|
Quagga Catshark
The quagga catshark (''Halaelurus quagga'') is a species of catshark, belonging to the family Scyliorhinidae. A small, slim-bodied shark reaching in length, it has a distinctive color pattern of narrow, dark brown vertical bars, which resemble those of the quagga. Its head is short and flattened, with a pointed snout tip that is not upturned. Little is known of the quagga catshark's natural history, as it is known only from nine specimens caught off southwestern India and eastern Somalia. Inhabiting the offshore waters of continental shelf at depths of or more, it is a bottom-dwelling predator of shrimps. It exhibits an oviparous mode of reproduction, with a record of a female containing eight eggs that were enclosed in brown capsules bearing long tendrils at the corners. The International Union for Conservation of Nature (IUCN) presently lacks sufficient data to assess the conservation status of this species. It is not economically valued but is taken as bycatch. Taxonomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred William Alcock
Alfred William Alcock (23 June 1859 in Bombay – 24 March 1933 in Belvedere, Kent) was a British physician, naturalist, and carcinologist. Early life and education Alcock was the son of a sea-captain, John Alcock in Bombay, India who retired to live in Blackheath. His mother was a daughter of Christopher Puddicombe, the only son of a Devon squire. Alcock studied at Mill Hill School, at Blackheath Proprietary School and at Westminster School. In 1876 his father faced financial losses and he was taken out of school and sent to India in the Wynaad district. Here he was taken care of by relatives engaged in coffee-planting. As a boy of 17 he spent time in the jungles of Malabar. Career Coffee-planting in Wynaad declined and Alcock obtained a post at a commission agent's office in Calcutta. This office closed soon, and he worked from 1878 to 1880 in Purulia as an agent recruiting unskilled labourers for the Assam tea gardens. While here an acquaintance, Duncan Cameron, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiracle (vertebrates)
Spiracles () are openings on the surface of some animals, which usually lead to respiratory systems. The spiracle is a small hole behind each eye that opens to the mouth in some fish. In the jawless fish, the first gill opening immediately behind the mouth is essentially similar to the other gill opening. With the evolution of the jaw in the early jawed vertebrates, this gill slit was caught between the forward gill-rod (now functioning as the jaw) and the next rod, the hyomandibular bone, supporting the jaw hinge and anchoring the jaw to the skull proper. The gill opening was closed off from below, the remaining opening was small and hole-like, and is termed a spiracle. In many species of sharks and all rays the spiracle is responsible for the intake of water into the buccal space before being expelled from the gills. The spiracle is often located towards the top of the animal allowing breathing even while the animal is mostly buried under sediments. As sharks adapted a fast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nictitating Membrane
The nictitating membrane (from Latin '' nictare'', to blink) is a transparent or translucent third eyelid present in some animals that can be drawn across the eye from the medial canthus to protect and moisten it while maintaining vision. All Anura(tailless amphibians), and some reptiles, birds, and sharks have full nictitating membranes; in many mammals, a small, vestigial portion of the nictitating membrane remains in the corner of the eye. Some mammals, such as cats, camels, polar bears, seals and aardvarks, have full nictitating membranes. Often called a third eyelid or haw, it may be referred to in scientific terminology as the ''plica semilunaris'', ''membrana nictitans'', or ''palpebra tertia''. Description The nictitating membrane is a transparent or translucent third eyelid present in some animals that can be drawn across the eye for protection and to moisten it while maintaining vision. The term comes from the Latin word '' nictare'', meaning "to blink". It is o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halaelurus Quagga Fb2
''Halaelurus'' is a genus of catsharks in the family Scyliorhinidae. Species * '' Halaelurus boesemani'' S. Springer & D'Aubrey, 1972 (speckled catshark) * '' Halaelurus buergeri'' ( J. P. Müller & Henle, 1838) (blackspotted catshark) * '' Halaelurus lineatus'' Bass, D'Aubrey & Kistnasamy, 1975 (lined catshark) * ''Halaelurus maculosus'' W. T. White, Last & Stevens, 2007 (Indonesian speckled catshark) * ''Halaelurus natalensis'' (Regan, 1904) (tiger catshark) * '' Halaelurus quagga'' ( Alcock, 1899) (quagga catshark) * ''Halaelurus sellus'' W. T. White, Last A last is a mechanical form shaped like a human foot. It is used by shoemakers and cordwainers in the manufacture and repair of shoes. Lasts typically come in pairs and have been made from various materials, including hardwoods, cast iron, and ... & Stevens, 2007 (rusty catshark) References * Shark genera Taxa named by Theodore Gill {{Shark-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speckled Catshark
