fan. At one time it was considered to be a subspecies of '' Swiftia rosea''. Description ''Swiftia pallida'' usually has a single main stem arising from a narrow base and is sparsely branched. Its normal height is about but it can grow to . The polyps are mostly arranged alternately, but somewhat irregularly, on either side of the stem and branches. Each polyp is supported by eight spindle-shaped sclerites, spiny skeletal elements, which run from the stem or branch to the bases of the eight tentacles. In the north of its range, this species is usually white or pale grey, but in the Mediterranean it may be pink or red. This sea fan resembles pale varieties of the more common ''Swiftia rosea'' but is less bushy with fewer branches. Distribution and habitat ''Swiftia pallida'' is native to the northeast Atlantic Ocean, the Mediterranean Sea, the Bay of Biscay ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animals Described In 1887
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinoderms and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
