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Pile Worm
''Alitta succinea'' (known as the pile worm, clam worm or cinder worm) is a species of marine annelid in the family Nereididae (commonly known as ragworms or sandworms). It has been recorded throughout the North West Atlantic, as well as in the Gulf of Maine and South Africa. Description ''Alitta succinea'' has a long, elongated, cylindrical body divided into 160 segments, with four eyes, and two antennae on the front, resembling a pear shape with the posterior of its body being longer. The clam worm can reach up to in length, but most specimens are smaller than this. It is brown colored at the rear, and reddish-brown on the rest of its body. It has an identifiable head with four eyes, two sensory feelers or Pedipalp, palps, and many tentacles. The head consists of two segments: the anterior and posterior prostomium. The last body segment is known as the pygidium. The jaws of the clam worm are partly composed of zinc, making them lightweight compared to calcified jaws, whilst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heinrich Frey
Heinrich Frey (June 15, 1822 – January 17, 1890) was a German-born Swiss entomologist who studied Lepidoptera. Biography Heinrich Frey was born on June 15, 1822 in Frankfurt. He attended the gymnasium in Frankfurt until he was 16. Here he met Senator Carl Heinrich Georg von Heyden (1793–1866) who introduced him to entomology. He attended the University in Frankfurt, then travelled to Bonn, Berlin, and Göttingen. When he returned to Frankfurt am Main in 1839 von Heyden showed him Philipp Christoph Zeller's ''Attempt at a Classification of the Tineinae'' which had just appeared in Oken's ''Isis''. Until this publication, this group of moths had been hopelessly confused and Frey was impressed by Zeller's orderly arrangement. Returning to Göttingen in 1847 he first became a private tutor, then an “extraordinary” professor at the University. (An extraordinary professorial chair is one created by a university because of an application from an outside organisation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pygidium
The pygidium (: pygidia) is the posterior body part or shield of crustaceans and some other arthropods, such as insects and the extinct trilobites. In groups other than insects, it contains the anus and, in females, the ovipositor. It is composed of fused body segments, sometimes with a tail, and separated from thoracic segments by an articulation.Shultz, J.W. (1990). Evolutionary Morphology And Phylogeny of Arachnida. Cladistics 6: 1–38. Chelicerates In arachnids, the pygidium is formed by reduction of the last three opisthosomal segments to rings where there is no distinction between tergites and sternites. A pygidium is present in Palpigradi, Amblypygi, Uropygi, Schizomida, Ricinulei and in the extinct order Trigonotarbida. It is also present in early fossil representatives of horseshoe crabs. Trilobites In trilobites, the pygidium can range from extremely small (much smaller than the head, or cephalon) to larger than the cephalon. They can be smooth, as in order ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larva
A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase of their life cycle. A larva's appearance is generally very different from the adult form (''e.g.'' caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different. In the case of smaller primitive arachnids, the larval stage differs by having three instead of four pairs of legs. Larvae are frequently adapted to different environments than adults. For example, some larvae such as tadpoles live almost exclusively in aquatic environments but can live outside water as adult frogs. By living in a distinct environment, larvae may be given shelter from predators and reduce competition for resources with the adult population. Animals in the lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plankton
Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish, and baleen whales. Marine plankton include bacteria, archaea, algae, protozoa, microscopic fungi, and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. fresh water, Freshwater plankton are similar to marine plankton, but are found in lakes and rivers. Mostly, plankton just drift where currents take them, though some, like jellyfish, swim slowly but not fast enough to generally overcome the influence of currents. Although plankton are usually thought of as inhabiting water, there are also airborne versions that live part of their lives drifting in the at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semelparity And Iteroparity
Semelparity and iteroparity are two contrasting reproductive strategies available to living organisms. A species is considered ''semelparous'' if it is characterized by a single reproduction, reproductive episode before death, and ''iteroparous'' if it is characterized by multiple reproductive cycle, reproductive cycles over the course of its lifetime. ''Iteroparity'' can be further divided into continuous iteroparity (primates, including humans and chimpanzees) and seasonal iteroparity (birds, dogs, etc.) Some Botany, botanists use the parallel terms monocarpy and polycarpy. (See also plietesials.) In truly ''semelparous'' species, death after reproduction is part of an overall strategy that includes putting all available resources into maximizing reproduction, at the expense of future life (see #Trade-offs, § Trade-offs). In any ''iteroparous'' population there will be some individuals who happen to die after their first and before any second reproductive episode, but unless ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parapodium
