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Bugulina Flabellata
''Bugulina flabellata'' is a species of bryozoan belonging to the family Bugulidae. It is found in shallow water in the northeastern Atlantic Ocean and the Mediterranean Sea. Description ''Bugulina flabellata'' is a colonial bryozoan forming small clumps up to high with a characteristic cone or fan-shape. The fronds have up to eight dichotomous branches with square tips. Each zooid bears two or three short spines. Colonies are dark buff when living and greyish when dried up. Distribution and habitat ''Bugulina flabellata'' has a wide distribution in shallow temperate waters in the northeastern Atlantic Ocean, the North Sea and the Mediterranean Sea. It has also been recorded off the coasts of Brazil, Mauritius and Australia. It grows on rock surfaces or the undersides of boulders, on stones and on shells, at depths down to about . Ecology Colonies of bryozoans grow by budding from a single zooid known as an ancestrula. ''Bugulina flabellata'' overwinters as a dormant holdfast o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Edward Gray
John Edward Gray, FRS (12 February 1800 – 7 March 1875) was a British zoologist. He was the elder brother of zoologist George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray (1766–1828). The same is used for a zoological name. Gray was keeper of zoology at the British Museum in London from 1840 until Christmas 1874, before the natural history holdings were split off to the Natural History Museum. He published several catalogues of the museum collections that included comprehensive discussions of animal groups and descriptions of new species. He improved the zoological collections to make them amongst the best in the world. Biography Gray was born in Walsall, but his family soon moved to London, where Gray studied medicine. He assisted his father in writing ''The Natural Arrangement of British Plants'' (1821). After being blackballed by the Linnean Society of London, Gray shifted his interest from botany to zoology. He began his zoologica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bryozoa
Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a lophophore, a "crown" of tentacles used for filter feeding. Most marine bryozoans live in tropical waters, but a few are found in oceanic trenches and polar waters. The bryozoans are classified as the marine bryozoans (Stenolaemata), freshwater bryozoans (Phylactolaemata), and mostly-marine bryozoans (Gymnolaemata), a few members of which prefer brackish water. 5,869living species are known. At least two genera are solitary (''Aethozooides'' and ''Monobryozoon''); the rest are colonial. The terms Polyzoa and Bryozoa were introduced in 1830 and 1831, respectively. Soon after it was named, another group of animals was discovered whose filtering mechanism looked similar, so it was included in Bryozoa until 1869, when the two groups were no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bugulidae
Bugulidae is a family of bryozoans belonging to the order Cheilostomatida. Genera The World Register of Marine Species lists the following genera:- *'' Beanodendria'' d'Hondt & Gordon, 1996 *'' Bicellariella'' Levinsen, 1909 *'' Bicellarina'' Levinsen, 1909 *'' Brettiella'' Gordon, 1984 *''Bugula'' Oken, 1815 *'' Bugularia'' Levinsen, 1909 *'' Bugulella'' Verrill, 1879 *'' Bugulina'' Gray, 1848 *'' Bugulopsis'' Verrill, 1880 *'' Calyptozoum'' Harmer, 1926 *'' Camptoplites'' Harmer, 1923 *'' Carolanna'' Gordon, 2021 *'' Caulibugula'' Verrill, 1900 *'' Cornucopina'' Levinsen, 1909 *'' Corynoporella'' Hincks, 1888 *'' Crisularia'' Gray, 1848 *'' Cuneiforma'' d'Hondt & Schopf, 1985 *'' Dendrobeania'' Levinsen, 1909 *'' Dimetopia'' Busk, 1852 *'' Falsibugulella'' Liu, 1984 *'' Farciminellopsis'' Silén, 1941 *''Halophila ''Halophila'' is a genus of seagrasses in the family ''Hydrocharitaceae'', the tape-grasses. It was described as a genus in 1806. The number of its contained spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichotomy
A dichotomy is a partition of a whole (or a set) into two parts (subsets). In other words, this couple of parts must be * jointly exhaustive: everything must belong to one part or the other, and * mutually exclusive: nothing can belong simultaneously to both parts. If there is a concept A, and it is split into parts B and not-B, then the parts form a dichotomy: they are mutually exclusive, since no part of B is contained in not-B and vice versa, and they are jointly exhaustive, since they cover all of A, and together again give A. Such a partition is also frequently called a bipartition. The two parts thus formed are complements. In logic, the partitions are opposites if there exists a proposition such that it holds over one and not the other. Treating continuous variables or multi categorical variables as binary variables is called dichotomization. The discretization error inherent in dichotomization is temporarily ignored for modeling purposes. Etymology The term '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zooid
A zooid or zoöid is a single animal that is part of a colonial animal. This lifestyle has been adopted by animals from separate unrelated taxa. Zooids are multicellular; their structure is similar to that of other solitary animals. The zooids can either be directly connected by tissue (e.g. corals, Catenulida, Siphonophorae, Pyrosome or Ectoprocta) or share a common exoskeleton (e.g. Bryozoa or Pterobranchia). The colonial organism as a whole is called a ''zoon'' , plural ''zoa'' (from Ancient Greek meaning animal; plural , ). Zooids can exhibit polymorphism. For instance, extant bryozoans may have zooids adapted for different functions, such as feeding, anchoring the colony to the substratum and for brooding embryos. However, fossil bryozoans are only known by the colony structures that the zooids formed during life. There are correlations between the size of some zooids and temperature. Variations in zooid size within colonies of fossils can be used as an indicator of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asexual Reproduction
