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Bioturbation
Bioturbation is defined as the reworking of soils and sediments by animals or plants. It includes burrowing, ingestion, and defecation of sediment grains. Bioturbating activities have a profound effect on the environment and are thought to be a primary driver of biodiversity. The formal study of bioturbation began in the 1800s by Charles Darwin experimenting in his garden. The disruption of aquatic sediments and terrestrial soils through bioturbating activities provides significant ecosystem services. These include the alteration of nutrients in aquatic sediment and overlying water, shelter to other species in the form of burrows in terrestrial and water ecosystems, and soil production on land.Shaler, N. S., 1891, The origin and nature of soils, in Powell, J. W., ed., USGS 12th Annual report 1890–1891: Washington, D.C., Government Printing Office, p. 213-45. Bioturbators are deemed ecosystem engineers because they alter resource availability to other species through the physica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioirrigation
Bioirrigation refers to the process of benthos, benthic organisms flushing their burrows with overlying water. The exchange of dissolved substances between the porewater and overlying seawater that results is an important process in the context of the biogeochemistry of the oceans. Marine coastal ecosystems often have organisms that destabilize sediment. They change the physical state of the sediment. Thus improving the conditions for other organisms and themselves. These organisms often also cause bioturbation, which is commonly used interchangeably or in reference with bioirrigation. Bioirrigation works as two different processes. These processes are known as particle reworking and Ventilation (physiology), ventilation, which is the work of benthic macro-invertebrates (usually ones that burrow). This particle reworking and ventilation is caused by the organisms when they feed (faunal feeding), Defecation, defecate, burrow, and Respiration (physiology), respire. Bioirrigation i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walrus (Odobenus Rosmarus) Resting In A Crowd On Wahlbergøya, Svalbard (3)
The walrus (''Odobenus rosmarus'') is a large pinniped marine mammal with discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. It is the only extant species in the family Odobenidae and genus ''Odobenus''. This species is subdivided into two subspecies: the Atlantic walrus (''O. r. rosmarus''), which lives in the Atlantic Ocean, and the Pacific walrus (''O. r. divergens''), which lives in the Pacific Ocean. Adult walrus are characterised by prominent tusks and whiskers, and considerable bulk: adult males in the Pacific can weigh more than and, among pinnipeds, are exceeded in size only by the two species of elephant seals. Walrus live mostly in shallow waters above the continental shelves, spending significant amounts of their lives on the sea ice looking for benthic bivalve molluscs. Walruses are relatively long-lived, social animals, and are considered to be a "keystone species" in the Arctic marine regions. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walrus
The walrus (''Odobenus rosmarus'') is a large pinniped marine mammal with discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. It is the only extant species in the family Odobenidae and genus ''Odobenus''. This species is subdivided into two subspecies: the Atlantic walrus (''O. r. rosmarus''), which lives in the Atlantic Ocean, and the Pacific walrus (''O. r. divergens''), which lives in the Pacific Ocean. Adult walrus are characterised by prominent tusks and whiskers, and considerable bulk: adult males in the Pacific can weigh more than and, among pinnipeds, are exceeded in size only by the two species of elephant seals. Walrus live mostly in shallow waters above the continental shelves, spending significant amounts of their lives on the sea ice looking for benthic bivalve molluscs. Walruses are relatively long-lived, social animals, and are considered to be a " keystone species" in the Arctic marine regio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trace Fossil
A trace fossil, also called an ichnofossil (; ), is a fossil record of biological activity by lifeforms, but not the preserved remains of the organism itself. Trace fossils contrast with body fossils, which are the fossilized remains of parts of organisms' bodies, usually altered by later chemical activity or by mineralization. The study of such trace fossils is ichnology - the work of ichnologists. Trace fossils may consist of physical impressions made on or in the substrate by an organism. For example, burrows, borings ( bioerosion), urolites (erosion caused by evacuation of liquid wastes), footprints, feeding marks, and root cavities may all be trace fossils. The term in its broadest sense also includes the remains of other organic material produced by an organism; for example coprolites (fossilized droppings) or chemical markers (sedimentological structures produced by biological means; for example, the formation of stromatolites). However, most sedimentary struct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ghost Crab
Ghost crabs are semiterrestrial crabs of the subfamily Ocypodinae. They are common shore crabs in tropical and subtropical regions throughout the world, inhabiting deep burrows in the intertidal zone. They are generalist scavengers and predators of small animals. The name "ghost crab" derives from their nocturnality and their generally pale coloration. They are also sometimes called sand crabs, though the name refers to various other crabs that do not belong to the subfamily. Characteristics of the subfamily include one claw being larger than the other, thick and elongated eyestalks, and a box-like body. The differences in claw sizes, however, are not as marked as in male fiddler crabs. The subfamily includes 22 species in two genera. Taxonomy Ocypodinae is one of two subfamilies in the family Ocypodidae, the other being the fiddler crab subfamily, Ucinae. Both subfamilies have members in which one of the claw-bearing legs (the chelipeds) is much larger than the other. Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fiddler Crab