In invertebrates, the term parapodium ( Gr. ''para'', beyond or beside + ''podia'', feet; : parapodia) refers to lateral outgrowths or protrusions from the body. Parapodia are predominantly found in annelids, where they are paired, unjointed lateral outgrowths that bear the chaetae. In several groups of sea snails and sea slugs, 'parapodium' refers to lateral fleshy protrusions. __TOC__ Annelid parapodia Most species of polychaete annelids have paired, fleshy parapodia which are segmentally arranged along the body axis. Parapodia vary greatly in size and form, reflecting a variety of functions, such as, anchorage, protection and locomotion. General description Parapodia in polychaetes can be uniramous (consisting of one lobe or ramus) but are usually biramous (two lobes or rami). In the latter case, the dorsal lobes are called notopodia and the ventral lobes neuropodia. Both neuropodia and notopodia may possess a bundle of chaetae (neurochaetae and notochaetae respectively ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epitoky
Epitoky is a process that occurs in many species of polychaete marine worms wherein a sexually immature worm (the atoke) is modified or transformed into a sexually mature worm (the epitoke). Epitokes are pelagic morphs capable of sexual reproduction. Unlike the immature form, which is typically benthic (lives on the bottom), epitokes are specialized for swimming as well as reproducing. The primary benefit to epitoky is increased chances of finding other members of the same species for reproduction. There are two methods in which epitoky can occur: schizogamy and epigamy. Schizogamy Many species go through schizogamy, where the atoke uses asexual reproduction to produce buds from its posterior end. Each bud develops into an epitoke which, once fully formed, will then break off from the atoke and become free-swimming. Many genetically identical epitokes are formed in this way, thus allowing a higher chance of finding a mate of the same species and subsequent passing of genes to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Phase
A lunar phase or Moon phase is the apparent shape of the Moon's directly sunlit portion as viewed from the Earth. Because the Moon is tidally locked with the Earth, the same hemisphere is always facing the Earth. In common usage, the four major phases are the new moon, the first quarter, the full moon and the last quarter; the four minor phases are waxing crescent, waxing gibbous, waning gibbous, and waning crescent. A lunar month is the time between successive recurrences of the same phase: due to the eccentricity of the Moon's orbit, this duration is not perfectly constant but averages about 29.5 days. The appearance of the Moon (its phase) gradually changes over a lunar month as the relative orbital positions of the Moon around Earth, and Earth around the Sun, shift. The visible side of the Moon is sunlit to varying extents, depending on the position of the Moon in its orbit, with the sunlit portion varying from 0% (at new moon) to nearly 100% (at full moon). Phenomenon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smithsonian Marine Station At Fort Pierce
The Smithsonian Marine Station at Fort Pierce is a research center that specializes in Floridian marine ecosystems and lifeforms. The research is focused mostly on the Indian River Lagoon The Indian River Lagoon is a grouping of three lagoons: the Mosquito Lagoon, the Banana River, and the Indian River, on the Atlantic Coast of Florida; one of the most biodiverse estuaries in the Northern Hemisphere and is home to more than 4, ... and also on the offshore waters of Florida's central and east coast. The first director of the station was Mary E. Rice, Mary Rice, who was also instrumental in its founding. The station is a part of the National Museum of Natural History, which is part of the Smithsonian Institution of Washington, D.C. Its purpose is to be a field station which will draw scientists and students from the Smithsonian and other institutions from around the world, in which they will investigate animals, plants, and physical processes of oceans and rivers. The informati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucus
Mucus (, ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both Serous fluid, serous and mucous cells. It is a viscous colloid containing inorganic ions, inorganic salts, antimicrobial enzymes (such as lysozymes), Antibody, immunoglobulins (especially Immunoglobulin A, IgA), and glycoproteins such as lactoferrin and mucins, which are produced by goblet cells in the mucous membranes and submucosal glands. Mucus covers the Epithelium, epithelial cells that interact with outside environment, serves to protect the linings of the respiratory system, respiratory, Digestion#Digestive system, digestive, and Genitourinary system, urogenital systems, and structures in the Visual system, visual and auditory systems from pathogenic Fungus, fungi, bacteria and viruses. Most of the mucus in the body is produced in the gastrointestinal tract. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polychaete
Polychaeta () is a paraphyletic class of generally marine Annelid, annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. More than 10,000 species are described in this class. Common representatives include the lugworm (''Arenicola marina'') and the Alitta virens, sandworm or Alitta succinea, clam worm ''Alitta''. Polychaetes as a class are robust and widespread, with species that live in the coldest ocean temperatures of the abyssal plain, to forms which tolerate the extremely high temperatures near hydrothermal vents. Polychaetes occur throughout the Earth's oceans at all depths, from forms that live as plankton near the surface, to a 2- to 3-cm specimen (still unclassified) observed by the robot ocean probe Nereus (underwater vehicle), ''Nereus'' at the bottom of the Challenger Deep, the deepest known spot in the Earth's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustacean
Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthropods including decapods (shrimps, prawns, crabs, lobsters and crayfish), seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, opossum shrimps, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods (insects and entognathans) emerged deep in the Crustacean group, with the completed pan-group referred to as Pancrustacea. The three classes Cephalocarida, Branchiopoda and Remipedia are more closely related to the hexapods than they are to any of the other crustaceans ( oligostracans and multicrustaceans). The 67,000 described species range in size from '' Stygotantulus stocki'' at , to the Japanese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