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent and thus the newly created individual is genetically and physically similar to the parent or an exact clone of the parent. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea and eubacteria, bacteria. Many Eukaryote, eukaryotic organisms including plants, animals, and Fungus, fungi can also reproduce asexually. In vertebrates, the most common form of asexual reproduction is parthenogenesis, which is typically used as an alternative to sexual reproduction in times when reproductive opportunities are limited. Komodo dragons and some monitor lizards can also reproduce asexually. While all prokaryotes reproduce without the formation and fusion of gametes, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequential Hermaphroditism
Sequential hermaphroditism (called dichogamy in botany) is a type of hermaphroditism that occurs in many fish, gastropods, and plants. Sequential hermaphroditism occurs when the individual changes its sex at some point in its life. In particular, a sequential hermaphrodite produces eggs (female gametes) and sperm (male gametes) at different stages in life. Species that can undergo these changes from one sex to another do so as a normal event within their reproductive cycle that is usually cued by either social structure or the achievement of a certain age or size. In animals, the different types of change are male to female (protandry or protandrous hermaphroditism), female to male (protogyny or protogynous hermaphroditism), bidirectional (serial or bidirectional hermaphroditism). Both protogynous and protandrous hermaphroditism allow the organism to switch between functional male and functional female. Bidirectional hermaphrodites have the capacity for sex change in either directi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytoplankton
Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. Phytoplankton obtain their energy through photosynthesis, as do trees and other plants on land. This means phytoplankton must have light from the sun, so they live in the well-lit surface layers (euphotic zone) of oceans and lakes. In comparison with terrestrial plants, phytoplankton are distributed over a larger surface area, are exposed to less seasonal variation and have markedly faster turnover rates than trees (days versus decades). As a result, phytoplankton respond rapidly on a global scale to climate variations. Phytoplankton form the base of marine and freshwater food webs and are key players in the global carbon cycle. They account for about half of global photosynthetic activity and at least half of the oxygen production, despite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicellariella Ciliata
''Bicellariella ciliata'' is a species of bryozoan belonging to the family Bugulidae. It is found in shallow water on both sides of the Atlantic Ocean, the Mediterranean Sea and the Indo-Pacific region. Description ''Bicellariella ciliata'' is a colonial bryozoan and has an upright, branched habit, and forms small white, feathery clumps up to in height. The colony is fixed to the substrate by a narrow flexible base. The zooids grow on branches, facing alternately to left and right, and appearing as regular black spots to the naked eye. Each feeding zooid has a cone-shaped tube leading to a bean-shaped chamber; the lophophore has four to six long curved tentacles. Some zooids have a toothed "beak" which is used for defensive purposes. '' Bugulina flabellata'', ''Crisularia plumosa'' and ''Bugulina turbinata'' are other bryozoans of very similar morphology with which ''Bicellariella ciliata'' may be confused. ''Bicellariella ciliata'' can form a bryozoan "turf" with these three. D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bugulina Turbinata
''Bugulina turbinata'' is a species of bryozoan belonging to the family Bugulidae. It is found in shallow water in the northeastern Atlantic Ocean and the Mediterranean Sea. Description ''Bugulina turbinata'' is a colonial bryozoan that forms small bushy clumps, up to in height. These are orange or pale brown, and are attached to a hard substrate by an extension of the rhizoids at the base. Each frond has branchlets growing out in a spiral arrangement, each with two rows, widening to three to four rows, of zooids. The individual zooids are rectangular, about , with a short spine at each upper corner. The lophophore consists of thirteen tentacles and the avicularia is rounded and projects like a bird's head with a hooked beak, just below the spines. The conspicuous brood chambers are globular, and during the summer, yellow embryos can be seen developing inside. Ecology Developing embryos of ''Bugulina turbinata'' are retained within a brood chamber, and the larvae are only free ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Littoral Zone
The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal areas that are permanently submerged — known as the ''foreshore'' — and the terms are often used interchangeably. However, the geographical meaning of ''littoral zone'' extends well beyond the intertidal zone to include all neritic waters within the bounds of continental shelves. Etymology The word ''littoral'' may be used both as a noun and as an adjective. It derives from the Latin noun ''litus, litoris'', meaning "shore". (The doubled ''t'' is a late-medieval innovation, and the word is sometimes seen in the more classical-looking spelling ''litoral''.) Description The term has no single definition. What is regarded as the full extent of the littoral zone, and the way the littoral zone is divided into subregions, varies in different c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corynactis Viridis
''Corynactis viridis'', the jewel anemone, is a brightly coloured anthozoan similar in body form to a sea anemone or a scleractinian coral polyp, but in the order Corallimorpharia. It is found in the northeastern Atlantic Ocean and the Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ... and was first described by the Irish naturalist George Allman in 1846. Description The column of this species is smooth and roughly cylindrical, being slightly wider at the base and oral disc than in the centre. The base can grow to a diameter of about and is often ragged in outline; this is because the animal divides by longitudinal fission, and sometimes the two new individuals remain partially united. The individuals are usually found in dense aggregations, but each anima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
