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New Zealand Eagle Ray
The New Zealand eagle ray or Australian eagle ray (''Myliobatis tenuicaudatus'') is an eagle ray of the family (biology), family Myliobatidae, found in bays, estuaries, and near rocky reefs around New Zealand and southern Australia on the inner continental shelf. It is a common species and the International Union for Conservation of Nature has assessed its conservation status as being of "least concern". Taxonomy ''Myliobatis tenuicaudatus'' was first described in 1877 by the Scottish naturalist James Hector who was director of the geological survey of New Zealand; the fish was thought to be Endemism, endemic to New Zealand. Subsequently, in 1881, the Australian zoologist William John Macleay described ''Myliobatis australis'' from the waters of Southern Australia as a new species. In a generic revision in 2014, W.T. White determined that the two are synonym (taxonomy), synonymous, and that ''M. australis'' is a junior synonym of ''M. tenuicaudatus''. Description The New Zeala ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Hector
Sir James Hector (16 March 1834 – 6 November 1907) was a Scottish-New Zealand geologist, naturalist, and surgeon who accompanied the Palliser Expedition as a surgeon and geologist. He went on to have a lengthy career as a government employed man of science in New Zealand, and during this period he dominated the Colony's scientific institutions in a way that no single man has since. Early life He was born at 11 Danube Street in Stockbridge, Edinburgh the son of Alexander Hector WS and his wife, Margaret Macrostie. He attended the Edinburgh Academy from 1844 to 1845. At 14, he began articles as an actuary at his father's office. He joined University of Edinburgh as a medical student and received his medical degree in 1856 at the age of 22. Palliser expedition Shortly after receiving his medical degree, upon the recommendation of Sir Roderick Murchison – director-general of the British Geological Survey – Hector was appointed geologist on the Palliser Expedition under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Victoria (Australia)
Victoria is a state in southeastern Australia. It is the second-smallest state with a land area of , the second most populated state (after New South Wales) with a population of over 6.5 million, and the most densely populated state in Australia (28 per km2). Victoria is bordered by New South Wales to the north and South Australia to the west, and is bounded by the Bass Strait to the south (with the exception of a small land border with Tasmania located along Boundary Islet), the Great Australian Bight portion of the Southern Ocean to the southwest, and the Tasman Sea (a marginal sea of the South Pacific Ocean) to the southeast. The state encompasses a range of climates and geographical features from its temperate coastal and central regions to the Victorian Alps in the northeast and the semi-arid north-west. The majority of the Victorian population is concentrated in the central-south area surrounding Port Phillip Bay, and in particular within the metropolit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Department Of Conservation (New Zealand)
The Department of Conservation (DOC; Māori: ''Te Papa Atawhai'') is the public service department of New Zealand charged with the conservation of New Zealand's natural and historical heritage. An advisory body, the New Zealand Conservation Authority (NZCA) is provided to advise DOC and its ministers. In addition there are 15 conservation boards for different areas around the country that provide for interaction between DOC and the public. Function Overview The department was formed on 1 April 1987, as one of several reforms of the public service, when the ''Conservation Act 1987'' was passed to integrate some functions of the Department of Lands and Survey, the Forest Service and the Wildlife Service. This act also set out the majority of the department's responsibilities and roles. As a consequence of Conservation Act all Crown land in New Zealand designated for conservation and protection became managed by the Department of Conservation. This is about 30% of New Z ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Least-concern Species
A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. They do not qualify as threatened, near threatened, or (before 2001) conservation dependent. Species cannot be assigned the "Least Concern" category unless they have had their population status evaluated. That is, adequate information is needed to make a direct, or indirect, assessment of its risk of extinction based on its distribution or population status. Evaluation Since 2001 the category has had the abbreviation "LC", following the IUCN 2001 Categories & Criteria (version 3.1). Before 2001 "least concern" was a subcategory of the "Lower Risk" category and assigned the code "LR/lc" or lc. Around 20% of least concern taxa (3261 of 15636) in the IUCN database still use the code "LR/lc", which indicates they have not been re-evaluate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juveniles of the target species. The term "bycatch" is also sometimes used for untargeted catch in other forms of animal harvesting or collecting. Non- marine species (freshwater fish not saltwater fish) that are caught (either intentionally or unintentionally) but regarded as generally "undesirable" are referred to as "rough fish" (mainly US) and " coarse fish" (mainly UK). In 1997, the Organisation for Economic Co-operation and Development (OECD) defined bycatch as "total fishing mortality, excluding that accounted directly by the retained catch of target species". Bycatch contributes to fishery decline and is a mechanism of overfishing for unintentional catch. The average annual bycatch rate of pinnipeds and cetaceans in the US from 199 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroreception
