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Halophila Decipiens
''Halophila decipiens'', commonly known as Caribbean seagrass or paddle grass, is a seagrass in the family Hydrocharitaceae. It grows underwater on sandy or muddy sea floors in shallow parts of tropical seas. Description ''Halophila'' is the only genus of seagrass that lacks basal sheaths on the leaf stems. ''Halophila decipiens'' has thin rhizomes that run along near the surface of sand or mud, with a root at each node to anchor the plant in place. The almost stemless leaves grow in pairs from the nodes with a pair of scales at their base. The leaves are paddle-shaped and have a finely serrated margin and are up to long and wide. Male and female flowers are found on the same spathe and a female flower can produce about 30 seeds. Flowering seems to be stimulated by a rise in water temperature above a certain threshold rather than day length. The plant is an annual. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Hansen Ostenfeld
Carl Emil Hansen Ostenfeld (born Carl Emil Ostenfeld-Hansen) (3 August 1873 – 16 January 1931) was a Danish systematic botanist. He graduated from the University of Copenhagen under professor Eugenius Warming. He was a keeper at the Botanical Museum 1900–1918, when he became professor of botany at the Royal Veterinary and Agricultural University. In 1923, by the early retirement of Raunkiær's, Ostenfeld became professor of botany at the University of Copenhagen and director of the Copenhagen Botanical Garden, both positions held until his death in 1931. He was a member of the Royal Danish Academy of Sciences and Letters and served on the board of directors of the Carlsberg Foundation. Ostenfeld is known as an explorer of the Danish flora, including marine plankton, as well as the flora of Western Australia. Ostenfeld participated in the Ingolf expedition (1885-86) to the waters around Iceland and Greenland, and in 1911 in the International Phytogeographic Excursion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salinity
Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal to ‰). Salinity is an important factor in determining many aspects of the chemistry of natural waters and of biological processes within it, and is a state function, thermodynamic state variable that, along with temperature and pressure, governs physical characteristics like the density and heat capacity of the water. A contour line of constant salinity is called an ''isohaline'', or sometimes ''isohale''. Definitions Salinity in rivers, lakes, and the ocean is conceptually simple, but technically challenging to define and measure precisely. Conceptually the salinity is the quantity of dissolved salt content of the water. Salts are compounds like sodium chloride, magnesium sulfate, potassium nitrate, and sodium bicarbo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthuridae
Acanthuridae are the family of surgeonfishes, tangs, and unicornfishes. The family includes about 86 extant species of marine fish living in tropical seas, usually around coral reefs. Many of the species are brightly colored and popular in aquaria. Morphology The distinctive characteristic of the family is that they have scalpel-like modified scales, one or more on either side of the peduncle of the tail. The spines are dangerously sharp and may seriously injure anyone who carelessly handles such a fish. The dorsal, anal, and caudal fins are large, extending for most of the length of the body. The mouths are small and have a single row of teeth adapted to grazing on algae. Surgeonfishes sometimes feed as solitary individuals, but they often travel and feed in schools. Feeding in schools may be a mechanism for overwhelming the highly aggressive defense responses of small territorial damselfishes that vigorously guard small patches of algae on coral reefs. Most species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parrotfish
Parrotfishes are a group of about 90 fish species regarded as a family (Scaridae), or a subfamily (Scarinae) of the wrasses. With about 95 species, this group's largest species richness is in the Indo-Pacific. They are found in coral reefs, rocky coasts, and seagrass beds, and can play a significant role in bioerosion. Description Parrotfish are named for their dentition, which is distinct from other fish, including other labrids. Their numerous teeth are arranged in a tightly packed mosaic on the external surface of their jaw bones, forming a parrot-like beak with which they rasp algae from coral and other rocky substrates (which contributes to the process of bioerosion). Maximum sizes vary within the family, with the majority of species reaching in length. However, a few species reach lengths in excess of , and the green humphead parrotfish can reach up to . The smallest species is the bluelip parrotfish (''Cryptotomus roseus''), which has a maximum size of . Mucus Some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Turtle
Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhead, Kemp's ridley, and olive ridley sea turtles. All six of the sea turtle species present in US waters (all of those listed above except the flatback) are listed as endangered and/or threatened under the Endangered Species Act. The seventh sea turtle species is the flatback, which exists in the waters of Australia, Papua New Guinea and Indonesia. Sea turtles can be separated into the categories of hard-shelled ( cheloniid) and leathery-shelled ( dermochelyid).Wyneken, J. 2001. The Anatomy of Sea Turtles. U.S Department of Commerce NOAA Technical Memorandum NMFS-SEFSC-470, 1-172 pp. There is only one dermochelyid species which is the leatherback sea turtle. Description For each of the seven types of sea turtles, females and males are t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Urchin
Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) of sea urchins are round and spiny, ranging in diameter from . Sea urchins move slowly, crawling with tube feet, and also propel themselves with their spines. Although algae are the primary diet, sea urchins also eat slow-moving ( sessile) animals. Predators that eat sea urchins include a wide variety of fish, starfish, crabs, marine mammals. Sea urchins are also used as food especially in Japan. Adult sea urchins have fivefold symmetry, but their pluteus larvae feature bilateral (mirror) symmetry, indicating that the sea urchin belongs to the Bilateria group of animal phyla, which also comprises the chordates and the arthropods, the annelids and the molluscs, and are found in every ocean and in every climate, from the tropics to the po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halophila Baillonis
