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Heteropsammia Cochlea
''Heteropsammia cochlea'', also known as walking dendro, is a species of small solitary coral in the family Dendrophylliidae that is native to the Indo-Pacific area. Description This small solitary free-living coral, not more than 2.5 cm across, is not fixed to the sea floor. It is composed of one or two corallites in the shape of a figure of eight when observed from top, making it easy to identify. The base in contact with the bottom is relatively circular, depending on the nature of the substrate it is either flat or slightly keeled. The base has an orifice that houses a commensal worm belonging to the family Aspidosiphonidae.LEON Virginie, PROUZET Anne, SCAPS Patrick, MITEL Cédric, in : DORIS, 21/3/2014 : Aspidosiphon muelleri Diesing, 1851, http://doris.ffessm.fr/fiche2.asp?fiche_numero=589 The overall color is yellowish, grayish or greenish. The polyp tentacles can be seen deployed, especially at night. Distribution & habitat The walking dendro is widespread througho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lorenz Spengler
Lorenz Spengler (22 September 1720 – 20 December 1807) was a Danish turner and naturalist. Born in Schaffhausen, Switzerland he arrived at Copenhagen in 1743 and became a tutor to Christian VI of Denmark and later Frederick V of Denmark in the art of turning. From 1771 he was head of the Royal Art Chamber (Det Kongelige Kunstkammer), a position he held until his death in 1807. Among his works is "''Beskrivelse og Oplysning over den hindindtil lidet udarbeidede Sloegt af mangeskallede Konchylier som Linnaeus har kaldet ''Lepas'' med tilfoiede nye og ubeskrevne Arter'' ", a treatise on shelled molluscs including many new species descriptions, of which six taxa are still valid. Spengler maintained a personal natural history collection, the ''Museo Spengleriano''. Spengler is commemorated in the scientific name of a species of Southeast Asian turtle, '' Geoemyda spengleri''.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Joh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamete
A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual that produces the larger type of gamete—called an ovum— and a male produces the smaller type—called a sperm. Sperm cells or spermatozoa are small and motile due to the flagellum, a tail-shaped structure that allows the cell to propel and move. In contrast, each egg cell or ovum is relatively large and non-motile. In short a gamete is an egg cell (female gamete) or a sperm (male gamete). In animals, ova mature in the ovaries of females and sperm develop in the testes of males. During fertilization, a spermatozoon and ovum unite to form a new diploid organism. Gametes carry half the genetic information of an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithophaga Lessepsiana
''Lithophaga'', the date mussels, are a genus of medium-sized marine bivalve molluscs in the family Mytilidae. Some of the earliest fossil ''Lithophaga'' shells have been found in Mesozoic rocks from the Alps and from Vancouver Island.Ludvigsen, Rolf & Beard, Graham. 1997. West Coast Fossils: A Guide to the Ancient Life of Vancouver Island. pg. 102Kleemann, K.H., 1994. Mytilid bivalve ''Lithophaga'' in Upper Triassic coral ''Pamiroseris'' from Zlambach Beds compared with Cretaceous ''Lithophaga alpina''. Facies 30, 151-154. The shells of species in this genus are long and narrow with parallel sides. The animals bore into stone or coral rock with the help of pallial gland secretions,"integument (mollusks)."Encyclopædia Britannica. 2009. Encyclopædia Britannica 2006 Ultimate Reference Suite DVD hence the systematic name ''Lithophaga'', which means "stone-eater". Their club-shaped borings are given the trace fossil name '' Gastrochaenolites''. Species Species within the genus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspidosiphon Muelleri
''Aspidosiphon muelleri'' is a species of unsegmented benthic marine worm in the phylum Sipuncula, the peanut worms. This worm is found in the eastern Atlantic Ocean, the Mediterranean Sea and in various locations in the Indo-Pacific region at depths down to about . Description ''Aspidosiphon muelleri'' has a cylindrical trunk and a narrower, cylindrical introvert at the front end which can retract back into the trunk. The oral disc is at the tip of the introvert; this has a terminal mouth and a cluster of ten to twelve short tentacles arranged in a crescent surrounding a nuchal organ. The introvert bears rings of tiny hooks at the front, and larger, more irregularly-placed hooks at the rear. At the front of the trunk is an anal shield and this acts as an operculum when the introvert is retracted. At the posterior of the trunk is the caudal shield; both it and the anal shield are rough and chitinised, with radial grooves and edged by wart-like papillae. This worm can grow to a l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sipuncula
