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Withering Abalone Syndrome
Withering abalone syndrome is a disease of the abalone shellfish, primarily found in the black and red abalone species. First described in 1986, it is caused by the bacterium "''Candidatus'' Xenohaliotis californiensis", which attacks the lining of the abalone's digestive tract, inhibiting the production of digestive enzymes. To prevent starvation, the abalone consumes its own body mass, causing its characteristic muscular "foot" to wither and atrophy. This impairs the abalone's ability to adhere to rocks, making it far more vulnerable to predation. Withered abalone not eaten by predators typically starve. For reasons not yet well understood, some abalone can be infected with the bacterium without developing the disease. It is believed, however, that changes in environmental conditions, such as warmer than normal water temperatures, may induce the disease in abalone that already harbor the bacterium. For this reason, the spread of the bacterium could lead to further declines in abal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abalone
Abalone ( or ; via Spanish , from Rumsen ''aulón'') is a common name for any of a group of small to very large marine gastropod molluscs in the family (biology), family Haliotidae. Other common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...s are ear shells, sea ears, and, rarely, muttonfish or muttonshells in parts of Australia, ormer in United Kingdom, the UK, perlemoen in South Africa, and paua in New Zealand. Abalones are marine snails. Their taxonomy puts them in the family Haliotidae, which contains only one genus, ''Haliotis'', which once contained six subgenera. These subgenera have become alternate representations of ''Haliotis''. The number of species recognized worldwide ranges between 30 and 130 with over 230 species-level taxa described. The most comprehen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shellfish
Shellfish is a colloquial and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various species of molluscs, crustaceans, and echinoderms. Although most kinds of shellfish are harvested from saltwater environments, some are found in freshwater. In addition, a few species of land crabs are eaten, for example ''Cardisoma guanhumi'' in the Caribbean. Shellfish are among the most common food allergens. Despite the name, ''shellfish'' are not fish. Most shellfish are low on the food chain and eat a diet composed primarily of phytoplankton and zooplankton. Many varieties of shellfish, and crustaceans in particular, are actually closely related to insects and arachnids; crustaceans make up one of the main subphyla of the phylum Arthropoda. Molluscs include cephalopods (squids, octopuses, cuttlefish) and bivalves (clams, oysters), as well as gastropods (aquatic species such as whelks and winkles; land species such as snails and slugs). M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Abalone
''Haliotis cracherodii'', the black abalone, is a species of large edible sea snail, a marine gastropod mollusk in the family Haliotidae, the abalones. This species is relatively small compared with most of the other abalone species from the eastern Pacific, and it has a relatively smooth dark shell. This used to be the most abundant large marine mollusk on the west coast of North America, but now, because of overfishing and the withering syndrome, it has much declined in population and the IUCN Red List has classed the black abalone as Critically Endangered. Taxonomy ''Haliotis cracherodii'' comprises two subspecies: *''Haliotis cracherodii californiensis'' Swainson, 1822 (synonyms: ''Haliotis bonita'' Orcutt, 1900; ''Haliotis californiensis'' Swainson, 1822) *''Haliotis cracherodii cracherodii'' Leach, 1814 (synonyms: ''Haliotis expansa'' Talmadge, 1957; ''Haliotis holzneri'' Hemphil, 1907; ''Haliotis imperforata'' Dall, 1919; ''Haliotis lusus'' Finlay, 1927; ''Halioti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Abalone
''Haliotis rufescens'' (red abalone) is a species of very large edible sea snail in the family Haliotidae, the abalones, ormer shells or paua.Rosenberg, G. (2014)''Haliotis rufescens'' Swainson, 1822.Accessed through: World Register of Marine Species on 2014-10-28 It is distributed from British Columbia, Canada, to Baja California, Mexico.Cowles, D. (2005). Haliotis rufescens.'' Biological Department, Walla Walla University. Retrieved 25 February 2015.NatureServe. 2015''Haliotis rufescens''.NatureServe Explorer. Version 7.1. February 11, 2016. It is most common in the southern half of its range. Red abalone is the largest and most common abalone found in the northern part of the state of California. Habitat Red abalone live in rocky areas with kelp. They feed on the kelp species that grow in their home range, including giant kelp (''Macrocystis pyrifera''), feather boa kelp (''Egregia menziesii''), and bull kelp (''Nereocystis luetkeana''). Juveniles eat coralline algae, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterium
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationshi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Candidatus