''Halophila baillonis'' is a species of aquatic plant in the family Hydrocharitaceae. It is referred to by the common name clover grass. It is native to Brazil, Cayman Islands, Colombia, Costa Rica, Jamaica, Leeward Islands, Netherlands Antilles, Panama, Puerto Rico, Trinidad and Tobago, and Venezuela. It is listed on the IUCN Red List as " vulnerable" due to its naturally rare occurrence and fragmented populations. Description This seagrass has fragile rhizomes with a single stem and a single root at each node. The shoots are erect and up to long, each with two obovate, keeled, scales in the central portion and a pseudo-whirl of four leaves at the tip. The leaf-blades are oblong to lanceolate, long by wide, with pronounced midribs and fine marginal serrations. There may be as many as 2,500 shoots per square metre. Distribution and habitat Clover grass is native to the Caribbean area. It is known from several sites in the Greater Antilles, Colombia, Venezuela and Bel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halophila Engelmannii
''Halophila engelmannii'' is a species of seagrass in the Hydrocharitaceae family. It is referred to by the common names star grass and Engelmann's seagrass and grows underwater on shallow sandy or muddy sea floors. It is native to the Bahamas, the Cayman Islands, Costa Rica, Cuba, the Gulf Coast of the United States, the Gulf Coast of Mexico, Puerto Rico, and Trinidad and Tobago. Description Halophila is the only genus of seagrass lacking basal sheaths on the leaf stems. Like other seagrasses, ''Halophila engelmannii'' has rhizomes that run along near the surface of sand or mud, with roots at the nodes to anchor them in place. Each leaf stem grows from a node and has a pair of scales halfway up and another pair at the base of the leaf blades. There are 4 to 8 blades on each stem, each of which is up to long and wide. Each blade is oval, has 6 to 8 veins and a finely serrated margin. Distribution ''Halophila engelmannii'' is found on the coasts of Florida, Texas, the Baham ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halophila Johnsonii
''Halophila johnsonii'', or Johnson's seagrass, is a small, asexual seagrass in the family Hydrocharitaceae (the "tape-grasses"). It occurs only on the southeastern coast of Florida, and was the first marine plant listed on the United States endangered species list, where it is listed as a threatened species. Female flowers have been observed, but even with decade long observational studies, neither male flowers nor seed have ever been observed.National Marine Fisheries Service. 2002. ''Recovery plan for Johnson's Seagrass (''Halophila johnsonii'')''. Prepared by the Johnson's Seagrass Recovery Team for the National Marine Fisheries Service, Silver Spring, Marylan/ref> It may have the most limited distribution of all seagrasses. It occurs only in lagoons along roughly 200 km of the Florida coastline between Sebastian Inlet and the northern part of Biscayne Bay, where it grows in small patches of a few centimeters to a few meters in diameter at depths ranging from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian River Lagoon
The Indian River Lagoon is a grouping of three lagoons: the Mosquito Lagoon, the Banana River, and the Indian River, on the Atlantic Coast of Florida; one of the most biodiverse estuaries in the Northern Hemisphere and is home to more than 4,300 species of plants and animals. The Lagoon contains five state parks, four federal wildlife refuges and a national seashore. The Lagoon varies in width from and averages in depth. History During glacial periods, the ocean receded. The area that is now the lagoon was grassland, from the beach. When the glaciers melted, the sea rose. The lagoon remained as captured water. The indigenous people who lived along the lagoon thrived on its fish and shellfish. This was determined by analyzing the middens they left behind, piled with refuse from clams, oysters, and mussels. The Indian River Lagoon was originally known on early Spanish maps as the ''Rio de Ais,'' after the Ais Indian tribe, who lived along the east coast of Florida. An exped ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euryhaline
Euryhaline organisms are able to adapt to a wide range of salinities. An example of a euryhaline fish is the molly (''Poecilia sphenops'') which can live in fresh water, brackish water, or salt water. The green crab ('' Carcinus maenas'') is an example of a euryhaline invertebrate that can live in salt and brackish water. Euryhaline organisms are commonly found in habitats such as estuaries and tide pools where the salinity changes regularly. However, some organisms are euryhaline because their life cycle involves migration between freshwater and marine environments, as is the case with salmon and eels. The opposite of euryhaline organisms are stenohaline ones, which can only survive within a narrow range of salinities. Most freshwater organisms are stenohaline, and will die in seawater, and similarly most marine organisms are stenohaline, and cannot live in fresh water. Osmoregulation Osmoregulation is the active process by which an organism maintains its level of water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seagrass
Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the order Alismatales (in the clade of monocotyledons). Seagrasses evolved from terrestrial plants which recolonised the ocean 70 to 100 million years ago. The name ''seagrass'' stems from the many species with long and narrow leaves, which grow by rhizome extension and often spread across large "meadows" resembling grassland; many species superficially resemble terrestrial grasses of the family Poaceae. Like all autotrophic plants, seagrasses photosynthesize, in the submerged photic zone, and most occur in shallow and sheltered coastal waters anchored in sand or mud bottoms. Most species undergo submarine pollination and complete their life cycle underwater. While it was previously believed this pollination was carried out without pollina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
