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Velella
''Velella'' is a monospecific genus of hydrozoa in the Porpitidae family. Its only known species is ''Velella velella'', a cosmopolitan free-floating hydrozoan that lives on the surface of the open ocean. It is commonly known by the names sea raft, by-the-wind sailor, purple sail, little sail, or simply ''Velella''. This small cnidarian is part of a specialised ocean surface community that includes the better-known cnidarian siphonophore, the Portuguese man o' war. Specialized predatory gastropod molluscs prey on these cnidarians. Such predators include nudibranchs (sea slugs) in the genus ''Glaucus''Gosliner, T.M. (1987). ''Nudibranchs of Southern Africa'' page 127, and purple snails in the genus ''Janthina''.Branch, G.M., Branch, M.L, Griffiths, C.L. and Beckley, L.E. (2010). ''Two Oceans: a guide to the marine life of southern Africa.'' Cape Town:Struik Nature. page 188. . Each apparent individual is a hydroid colony, and most are less than about 7 cm long. They are us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Velella In California April 2020
''Velella'' is a monospecific genus of hydrozoa in the Porpitidae family. Its only known species is ''Velella velella'', a Cosmopolitan distribution, cosmopolitan free-floating Hydrozoa, hydrozoan that lives on the surface of the open ocean. It is commonly known by the names sea raft, by-the-wind sailor, purple sail, little sail, or simply ''Velella''. This small cnidarian is part of a specialised ocean surface community that includes the better-known cnidarian siphonophore, the Portuguese man o' war. Specialized predatory gastropod molluscs prey on these cnidarians. Such predators include nudibranchs (sea slugs) in the genus Glaucus (gastropod), ''Glaucus''Gosliner, T.M. (1987). ''Nudibranchs of Southern Africa'' page 127, and purple snails in the genus ''Janthina''.Branch, G.M., Branch, M.L, Griffiths, C.L. and Beckley, L.E. (2010). ''Two Oceans: a guide to the marine life of southern Africa.'' Cape Town:Struik Nature. page 188. . Each apparent individual is a hydroid colony, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porpitidae
The chondrophores or porpitids are a small group of hydrozoans in the family Porpitidae. Though it derives from an outdated name for this lineage (see below), some still find the term "chondrophore" useful as a synonym to "porpitid" in discussions of the two genera contained therein. They all live at the surface of the open ocean, and are colonies of carnivorous, free-floating hydroids whose role in the plankton community is similar to that of pelagic jellyfish. The chondrophores look like a single organism but are actually colonial animals, made up of orderly cooperatives of polyps living under specialized sail-structures. The most familiar members of the family Porpitidae are the blue button ('' Porpita porpita'') and the by-the-wind sailor (''Velella velella''). Description The tiny individual animals are specialized to perform specific tasks; some form the central gas-filled disc (which is a golden brown colour and hardened by chitinous material) essential to keeping th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Locomotion
Animal locomotion, in ethology, is any of a variety of methods that animals use to move from one place to another. Some modes of locomotion are (initially) self-propelled, e.g., running, swimming, jumping, flying, hopping, soaring and gliding. There are also many animal species that depend on their environment for transportation, a type of mobility called passive locomotion, e.g., sailing (some jellyfish), kiting (spiders), rolling (some beetles and spiders) or riding other animals (phoresis). Animals move for a variety of reasons, such as to find food, a mate, a suitable microhabitat, or to escape predators. For many animals, the ability to move is essential for survival and, as a result, natural selection has shaped the locomotion methods and mechanisms used by moving organisms. For example, migratory animals that travel vast distances (such as the Arctic tern) typically have a locomotion mechanism that costs very little energy per unit distance, whereas non-migratory ani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuston
Neuston, also known as pleuston, are organisms that live at the surface of the ocean or an estuary, or at the surface of a lake, river or pond. Neuston can live on top of the water surface or may be attached to the underside of the water surface. They may also exist in the surface microlayer that forms between the top side and the underside. Neuston have been defined as "organisms living at the air/water interface of freshwater, estuarine, and marine habitats or referring to the biota on or directly below the water’s surface layer." The word neuston comes from the Greek ''neustos'', meaning "swimming" + -on (as in plankton). This term first appears in the biological literature in 1917. The alternative term pleuston comes from the Greek ''plein'', meaning "to sail or float". The first known use of this word was in 1909, before the first known use of neuston. In the past various authors have attempted distinctions between neuston and pleuston, but these distinctions have not been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plankton
Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish and whales. Marine plankton include bacteria, archaea, algae, protozoa and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in the freshwaters of lakes and rivers. Plankton are usually thought of as inhabiting water, but there are also airborne versions, the aeroplankton, that live part of their lives drifting in the atmosphere. These include plant spores, pollen and wind-scattered seeds, as well as microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air by sea spray. Though many p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Janthina
''Janthina'' is a genus of small to medium-sized pelagic or planktonic sea snails, marine gastropod molluscs in the family Epitoniidae.Gofas, S. (2011). Janthina Röding, 1798. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=138092 on 2011-11-01 Distribution Species in this genus occur worldwide in tropical, subtropical and warm seas. Description These snails are pelagic and live at the surface of the ocean. Adult snails may not be capable of swimming, and die when they are detached from their rafts; ''Janthina janthina'' larvae, however, actively swim in the water column. The adult snails prey upon (and live near to) one of several species of pelagic animals loosely known as jellyfish. More specifically they eat the medusae of free-swimming Cnidaria, in particular the genus known as "by-the-wind sailors", ''Velella''. The snails are able to float securely because they create a raft of clear chitin around air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaucus (gastropod)