The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly larger than their minor claw, whilst females claws are both the same size. The name fiddler crab comes from the appearance of their small and large claw together, looking similar to a fiddle. A smaller number of ghost crab and mangrove crab species are also found in the family Ocypodidae. This entire group is composed of small crabs, the largest being ''Afruca tangeri'' which is slightly over two inches (5 cm) across. Fiddler crabs are found along sea beaches and brackish intertidal mud flats, lagoons, swamps, and various other types of brackish or salt-water wetlands. Whilst fiddler crabs are currently split into two subfamilies of Gelasiminae and Ucinae, there is still phylogenetic and taxonomical debate as to whether the movement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sipunculidae
Sipunculidae is a family of peanut worms. Species ''Phascolopsis'' * '' Phascolopsis gouldii'' (De Pourtalés, 1851) ''Siphonomecus'' * '' Siphonomecus multicinctus'' Fisher 1947 ''Siphonosoma'' * '' Siphonosoma arcassonense'' (Cuenot, 1902) * '' Siphonosoma australe'' (Keferstein, 1865) * '' Siphonosoma boholense'' (Selenka, de Man & Bülow, 1883) * '' Siphonosoma cumanense'' (Keferstein, 1867) * '' Siphonosoma dayi'' Stephen 1942 * '' Siphonosoma funafuti'' (Shipley, 1898) * '' Siphonosoma ingens'' (Fisher, 1952) * '' Siphonosoma mourense'' Satô, 1930 * '' Siphonosoma rotumanum'' (Shipley, 1898) * '' Siphonosoma vastum'' (Selenka & Bülow, 1883) ''Sipunculus'' * '' Sipunculus indicus'' Peters, 1850 * '' Sipunculus lomonossovi'' Murina 1968 * '' Sipunculus longipapillosus'' Murina 1968 * '' Sipunculus marcusi'' Ditadi 1976 * '' Sipunculus mundanus'' Selenka and Bulow, 1883 * '' Sipunculus norvegicus'' Danielssen, 1869 * '' Sipunculus nudus'' Linnaeus, 1766 * '' Sipunculus pha ... [...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 marine annelid worms, that have secondarily lost their segmentation. Sipuncula was once considered a phylum of unsegmented worms, 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 Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ... 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 thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nereis Diversicolor
''Hediste diversicolor'', commonly known as a ragworm, is a polychaete worm in the family Nereididae. It lives in a burrow in the sand or mud of beaches and estuaries in intertidal zones in the north Atlantic. This species is used in research, but its classification is in dispute; in the literature, it is often classified as ''Nereis diversicolor'' (O.F. Müller, 1776). Its specific name "diversicolor" refers to the fact that its colour changes from brown to green as the breeding season approaches. Description ''Hediste diversicolor'' can grow up to in length and may have from ninety to one hundred twenty segments when mature. The head has a pair of palps, two pairs of antennae, four pairs of tentacles and four eyes. Each body segment has a pair of bristly appendages known as parapodia which are used for swimming. There is a prominent blood vessel running along the dorsal surface of the animal. This ragworm is pale brown but changes to green as the gonads mature and the breeding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arenicola Marina 2010
''Arenicola'', also known as sandworms, is a genus of capitellid annelid worms comprising the lugworms and black lugs. ''A.cristata'' is the dominant warm-water lugworm on the shores of North America and Humboldt Bay, California. ''A. caroledna'' dominates in China and Japan while ''Arenicola marina'' is mostly found in Europe, up to Norway. ''Arenicola loveni'' is restricted to Southern Africa. Species The following species are recognised in the genus ''Arenicola'': *''Arenicola bombayensis'' Kewalramani et al * ''Arenicola brasiliensis'' Nonato, 1958 *''Arenicola caroledna'' Wells * ''Arenicola cristata'' Stimpson, 1856 * ''Arenicola defodiens'' Cadman & Nelson-Smith, 1993 * ''Arenicola glasselli'' Berkeley & Berkeley, 1939 * ''Arenicola loveni'' Kinberg, 1866 * ''Arenicola marina'' (Linnaeus, 1758) Life in a burrow A lugworm lives in a U-shaped burrow in sand. The U is made of an L-shaped gallery lined with mucus, from the toe of which a vertical unlined shaft runs up to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goby Fish With Shrimp
The Gobioidei are a suborder of percomorph fish. Many of these fishes are called gobies. It is by far the largest and most diverse order within the order Gobiiformes, and one of the most diverse groups of ray-finned fish in general. The suborder, which was previously considered a suborder of Perciformes, is made up of about 2,211 species that are divided between seven families. Phylogenetic relationships of the Gobioidei have been elucidated using molecular data. Gobies are primarily small species, often with large heads and tapered bodies, that live in marine water, but roughly 10% of these species inhabit fresh water. This order is composed chiefly of benthic or burrowing species; like many other benthic fishes, most gobioids do not have a gas bladder or any other means of controlling their buoyancy in water, so they must spend most of their time on or near the bottom. Traditionally most of the species called gobies have been classified in the order Perciformes as the suborder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