In prokaryote nomenclature, ''Candidatus'' (Latin for candidate of Roman office) is used to name prokaryotic phyla that are well characterized but yet-uncultured. Contemporary sequencing approaches, such as 16S sequencing or metagenomics, provide much information about the analyzed organisms and thus allow to identify and characterize individual species. However, the majority of prokaryotic species remain uncultivable and hence inaccessible for further characterization in ''in vitro'' study. The recent discoveries of a multitude of candidate taxa has led to candidate phyla radiation expanding the tree of life through the new insights in bacterial diversity. Nomenclature History The initial International Code of Nomenclature of Prokaryotes as well as early revisions did not account for the possibility of identifying prokaryotes which were not yet cultivable. Therefore, the term ''Candidatus'' was proposed in the context of a conference of the International Committee on Systemati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digestive Tract
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 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 human gastrointestinal tract consists of the esophagus, stomach, and intestines, and is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzymes
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are Ribozyme, catalytic RNA molecules, called ribozymes. Enzymes' Chemical specificity, specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atrophy
Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations (which can destroy the gene to build up the organ), poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply to the target organ, excessive amount of apoptosis of cells, and disuse or lack of exercise or disease intrinsic to the tissue itself. In medical practice, hormonal and nerve inputs that maintain an organ or body part are said to have ''trophic'' effects. A diminished muscular trophic condition is designated as ''atrophy''. Atrophy is reduction in size of cell, organ or tissue, after attaining its normal mature growth. In contrast, hypoplasia is the reduction in the cellular numbers of an organ, or tissue that has not attained normal maturity. Atrophy is the general physiological process of reabsorption and breakdown of tissues, involving apoptosis. When it occurs as a result of disease or loss of trophic support because of other diseases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predation
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the host) and parasitoidism (which always does, eventually). It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators. Predators may actively search for or pursue prey or wait for it, often concealed. When prey is detected, the predator assesses whether to attack it. This may involve ambush or pursuit predation, sometimes after stalking the prey. If the attack is successful, the predator kills the prey, removes any inedible parts like the shell or spines, and eats it. Predators are adapted and often highly specialized for hunting, with acute senses such as vision, hearing, or smell. Many predatory animals, both vertebrate and inv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
El Niño
El Niño (; ; ) is the warm phase of the El Niño–Southern Oscillation (ENSO) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific (approximately between the International Date Line and 120°W), including the area off the Pacific coast of South America. The ENSO is the cycle of warm and cold sea surface temperature (SST) of the tropical central and eastern Pacific Ocean. El Niño is accompanied by high air pressure in the western Pacific and low air pressure in the eastern Pacific. El Niño phases are known to last close to four years; however, records demonstrate that the cycles have lasted between two and seven years. During the development of El Niño, rainfall develops between September–November. The cool phase of ENSO is es, La Niña, translation=The Girl, with SSTs in the eastern Pacific below average, and air pressure high in the eastern Pacific and low in the western Pacific. The ENSO cycle, including bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fishery
Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both in freshwater waterbodies (about 10% of all catch) and the oceans (about 90%). About 500 million people worldwide are economically dependent on fisheries. 171 million tonnes of fish were produced in 2016, but overfishing is an increasing problem — causing declines in some populations. Because of their economic and social importance, fisheries are governed by complex fisheries management practices and legal regimes that vary widely across countries. Historically, fisheries were treated with a " first-come, first-served " approach, but recent threats by human overfishing and environmental issues have required increased regulation of fisheries to prevent conflict and increase profitable economic activity on the fishery. Modern jurisdictio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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