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Operculum (animal)
An operculum is an anatomical feature, a stiff structure resembling a lid or a small door that opens and closes, and thus controls contact between the outside world and an internal part of an animal. Examples include: * An operculum (gastropod), a single lid that (in its most complete form) closes the aperture of the shell when the animal is retracted, and thus protects the internal soft parts of the animal that are not completely covered by the shell. The operculum lies on the top rear part of the foot. When the foot is retracted, the operculum is rotated 180° and closes the shell. * An operculum (fish), a flap that covers the gills in bony fishes and chimaeras. * The cover that rapidly opens a cnida of a cnidarian such as a jellyfish or a sea anemone. The lid may be a single hinged flap or three hinged flaps arranged like slices of pie. * In insects, the operculum is the name for one or more lids covering the tympanal cavity. A subgenital operculum is exhibited in stick ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rapana Black Sea 2008 G1
''Rapana'' is a genus of large predatory sea snails, marine gastropod mollusks in the family Muricidae, the rock snails. Description The shell of ''Rapana'' has a large body whorl, a correspondingly large aperture and a low spire. The surface is covered in a thin calcitic layer. The rachidian teeth have three large cusps but no marginal cusps, instead the outer sides of the lateral cusps on the rachidian have a comb-like region. Species Species within the genus ''Rapana'' include: * '' Rapana bezoar'' (Linnaeus, 1767) * '' Rapana rapiformis'' (Born, 1778) * ''Rapana venosa'' (Valenciennes, 1846)Rapana venosa (Valenciennes, 1846) Zugriff über |
Cnida
A cnidocyte (also known as a cnidoblast) is a type of Cell (biology), cell containing a large secretory organelle called a ''cnidocyst'', that can deliver a sting to other organisms as a way to capture prey and defend against predators. A cnidocyte explosively ejects the toxin-containing cnidocyst which is responsible for the stings delivered by a cnidarian. The presence of this cell defines the phylum Cnidaria, which also includes the corals, sea anemones, Hydra (genus), hydrae, and jellyfish. Cnidocytes are single-use cells that need to be continuously replaced. Structure and function Each cnidocyte contains an organelle called a cnidocyst, which consists of a bulb-shaped capsule and a hollow, coiled tubule that is contained within. Immature cnidocytes are referred to as cnidoblasts or nematoblasts. The externally oriented side of the cell has a hair-like trigger called a cnidocil, a mechano-chemical receptor. When the trigger is activated, the tubule shaft of the cnidocyst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sven Bradler
Sven is a Scandinavian masculine first name. In Old Norse the meaning was "young man" or "servant" and the original Old Norse spelling was ''sveinn''. Variants such as '' Svend'' are found in Danish and Norwegian. Another variant, ''Svein'' is used only in the Low Countries and German-speaking countries, and is cognate with the English surname '' Swain''. In medieval Swedish, ''sven'' or ''sven av vapen'' "sven of arms", is a term for squire. The female equivalent, Svenja, though seemingly Dutch and Scandinavian, is not common anywhere outside of German-speaking countries. Sven can also be spelled with a "w" - Swen - but is pronounced as Sven. The Icelandic version is ''Sveinn'' (); the Faroese version is Sveinur (). Entertainment and music * Sven Einar Englund (1916–1999), Finnish composer * Sven Epiney (born 1972), Swiss television, radio host and editor * Sven Grünberg (born 1956), Estonian synthesizer and progressive rock composer and musician * Sven August K� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthoptera
Orthoptera () is an order of insects that comprises the grasshoppers, locusts, and crickets, including closely related insects, such as the bush crickets or katydids and wētā. The order is subdivided into two suborders: Caelifera – grasshoppers, locusts, and close relatives; and Ensifera – crickets and close relatives. More than 20,000 species are distributed worldwide. The insects in the order have incomplete metamorphosis, and produce sound (known as a " stridulation") by rubbing their wings against each other or their legs, the wings or legs containing rows of corrugated bumps. The tympanum, or ear, is located in the front tibia in crickets, mole crickets, and bush crickets or katydids, and on the first abdominal segment in the grasshoppers and locusts. These organisms use vibrations to locate other individuals. Grasshoppers and other orthopterans are able to fold their wings (i.e. they are members of Neoptera). Etymology The name is derived from the Gree ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stick Insects
The Phasmatodea (also known as Phasmida or Phasmatoptera) are an order of insects whose members are variously known as stick insects, stick bugs, walkingsticks, stick animals, or bug sticks. They are also occasionally referred to as Devil's darning needles, although this name is shared by both dragonflies and crane flies. They can be generally referred to as phasmatodeans, phasmids, or ghost insects, with phasmids in the family Phylliidae called leaf insects, leaf-bugs, walking leaves, or bug leaves. The group's name is derived from the Ancient Greek ', meaning an apparition or phantom, referring to their resemblance to vegetation while in fact being animals. Their natural camouflage makes them difficult for predators to detect; still, many species have one of several secondary lines of defense in the form of startle displays, spines or toxic secretions. Stick insects from the genera '' Phryganistria'', '' Ctenomorpha'', and ''Phobaeticus'' include the world's longest inse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Anemone
