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Typhlosole
In Morphology (biology), biological morphology, a typhlosole is an internal fold of the Gut (anatomy), intestine or intestine inner wall. Typhlosoles occur in bivalve mollusks, lampreys and some annelids and echinoderms. In earthworms, it is a dorsal flap of the intestine that runs along most of its length, effectively forming a tube within a tube, and increasing the absorption area by that of its inner surface. Its function is to increase intestine surface area for more efficient absorption of digested nutrients. In different earthworm families, the typhlosole appears to have multiple origins. The Lumbricidae, for example, have a typhlosole which is an infolding of all layers of the intestine wall, whereas in some other families (e.g. Megascolecidae), it is an infolding of only the inner layer, and in many earthworms it is absent. In shipworms, the typhlosole is the organ where the lignin in wood are digested by Symbiosis, symbiont bacteria of the "Alteromonas, Alteromonas-like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphology (biology)
Morphology (from Ancient Greek μορφή (morphḗ) "form", and λόγος (lógos) "word, study, research") is the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, color, pattern, size), as well as the form and structure of internal parts like bones and organs, i.e., anatomy. This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of the overall structure of an organism or taxon and its component parts. History The etymology of the word "morphology" is from the Ancient Greek (), meaning "form", and (), meaning "word, study, research". While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Fried ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gut (anatomy)
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascular system. The GI tract contains all the major organs of the digestive system, in humans and other animals, including the esophagus, stomach, and intestines. Food taken in through the mouth is digested to extract nutrients and absorb energy, and the waste expelled at the anus as feces. ''Gastrointestinal'' is an adjective meaning of or pertaining to the stomach and intestines. Most animals have a "through-gut" or complete digestive tract. Exceptions are more primitive ones: sponges have small pores ( ostia) throughout their body for digestion and a larger dorsal pore ( osculum) for excretion, comb jellies have both a ventral mouth and dorsal anal pores, while cnidarians and acoels have a single pore for both digestion and excretion. The huma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bivalve
Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consisting of a hinged pair of half-bivalve shell, shells known as valve (mollusc), valves. As a group, bivalves have no head and lack some typical molluscan organs such as the radula and the odontophore. Their gills have evolved into ctenidium (mollusc), ctenidia, specialised organs for feeding and breathing. Common bivalves include clams, oysters, Cockle (bivalve), cockles, mussels, scallops, and numerous other family (biology), families that live in saltwater, as well as a number of families that live in freshwater. Majority of the class are benthic filter feeders that bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamprey
Lampreys (sometimes inaccurately called lamprey eels) are a group of Agnatha, jawless fish comprising the order (biology), order Petromyzontiformes , sole order in the Class (biology), class Petromyzontida. The adult lamprey is characterized by a toothed, funnel-like sucking mouth. The common name "lamprey" is probably derived from Latin , which may mean "stone licker" ( "to lick" + "stone"), though the etymology is uncertain. "Lamprey" is sometimes seen for the plural form. About 38 extant species of lampreys are known, with around seven known extinct species. They are classified in three families—two small families in the Southern Hemisphere (Geotriidae, Mordaciidae) and one large family in the Northern Hemisphere (Petromyzontidae). Genetic evidence suggests that lampreys are more closely related to hagfish, the only other living group of jawless fish, than they are to jawed vertebrates, forming the superclass Cyclostomi. The oldest fossils of stem-group lampreys are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annelid
The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments. The annelids are bilaterally symmetrical, triploblastic, coelomate, invertebrate organisms. They also have parapodia for locomotion. Most textbooks still use the traditional division into polychaetes (almost all marine), oligochaetes (which include earthworms) and leech-like species. Cladistic research since 1997 has radically changed this scheme, viewing leeches as a sub-group of oligochaetes and oligochaetes as a sub-group of polychaetes. In addition, the Pogonophora, Echiura and Sipuncula, previously regarded as separate phyla, are now regarded as sub-grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinoderm
An echinoderm () is any animal of the phylum Echinodermata (), which includes starfish, brittle stars, sea urchins, sand dollars and sea cucumbers, as well as the sessile sea lilies or "stone lilies". While bilaterally symmetrical as larvae, as adults echinoderms are recognisable by their usually five-pointed radial symmetry (pentamerous symmetry), and are found on the sea bed at every ocean depth from the intertidal zone to the abyssal zone. The phylum contains about 7,600 living species, making it the second-largest group of deuterostomes after the chordates, as well as the largest marine-only phylum. The first definitive echinoderms appeared near the start of the Cambrian. Echinoderms are important both ecologically and geologically. Ecologically, there are few other groupings so abundant in the deep sea, as well as shallower oceans. Most echinoderms are able to reproduce asexually and regenerate tissue, organs and limbs; in some cases, they can undergo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthworm
An earthworm is a soil-dwelling terrestrial invertebrate that belongs to the phylum Annelida. The term is the common name for the largest members of the class (or subclass, depending on the author) Oligochaeta. In classical systems, they were in the order of Opisthopora since the male pores opened posterior to the female pores, although the internal male segments are anterior to the female. Theoretical cladistic studies have placed them in the suborder Lumbricina of the order Haplotaxida, but this may change. Other slang names for earthworms include "dew-worm", "rainworm", "nightcrawler", and "angleworm" (from its use as angling hookbaits). Larger terrestrial earthworms are also called megadriles (which translates to "big worms") as opposed to the microdriles ("small worms") in the semiaquatic families Tubificidae, Lumbricidae and Enchytraeidae. The megadriles are characterized by a distinct clitellum (more extensive than that of microdriles) and a vascular system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumbricidae
The Lumbricidae are a family of earthworms. About 33 lumbricid species have become naturalized around the world, but the bulk of the species are in the Holarctic region, from Canada (e.g. ''Bimastos lawrenceae'' on Vancouver Island) and the United States (e.g. ''Eisenoides carolinensis'', '' E. lonnbergi'', and most '' Bimastos'' spp.) and throughout Eurasia to Japan (e.g. ''Eisenia japonica'', ''E. koreana'', and ''Helodrilus hachiojii''). An enigmatic species in Tasmania is '' Eophila eti''. Currently, 670 valid species and subspecies in about 42 genera are recognized. This family includes the majority of earthworm species well known in Europe and Asia. Genera The family consists of these genera: * '' Allolobophora'' Eisen, 1874 * '' Alpodinaridella'' Mršić, 1987 * '' Aporrectodea'' Orley, 1885 * '' Bimastos'' Moore, 1893 * '' Castellodrilus'' Qiu & Bouché, 1998 stat. nov. * '' Cataladrilus'' Qiu & Bouché, 1998 * '' Cernosvitovia'' Omodeo, 1956 * '' Creinella'' Mršić, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megascolecidae
Megascolecidae is a family of earthworms native to Madagascar, Australia, New Zealand, Asia, and North America. At up to 2 meters in length, their large size distinguishes the Megascolecidae from other earthworm families. They are an essential part of maintaining soil structure, minor carbon sequestration, and maintaining terrestrial ecosystems. Physiological features Different species of the Megascolecidae have different physiological features, but some similarities of physiological features can be found between species. The family contains relatively large individuals. The length of earthworms can vary from to . The number of spermathecal pores is normally paired, but multiples can be present in some species. The location of spermathecal pores and how they are positioned in different segmental locations is used in the identification of different megascolecidids. Earthworms ingest a variety of organic materials in the soil since they live in terrestrial environments. Earthwor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lignin
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are polymers made by cross-linking phenolic precursors. History Lignin was first mentioned in 1813 by the Swiss botanist A. P. de Candolle, who described it as a fibrous, tasteless material, insoluble in water and alcohol but soluble in weak alkaline solutions, and which can be precipitated from solution using acid. He named the substance "lignine", which is derived from the Latin word '' lignum'', meaning wood. It is one of the most abundant organic polymers on Earth, exceeded only by cellulose and chitin. Lignin constitutes 30% of terrestrial non-fossil organic carbon on Earth, and 20 to 35% of the dry mass of wood. Lignin is present in red algae, which suggest that the common ancestor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symbiosis
Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biological interaction, between two organisms of different species. The two organisms, termed symbionts, can for example be in Mutualism (biology), mutualistic, commensalism, commensalistic, or parasitism, parasitic relationships. In 1879, Heinrich Anton de Bary defined symbiosis as "the living together of unlike organisms". The term is sometimes more exclusively used in a restricted, mutualistic sense, where both symbionts contribute to each other's subsistence. This means that they benefit each other in some way. Symbiosis can be ''obligate'' (or ''obligative''), which means that one, or both of the organisms depend on each other for survival, or ''facultative'' (optional), when they can also subsist independently. Symbiosis is also classified by physical attachment. Symbionts forming a single body live ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
