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True Oyster
The Ostreidae, the true oysters, include most species of molluscs commonly consumed as oysters. Pearl oysters are not true oysters, and belong to the order Pteriida. Like scallops, true oysters have a central adductor muscle, which means the shell has a characteristic central scar marking its point of attachment. The shell tends to be irregular as a result of attaching to a substrate. Both oviparous (egg-bearing) and larviparous (larvae-bearing) species are known within Ostreidae. Both types are hermaphrodites. However, the larviparous species show a pattern of alternating sex within each individual, whereas the oviparous species are simultaneous hermaphrodites, producing either female or male gametes according to circumstances. Members of genus ''Ostrea'' generally live continually immersed and are quite flat, with roundish shells. They differ from most bivalves by having shells completely made up of calcite, but with internal muscle scars of aragonitic composition. They fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Oyster
The Pacific oyster, Japanese oyster, or Miyagi oyster (''Magallana gigas''), is an oyster native to the Pacific coast of Asia. It has become an introduced species in North America, Australia, Europe, and New Zealand. Etymology The genus ''Magallana'' is named for the Portuguese explorer Ferdinand Magellan and its specific epithet ''gígās'' is from the Greek for "giant". It was previously placed in the genus '' Crassostrea''; from the Latin ''crass'' meaning "thick", ''ostrea'' meaning "oyster", and ''Crassostrea gigas'' is considered by part of the scientific community to be the proper denomination as an accepted alternative in WoRMS, Description The shell of ''M. gigas'' varies widely with the environment where it is attached. Its large, rounded, radial folds are often extremely rough and sharp. The two valves of the shell are slightly different in size and shape, the right valve being moderately concave. Shell colour is variable, usually pale white or off-white. Mature spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zygote
A zygote (, ) is a eukaryotic cell formed by a fertilization event between two gametes. The zygote's genome is a combination of the DNA in each gamete, and contains all of the genetic information of a new individual organism. In multicellular organisms, the zygote is the earliest developmental stage. In humans and most other anisogamous organisms, a zygote is formed when an egg cell and sperm cell come together to create a new unique organism. In single-celled organisms, the zygote can divide asexually by mitosis to produce identical offspring. German zoologists Oscar and Richard Hertwig made some of the first discoveries on animal zygote formation in the late 19th century. Humans In human fertilization, a released ovum (a haploid secondary oocyte with replicate chromosome copies) and a haploid sperm cell (male gamete) combine to form a single diploid cell called the zygote. Once the single sperm fuses with the oocyte, the latter completes the division of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agerostrea
''Agerostrea'' is an extinct genus of fossil oysters, marine bivalve molluscs in the family Ostreidae, the true oysters. The genus ''Agerostrea'' is present in the Maastrichtian, the upper stage of the Late Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ... epoch, from 72.1 to 66 million years ago. Species Species within the genus ''Agerostrea'': *†''Agerostrea densicostata'' Sobetski 1982 *†''Agerostrea dentiformis'' Kassab 1998 *†''Agerostrea falcata'' Morton 1827 *†''Agerostrea kopajevitshi'' Sobetski 1982 *†''Agerostrea lunata'' Woods, 1912 *†''Agerostrea luppovi'' *†''Agerostrea mesenterica'' Morton, 1834 *†''Agerostrea monmouthensis'' *†''Agerostrea nasuta'' *†''Agerostrea negevensis'' Lewy 1996 *†''Agerostrea rouxi'' *†''Ageros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crassostrea Rhizophorae 000
''Crassostrea'' is a genus of true oysters (family Ostreidae) containing some of the most important oysters used for food. Some species in the genus have been moved to the genus ''Magallana''. Species Extant species Extant species include:Taxon list for ''Crassostrea'' World Register of Marine Species, accessed on 9 August 2017. * '' Crassostrea aequatorialis'' (d'Orbigny 1846) * '''' < ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seawater
Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has approximately of dissolved salts (predominantly sodium () and chloride () ions). The average density at the surface is 1.025 kg/L. Seawater is denser than both fresh water and pure water (density 1.0 kg/L at ) because the dissolved salts increase the mass by a larger proportion than the volume. The freezing point of seawater decreases as salt concentration increases. At typical salinity, it freezes at about . The coldest seawater still in the liquid state ever recorded was found in 2010, in a stream under an Antarctic glacier: the measured temperature was . Seawater pH is typically limited to a range between 7.5 and 8.4. However, there is no universally accepted reference pH-scale for seawater and the difference between measure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquaculture
Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lotus). Aquaculture involves cultivating freshwater, brackish water and saltwater populations under controlled or semi-natural conditions, and can be contrasted with commercial fishing, which is the harvesting of wild fish. Mariculture, commonly known as marine farming, refers specifically to aquaculture practiced in seawater habitats and lagoons, opposed to in freshwater aquaculture. Pisciculture is a type of aquaculture that consists of fish farming to obtain fish products as food. Aquaculture can also be defined as the breeding, growing, and harvesting of fish and other aquatic plants, also known as farming in water. It is an environmental source of food and commercial product which help to improve healthier habitats and used to re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trophic State Index
The Trophic State Index (TSI) is a classification system designed to rate water bodies based on the amount of biological productivity they sustain. Although the term "trophic index" is commonly applied to lakes, any surface water body may be indexed. The TSI of a water body is rated on a scale from zero to one hundred. Under the TSI scale, water bodies may be defined as: * oligotrophic (TSI 0–40, having the least amount of biological productivity, "good" water quality); * mesotrophic (TSI 40–60, having a moderate level of biological productivity, "fair" water quality); or * eutrophic to hypereutrophic (TSI 60–100, having the highest amount of biological productivity, "poor" water quality). The quantities of nitrogen, phosphorus, and other biologically useful nutrients are the primary determinants of a water body's TSI. Nutrients such as nitrogen and phosphorus tend to be limiting resources in standing water bodies, so increased concentrations tend to result in increased p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intertidal Zone
The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species of life, such as seastars, sea urchins, and many species of coral with regional differences in biodiversity. Sometimes it is referred to as the ''littoral zone'' or '' seashore'', although those can be defined as a wider region. The well-known area also includes steep rocky cliffs, sandy beaches, bogs or wetlands (e.g., vast mudflats). The area can be a narrow strip, as in Pacific islands that have only a narrow tidal range, or can include many meters of shoreline where shallow beach slopes interact with high tidal excursion. The peritidal zone is similar but somewhat wider, extending from above the highest tide level to below the lowest. Organisms in the intertidal zone are adapted to an environment of harsh extremes, living in water p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crassostrea
''Crassostrea'' is a genus of true oysters (family Ostreidae) containing some of the most important oysters used for food. Some species in the genus have been moved to the genus '' Magallana''. Species Extant species Extant species include:Taxon list for ''Crassostrea'' , accessed on 9 August 2017. * '' Crassostrea aequatorialis'' (d'Orbigny 1846) * '' Crassostrea angulata'' [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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