The speckled catshark (''Halaelurus boesemani'') is a catshark of the family Scyliorhinidae. It is found in the Gulf of Aden and off the coast of Somalia. It occurs at depths of between . Its length is up to 48 cm. Taxonomy In the past, this species was thought to occur both in the western Indian Ocean and in the waters around Vietnam, the Philippines, Indonesia, and Western Australia, between latitudes 21° N and 26° S. However, two new species of ''Halaelurus'' have been described from these latter areas, and the speckled catshark is now thought to be restricted to the western Indian Ocean. Description The speckled catshark grows to a maximum length of about . It has a pointed snout, small mouth and raised gill slits. The front of the first dorsal fin is situated above the hind third of the pelvic fin, while the front of the second dorsal fin, which is about the same size as the first, is situated above the hind third of the anal fin. The back and the base of the tail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gulf Of Aden
The Gulf of Aden ( ar, خليج عدن, so, Gacanka Cadmeed 𐒅𐒖𐒐𐒕𐒌 𐒋𐒖𐒆𐒗𐒒) is a deepwater gulf of the Indian Ocean between Yemen to the north, the Arabian Sea to the east, Djibouti to the west, and the Guardafui Channel, Socotra and Somalia to the south. In the northwest, it connects with the Red Sea through the Bab-el-Mandeb strait, and it connects with the Arabian Sea to the east. To the west, it narrows into the Gulf of Tadjoura in Djibouti. The ancient Greeks regarded the gulf as one of the most important parts of the Erythraean Sea. It later came to be dominated by Muslims, as the area around the gulf converted to Islam. From the late 1960s onwards, there started to be an increased Soviet naval presence in the Gulf. The importance of the Gulf of Aden declined when the Suez Canal was closed, but it was revitalized when the canal was reopened in 1975, after being deepened and widened by the Egyptian government. The waterway is part of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quilon
Kollam (), also known by its former name Quilon , is an ancient seaport and city on the Malabar Coast of India bordering the Laccadive Sea, which is a part of the Arabian Sea. It is north of the state capital Thiruvananthapuram. The city is on the banks of Ashtamudi Lake and the Kallada river. It is the headquarters of the Kollam district. Kollam is the fourth largest city in Kerala and is known for cashew processing and coir manufacturing. It is the southern gateway to the Backwaters of Kerala and is a prominent tourist destination. Kollam has a strong commercial reputation since ancient times. The Arabs, Phoenicians, Chinese, Ethiopians, Syrians, Jews, Chaldeans and Romans have all engaged in trade at the port of Kollam for millennia. As a result of Chinese trade, Kollam was mentioned by Ibn Battuta in the 14th century as one of the five Indian ports he had seen during the course of his twenty-four-year travels. [...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 wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USS Williamsburg (AGC-369)
USS ''Williamsburg'' was a US Navy gunboat. A former private yacht, it also served as a presidential yacht from 1945 to 1953. Private yacht The steel-hulled, diesel-powered yacht ''Aras'' was laid down on 19 March 1930 by the Bath Iron Works; launched on 8 December 1930, and delivered to wood-pulp magnate Hugh J. Chisholm, Jr., on 15 January 1931, who named it for his wife, the former Sara Hardenbergh. ''Aras'' displaced fully loaded; with a length of ; a beam of ; and a draft of . Her two Winton diesel engines generated , with a speed of . The US Navy acquired ''Aras'' on 24 April 1941 and renamed her ''Williamsburg''. The former pleasure craft entered the Brewer Drydock and Repair Co., of Brooklyn, New York, on 23 June, for conversion into a gunboat. US Naval service ''Williamsburg'' (PG-56) was commissioned at the New York Navy Yard, on 7 October 1941. ''Williamsburg'' was ordered to the Norfolk Navy Yard to complete fitting-out, arriving on 5 November. As a gunboat, '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trawl
Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different species of fishes or sometimes targeted species. Trawls are often called towed gear or dragged gear. The boats that are used for trawling are called trawlers or draggers. Trawlers vary in size from small open boats with as little as 30 hp (22 kW) engines to large factory trawlers with over 10,000 hp (7.5 MW). Trawling can be carried out by one trawler or by two trawlers fishing cooperatively ( pair trawling). Trawling can be contrasted with trolling. While trawling involves a net and is typically done for commercial usage, trolling instead involves a reed, rod and a bait or a lure and is typically done for recreational purposes. Trawling is also commonly used as a scientific sampling, or survey, method. Bottom vs. midwater tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Specimen
In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen. A taxon is a scientifically named grouping of organisms with other like organisms, a set that includes some organisms and excludes others, based on a detailed published description (for example a species description) and on the provision of type material, which is usually available to scientists for examination in a major museum research collection, or similar institution. Type specimen According to a precise set of rules laid down in the International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICN), the scientific name of every taxon is almost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Type Specimen")