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Yellowback Stingaree
The yellowback stingaree (''Urolophus sufflavus'') is a locally abundant but little-known species of stingray in the family Urolophidae. It is almost endemic to New South Wales, with a range from Green Cape northward, extending only barely into Queensland (Stradbroke Island). It inhabits soft-substrate habitats and has been reported from depths of 45–300 metres (150–980 ft), though it is most common on the outer continental shelf at depths of 100–160 metres (330–520 ft). This species attains a maximum length of 42 cm (17 in). It has a flattened pectoral fin disk about as wide as long, with rounded corners and straight anterior margins. There is a skirt-like nasal curtain in front of the mouth, without lateral lobes. The tail is short and stout, measuring 64-76% the length of the disk and bearing a serrated spine. The tail ends in a small caudal fin; there are no dorsal fins or lateral folds. The skin is devoid of dermal denticles. The colouration ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gilbert Percy Whitley
Gilbert Percy Whitley (9 June 1903 – 18 July 1975) was a British-born Australian ichthyologist and malacologist who was Curator of Fishes at the Australian Museum in Sydney for about 40 years. He was born at Swaythling, Southampton, England, and was educated at King Edward VI School, Southampton and the Royal Naval College, Osborne. Whitley migrated with his family to Sydney in 1921 and he joined the staff of the Australian Museum in 1922 while studying zoology at Sydney Technical College and the University of Sydney. In 1925 he was formally appointed Ichthyologist (later Curator of Fishes) at the Museum, a position he held until retirement in 1964. During his term of office he doubled the size of the ichthyological collection to 37,000 specimens through many collecting expeditions. Whitley was also a major force in the Royal Zoological Society of New South Wales, of which he was made a Fellow in 1934 and where he served as president during 1940–41, 1959–60 and 1973–74. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fecundity
Fecundity is defined in two ways; in human demography, it is the potential for reproduction of a recorded population as opposed to a sole organism, while in population biology, it is considered similar to fertility, the natural capability to produce offspring, measured by the number of gametes (eggs), seed set, or asexual propagules. Superfecundity refers to an organism's ability to store another organism's sperm (after copulation) and fertilize its own eggs from that store after a period of time, essentially making it appear as though fertilization occurred without sperm (i.e. parthenogenesis). Human demography Human demography considers only human fecundity, at its culturally differing rates, while population biology studies all organisms. The term ''fecundity'' in population biology is often used to describe the rate of offspring production after one time step (often annual). In this sense, fecundity may include both birth rates and survival of young to that time step. Whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urolophus
''Urolophus'' is a genus of round rays mostly native to the western Pacific Ocean and the Indian Ocean, though one species occurs in the Pacific waters of the Mexican coast. Müller and Henle erected ''Urolophus'' in an 1837 issue of ''Bericht Akademie der Wissenschaften zu Berlin''. The name is derived from the Greek ''oura'', meaning "tail", and ''lophos'', meaning "crest". In ''Urolophus'', the outer rims of the nostrils are not enlarged into lobes, but may form a small knob at the back. A fossil species, ''Urolophus crassicaudatus'', has been found in Monte Bolca, northern Italy, in deposits dating back to the late Ypresian stage of the Eocene epoch (49 Ma); however, Marramà ''et al.'' (2020) transferred this species to the genus '' Arechia''. Species There are currently 21 recognized species in this genus: * '' Urolophus aurantiacus'' J. P. Müller & Henle, 1841 (Sepia stingray) * †'' Urolophus bicuneatus'' Noetling, 1885 * '' Urolophus bucculentus'' W. J. Macleay, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Conservation Union
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partnerships. The organization is best known to the wider pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vulnerable Species
A vulnerable species is a species which has been Conservation status, categorized by the International Union for Conservation of Nature as being threatened species, threatened with extinction unless the circumstances that are threatened species, threatening its survival and reproduction improve. Vulnerability is mainly caused by habitat loss or destruction of the species' home. Vulnerable habitat or species are monitored and can become increasingly threatened. Some species listed as "vulnerable" may be common in captivity (animal), captivity, an example being the military macaw. There are currently 5196 animals and 6789 plants classified as Vulnerable, compared with 1998 levels of 2815 and 3222, respectively. Practices such as cryoconservation of animal genetic resources have been enforced in efforts to conserve vulnerable breeds of livestock specifically. Criteria The International Union for Conservation of Nature uses several criteria to enter species in this category. A tax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sydney
Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mountains to the west, Hawkesbury to the north, the Royal National Park to the south and Macarthur to the south-west. Sydney is made up of 658 suburbs, spread across 33 local government areas. Residents of the city are known as "Sydneysiders". The 2021 census recorded the population of Greater Sydney as 5,231,150, meaning the city is home to approximately 66% of the state's population. Estimated resident population, 30 June 2017. Nicknames of the city include the 'Emerald City' and the 'Harbour City'. Aboriginal Australians have inhabited the Greater Sydney region for at least 30,000 years, and Aboriginal engravings and cultural sites are common throughout Greater Sydney. The traditional custodians of the land on which modern Sydney stands are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gillnet
Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. The floats are sometimes called "corks" and the line with corks is generally referred to as a "cork line." The line along the bottom of the panels is generally weighted. Traditionally this line has been weighted with lead and may be referred to as "lead line." A gillnet is normally set in a straight line. Gillnets can be characterized by mesh size, as well as colour and type of filament from which they are made. Fish may be caught by gillnets in three ways: # Wedged – held by the mesh around the body. # Gilled – held by mesh slipping behind the opercula. # Tangled – held by teeth, spines, maxillaries, or other protrusions without the body penetrating the mesh. Most often fish are gilled. A fish swims into a net and passes only part way through the mesh. When it struggles to free ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otter Trawl
Bottom trawling is trawling (towing a trawl, which is a fishing net) along the seafloor. It is also referred to as "dragging". The scientific community divides bottom trawling into benthic trawling and demersal trawling. Benthic trawling is towing a net at the very bottom of the ocean and demersal trawling is towing a net just above the benthic zone. Bottom trawling can be contrasted with midwater trawling (also known as pelagic trawling), where a net is towed higher in the water column. Midwater trawling catches pelagic fish such as anchovies and mackerel, whereas bottom trawling targets both bottom-living fish (groundfish) and semi-pelagic species such as cod, squid, shrimp, and rockfish. Trawling is done by a trawler, which can be a small open boat with only or a large factory trawler with . Bottom trawling can be carried out by one trawler or by two trawlers fishing cooperatively (pair trawling). Global catch from bottom trawling has been estimated at over 30 million to ... [...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] |
Commercial Fishing
Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions. Large-scale commercial fishing is also known as industrial fishing. The major fishing industries are not only owned by major corporations but by small families as well. In order to adapt to declining fish populations and increased demand, many commercial fishing operations have reduced the sustainability of their harvest by fishing further down the food chain. This raises concern for fishery managers and researchers, who highlight how further they say that for those reasons, the sustainability of the marine ecosystems could be in danger of collapsing. Commercial fishermen harvest a wide variety of animals. However, a very small number of species support the majority of the world ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Sequence
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gene– ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome C
The cytochrome complex, or cyt ''c'', is a small hemeprotein found loosely associated with the inner membrane of the mitochondrion. It belongs to the cytochrome c family of proteins and plays a major role in cell apoptosis. Cytochrome c is highly water-soluble, unlike other cytochromes, and is an essential component of the respiratory electron transport chain, where it carries one electron. It is capable of undergoing oxidation and reduction as its iron atom converts between the ferrous and ferric forms, but does not bind oxygen. It transfers electrons between Complexes III (Coenzyme Q – Cyt c reductase) and IV (Cyt c oxidase). In humans, cytochrome c is encoded by the ''CYCS'' gene. Species distribution Cytochrome c is a highly conserved protein across the spectrum of eukaryotic species, found in plants, animals, fungi, and many unicellular organisms. This, along with its small size (molecular weight about 12,000 daltons), makes it useful in studies of cladistics. Cyt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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