Sea anemones ( ) are a group of predation, predatory marine invertebrates constituting the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and ''hydra (genus), Hydra''. Unlike jellyfish, sea anemones do not have a Jellyfish#Life history and behavior, medusa stage in their life cycle. A typical sea anemone is a single polyp (zoology), polyp attached to a hard surface by its base, but some species live in soft sediment, and a few float near the surface of the water. The polyp has a columnar trunk topped by an oral disc with a ring of tentacles and a central mouth. The tentacles can be retracted inside the body cavity or expanded to catch passing prey. They are armed with cnidocytes (stinging cells). In many specie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jellyfish
Jellyfish, also known as sea jellies or simply jellies, are the #Life cycle, medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals, although a few are anchored to the seabed by stalks rather than being motile. They are made of an umbrella-shaped main body made of mesoglea, known as the ''bell'', and a collection of trailing tentacles on the underside. Via pulsating contractions, the bell can provide propulsion for animal locomotion, locomotion through open water. The tentacles are armed with cnidocyte, stinging cells and may be used to capture prey or to defend against predators. Jellyfish have a complex biological life cycle, life cycle, and the medusa is normally the sexual phase, which produces planula larvae. These then disperse widely and enter a sedentary #Life cycle, polyp phase which may include asexual budding before reaching sexual maturity. Jellyfish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cnidaria
Cnidaria ( ) is a phylum under kingdom Animalia containing over 11,000 species of aquatic invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, sea anemones, corals and some of the smallest marine parasites. Their distinguishing features are an uncentralized 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 (biology), cell thick. Cnidarians are also some of the few animals that can reproduce both sexually and asexually. Cnidarians mostly have two basic body forms: swimming medusa (biology), medusae and sessility (motility), sessile polyp (zoology), polyps, both of which are radially symmetrical with mou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chimaera
Chimaeras are Chondrichthyes, cartilaginous fish in the order (biology), order Chimaeriformes (), known informally as ghost sharks, rat fish (not to be confused with rattails), spookfish, or rabbit fish; the last two names are also applied to Barreleye, Opisthoproctidae and Rabbitfish, Siganidae, respectively. At one time a "diverse and abundant" group (based on the fossil record), their closest living relatives are sharks and ray (fish), rays, though their last common ancestor with them lived nearly 400 million years ago. Living species (aside from plough-nose chimaeras) are largely confined to deep water. Anatomy Chimaeras are soft-bodied, shark-like fish with bulky heads and long, tapered tails; measured from the tail, they can grow up to in length. Like other members of the class Chondrichthyes, chimaera skeletons are entirely cartilaginous, or composed of cartilage. Males use forehead denticles to grasp a female by a fin during copulation. The Branchial arch, gill arche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydra Nematocyst Firing 01
Hydra generally refers to: * Lernaean Hydra, a many-headed serpent in Greek mythology * ''Hydra'' (genus), a genus of simple freshwater animals belonging to the phylum Cnidaria Hydra or The Hydra may also refer to: Astronomy * Hydra (constellation) * Hydra (moon), a satellite of Pluto Computing * Hydra (chess), a chess computer * Hydra (digital repository), an open-source digital repository software product later renamed Samvera * Hydra (operating system), an early, discontinued, capability-based, object-oriented microkernel * Hydra (software), a parallelized network login cracker built in various operating systems * Hydra (specification), a specification for REST APIs * Hydra 100, a multi-GPU hardware solution * HYDRA Game Development Kit, a development system by André LaMothe * Razer Hydra, a game controller * NEC HYDRAstor, a storage system Fictional entities * Hydra (comics), a fictional organization in the Marvel Universe ** Hydra (Marvel Cinematic Universe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bony Fish
Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes (cartilaginous fish) and the extinct placoderms and acanthodians, which have endoskeletons primarily composed of cartilage. The vast majority of extant taxon, extant fish are members of Osteichthyes, being an extremely diverse and abundant group consisting of 45 order (biology), orders, over 435 family (biology), families and 28,000 species. The group is divided into two main clades, the ray-finned fish (Actinopterygii, which makes up the vast majority of extant fish) and the lobe-finned fish (Sarcopterygii, which gave rise to all land vertebrates, i.e. tetrapods). The oldest known fossils of bony fish are about 425 million years old from the late Silurian, which are also transitional fossils showing a dentition, tooth pattern th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gills
A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are kept moist. The microscopic structure of a gill presents a large surface area to the external environment. Branchia (: branchiae) is the zoologists' name for gills (from Ancient Greek ). With the exception of some aquatic insects, the filaments and lamellae (folds) contain blood or coelomic fluid, from which gases are exchanged through the thin walls. The blood carries oxygen to other parts of the body. Carbon dioxide passes from the blood through the thin gill tissue into the water. Gills or gill-like organs, located in different parts of the body, are found in various groups of aquatic animals, including molluscs, crustaceans, insects, fish, and amphibians. Semiterrestrial marine animals such as crabs and mudskippers have gill chamber ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