The Sipuncula or Sipunculida (common names sipunculid worms or peanut worms) is a class containing about 162 species of unsegmented marine annelid worms. The name ''Sipuncula'' is from the genus name ''Sipunculus'', and comes from the Latin ''siphunculus'' meaning a "small tube". Sipuncula was once considered a phylum, but was demoted to a class of Annelida, based on recent molecular work. Sipunculans vary in size but most species are under in length. The body is divided into an unsegmented, bulbous trunk and a narrower, anterior section, called the "introvert", which can be retracted into the trunk. The mouth is at the tip of the introvert and is surrounded in most groups by a ring of short tentacles. With no hard parts, the body is flexible and mobile. Although found in a range of habitats throughout the world's oceans, the majority of species live in shallow water habitats, burrowing under the surface of sandy and muddy substrates. Others live under stones, in rock crevic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commensal Relationship
Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism (biology), mutualism, in which both organisms benefit from each other; Symbiosis#Amensalism, amensalism, where one is harmed while the other is unaffected; parasitism, where one is harmed and the other benefits, and parasitoidism, which is similar to parasitism but the parasitoid has a free-living state and instead of just harming its host, it eventually ends up killing it. The commensal (the species that benefits from the association) may obtain nutrients, shelter, support, or locomotion from the host species, which is substantially unaffected. The commensal relation is often between a larger host and a smaller commensal; the Host (biology), host organism is unmodified, whereas the commensal species may show great structural adaptation consistent with its habits, as in the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biotope
A biotope is an area of uniform environmental conditions providing a living place for a specific assemblage of plants and animals. ''Biotope'' is almost synonymous with the term "habitat", which is more commonly used in English-speaking countries. However, in some countries these two terms are distinguished: the subject of a habitat is a population, the subject of a biotope is a ''biocoenosis'' or "biological community". It is an English loanword derived from the German ''Biotop'', which in turn came from the Greek ''bios'' (meaning 'life') and ''topos'' ('place'). (The related word ''geotope'' has made its way into the English language by the same route, from the German '' Geotop''.) Ecology The concept of a biotope was first advocated by Ernst Haeckel (1834–1919), a German zoologist famous for the recapitulation theory. In his book ''General Morphology'' (1866), which defines the term "ecology", he stresses the importance of the concept of habitat as a prerequisite for an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planktonic
Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (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 whales. Marine plankton include bacteria, archaea, algae, protozoa and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in the freshwaters of lakes and rivers. Plankton are usually thought of as inhabiting water, but there are also airborne versions, the aeroplankton, that live part of their lives drifting in the atmosphere. These include plant spores, pollen and wind-scattered seeds, as well as microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air by sea spray. Though many planktonic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, colour, markings, or behavioural or cognitive traits. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', which is when both biological sexes are phenotypically indistinguishable from each other. Overview Ornamentation and coloration Common and easily identified types of dimorphism consist of ornamentation and coloration, though not always apparent. A difference in coloration of sexes within a given species is called sexual dichromatism, which is commonly seen in many species of birds and reptiles. Sexual selection leads to the exaggerated dim ... [...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] |
Sexual Reproduction
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes ( diploid). This is typical in animals, though the number of chromosome sets and how that number changes in sexual reproduction varies, especially among plants, fungi, and other eukaryotes. Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. Sexual reproduction also occurs in some unicellular eukaryotes. Sexual reproduction does not occur in prokaryotes, unicellular organisms without cell nuclei, such bacteria and archaea. However, some process in bacteria may be considered analogous to sexual reproduction in that they incorporate new genetic information, including bacterial conjugation, transformatio ... [...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] |