Electroreception and electrogenesis are the closely-related biological abilities to perceive electrical stimuli and to generate electric fields. Both are used to locate prey; stronger electric discharges are used in a few groups of fishes to stun prey. The capabilities are found almost exclusively in aquatic or amphibious animals, since water is a much better conductor of electricity than air. In passive electrolocation, objects such as prey are detected by sensing the electric fields they create. In active electrolocation, fish generate a weak electric field and sense the different distortions of that field created by objects that conduct or resist electricity. Active electrolocation is practised by two groups of weakly electric fish, the Gymnotiformes (knifefishes) and the Mormyridae (elephantfishes), and by ''Gymnarchus niloticus'', the African knifefish. An electric fish generates an electric field using an electric organ, modified from muscles in its tail. The field is ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polychaete
Polychaeta () is a paraphyletic class (biology), class of generally marine invertebrate, marine annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. More than 10,000 species are described in this class. Common representatives include the lugworm (''Arenicola marina'') and the Alitta virens, sandworm or Alitta succinea, clam worm ''Alitta''. Polychaetes as a class are robust and widespread, with species that live in the coldest ocean temperatures of the abyssal plain, to forms which tolerate the extremely high temperatures near hydrothermal vents. Polychaetes occur throughout the Earth's oceans at all depths, from forms that live as plankton near the surface, to a 2- to 3-cm specimen (still unclassified) observed by the robot ocean probe Nereus (underwater vehicle), ''Nereus'' at the bottom of the Challenger Deep, the deepes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crab
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the world's oceans, in freshwater, and on land, are generally covered with a thick exoskeleton, and have a single pair of pincers. They first appeared during the Jurassic Period. Description Crabs are generally covered with a thick exoskeleton, composed primarily of highly mineralized chitin, and armed with a pair of chelae (claws). Crabs vary in size from the pea crab, a few millimeters wide, to the Japanese spider crab, with a leg span up to . Several other groups of crustaceans with similar appearances – such as king crabs and porcelain crabs – are not true crabs, but have evolved features similar to true crabs through a process known as carcinisation. Environment Crabs are found in all of the world's oceans, as well as in fresh w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oyster
Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not all oysters are in the superfamily Ostreoidea. Some types of oysters are commonly consumed (cooked or raw), and in some locales are regarded as a delicacy. Some types of pearl oysters are harvested for the pearl produced within the mantle. Windowpane oysters are harvested for their translucent shells, which are used to make various kinds of decorative objects. Etymology The word ''oyster'' comes from Old French , and first appeared in English during the 14th century. The French derived from the Latin , the feminine form of , which is the latinisation of the Ancient Greek () 'oyster'. Compare () 'bone'. Types True oysters True oysters are members of the family Ostreidae. This family includes the edible oysters, which mainly belong t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clam
Clam is a common name for several kinds of bivalve molluscs. The word is often applied only to those that are edible and live as infauna, spending most of their lives halfway buried in the sand of the seafloor or riverbeds. Clams have two shells of equal size connected by two adductor muscles and have a powerful burrowing foot. They live in both freshwater and marine environments; in salt water they prefer to burrow down into the mud and the turbidity of the water required varies with species and location; the greatest diversity of these is in North America. Clams in the culinary sense do not live attached to a substrate (whereas oysters and mussels do) and do not live near the bottom (whereas scallops do). In culinary usage, clams are commonly eaten marine bivalves, as in clam digging and the resulting soup, clam chowder. Many edible clams such as palourde clams are ovoid or triangular; however, razor clams have an elongated parallel-sided shell, suggesting an old-fashioned ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthopelagic
The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of the larger profundal zone. Being just above the ocean floor, the demersal zone is variable in depth and can be part of the photic zone where light can penetrate, and photosynthetic organisms grow, or the aphotic zone, which begins between depths of roughly and extends to the ocean depths, where no light penetrates. Fish The distinction between demersal species of fish and pelagic species is not always clear cut. The Atlantic cod (''Gadus morhua'') is a typical demersal fish, but can also be found in the open water column, and the Atlantic herring (''Clupea harengus'') is predominantly a pelagic species but forms large aggregations near the seabed when it spawns on banks of gravel. Two types of fish inhabit the demersal zone: those ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seagrass Meadow
A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and long green, grass-like leaves. They produce seeds and pollen and have roots and rhizomes which anchor them in seafloor sand. Seagrasses form dense underwater meadows which are among the most productive ecosystems in the world. They provide habitats and food for a diversity of marine life comparable to that of coral reefs. This includes invertebrates like shrimp and crabs, cod and flatfish, marine mammals and birds. They provide refuges for endangered species such as seahorses, turtles, and dugongs. They function as nursery habitats for shrimps, scallops and many commercial fish species. Seagrass meadows provide coastal storm protection by the way their leaves absorb energy from waves as they hit the coast. They keep coastal waters healthy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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