''Glaucus'' is a genus of small blue pelagic sea slugs. They are aeolid nudibranchs,Bouchet, P.; Gofas, S. (2013)''Glaucus'' Forster, 1777.Accessed through: World Register of Marine Species on 2013-07-17 ranging in size from . They feed on colonial cnidarians such as Portuguese man o' wars, blue buttons, and purple sails. They can produce painful and potentially dangerous stings when handled, as they store the venomous nematocysts of their prey. ''Glaucus'' is the only genus in the family Glaucidae. It includes five species. Taxonomic history The genus ''Glaucus'' was established by monotypy in 1777 by the British naturalist Johann Reinhold Forster. He described specimens of ''Glaucus atlanticus'' recovered during the second voyage of James Cook aboard . The genus is named after the Greek sea-god Glaucus. In 1848, the German naturalist Johannes Gistel provided the substitute name ''Dadone'' for ''Glaucus''. But it is unnecessary and is now regarded as invalid.Bouchet, P. (2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portuguese Man O' War
The Portuguese man o' war (''Physalia physalis''), also known as the man-of-war, is a marine hydrozoan found in the Atlantic Ocean and the Indian Ocean. It is considered to be the same species as the Pacific man o' war or blue bottle, which is found mainly in the Pacific Ocean. The Portuguese man o' war is the only species in the genus ''Physalia'', which in turn is the only genus in the family Physaliidae. The Portuguese man o' war is a conspicuous member of the neuston, the community of organisms that live at the ocean surface. It has numerous venomous microscopic nematocysts which deliver a painful sting powerful enough to kill fish, and has been known to occasionally kill humans. Although it superficially resembles a jellyfish, the Portuguese man o' war is in fact a siphonophore. Like all siphonophores, it is a colonial organism, made up of many smaller units called zooids. All zooids in a colony are genetically identical, but fulfill specialized functions such as feedi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Irish Naturalist
''The Irish Naturalist'' was a scientific journal that was published in Dublin, Ireland, from April 1892 until December 1924. History The journal owed its establishment to the efforts of several leading Dublin naturalists, notably George H. Carpenter and R. M. Barrington. The first editors were Carpenter and Robert Lloyd Praeger, of the National Library of Ireland. The journal was supported by a number of societies, including the Royal Zoological Society of Ireland, the Dublin Microscopical Club, the Belfast Naturalists' Field Club, and the Dublin Naturalists' Field Club. ''The Irish Naturalist'' was published for 33 years and contained in total over 3000 pages. The journal ceased publication in December 1924. It had been having some financial problems, but the final blow came when Carpenter took up his appointment to the keepership of the Manchester Museum in 1923. The journal was succeeded in 1925 by the ''Irish Naturalists' Journal''. Contributors Among notable con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cnidocyst
A cnidocyte (also known as a cnidoblast or nematocyte) is an explosive cell containing one large secretory organelle called a cnidocyst (also known as a cnida () or nematocyst) that can deliver a sting to other organisms. The presence of this cell defines the phylum Cnidaria (corals, sea anemones, hydrae, jellyfish, etc.). Cnidae are used to capture prey and as a defense against predators. A cnidocyte fires a structure that contains a toxin within the cnidocyst; this is responsible for the stings delivered by a cnidarian. Structure and function Each cnidocyte contains an organelle called a cnida, cnidocyst, nematocyst, ptychocyst or spirocyst. This organelle consists of a bulb-shaped capsule containing a coiled hollow tubule structure attached to it. An immature cnidocyte is referred to as a cnidoblast or nematoblast. The externally oriented side of the cell has a hair-like trigger called a cnidocil, which is a mechano- and chemo-receptor. When the trigger is activated, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyp (zoology)
A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are roughly cylindrical in shape and elongated at the axis of the vase-shaped body. In solitary polyps, the aboral (opposite to oral) end is attached to the substrate by means of a disc-like holdfast called a pedal disc, while in colonies of polyps it is connected to other polyps, either directly or indirectly. The oral end contains the mouth, and is surrounded by a circlet of tentacles. Classes In the class Anthozoa, comprising the sea anemones and corals, the individual is always a polyp; in the class Hydrozoa, however, the individual may be either a polyp or a medusa, with most species undergoing a life cycle with both a polyp stage and a medusa stage. In class Scyphozoa, the medusa stage is dominant, and the polyp stage may or may not be present, depending on the family. In those scyphozoans that have the larval planula metamorphose into a polyp, the po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hayle
Hayle ( kw, Heyl, "estuary") is a port town and civil parish in west Cornwall, England. It is situated at the mouth of the Hayle River (which discharges into St Ives Bay) and is approximately seven miles (11 km) northeast of Penzance. Hayle parish was created in 1888 from part of the now defunct Phillack parish, with which it was later combined in 1935, and incorporated part of St Erth in 1937. The modern parish shares boundaries with St Ives to the west, St Erth to the south, Gwinear and Gwithian in the east, and is bounded to the north by the Celtic Sea. History Early history Although there is a long history of settlement in the Hayle Estuary area dating from the Bronze Age, the modern town of Hayle was built predominantly during the 18th century industrial revolution. Evidence of Iron Age settlement exists at the fort on the hill above Carnsew Pool where the Plantation now stands. It is thought that Hayle was an important centre for the neolithic tin industry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
