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Roughskin Spurdog
The roughskin spurdog (''Cirrhigaleus asper'') is a dogfish of the family Squalidae, found circumglobally between latitudes 35°N and 35°S, at depths of between and . It reaches a length of . The roughskin spurdog is ovoviviparous with 21 to 22 young in a litter. Taxonomy The roughskin spurdog was first described in 1973 as ''Squalas Asper'' by British ichthyologist Nigel Merrett Nigel Robert Merrett (born 1940) is a British zoologist and ichthyologist and former director of the fish section of the British Natural History Museum A natural history museum or museum of natural history is a scientific institution with na .... It was later quickly changed to ''Cirrhigaleus asper.'' The roughskin spurdog is also known as the roughskin dogfish and roughskin dogshark in English. References * * Compagno, Dando, & Fowler, ''Sharks of the World'', Princeton University Press, New Jersey 2005 {{Taxonbar, from=Q377622 Cirrhigaleus Fish described in 1973 Taxa named b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nigel Merrett
Nigel Robert Merrett (born 1940) is a British zoologist and ichthyologist and former director of the fish section of the British Natural History Museum A natural history museum or museum of natural history is a scientific institution with natural history collections that include current and historical records of animals, plants, fungi, ecosystems, geology, paleontology, climatology, and more. .... In 1998, Merrett participated in an expedition headed by Nikolas Vasilyevich Parin to collect deepwater specimens. Book In 1997, Merrett, along with R.L. Haedrich, wrote the book ''Deep-Sea Demersal Fish and Fisheries''. In the book, they warn against fishing in deep water. References External linksSelect publications by Nigel R. Merrett British ichthyologists Living people 1940 births {{UK-zoologist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squaliformes
The Squaliformes are an order (biology), order of sharks that includes about 126 species in seven families. Members of the order have two dorsal fins, which usually possess spines, they usually have a sharp head, no anal fin or nictitating membrane, and five to seven gill slits. In most other respects, however, they are quite variable in form and size. Most species of the squaliform order live in saltwater or brackish water. They are found worldwide, from northern to tropical waters, and from shallow coastal seas to the open ocean. All members of the family Eptomeridae and Dalatiidae and ''Zameus squamulosus'' possess photophores, luminous organs, and exhibit intrinsic bioluminescence. Bioluminescence evolved once in Squaliformes, approximately 111–153 million years ago, and helped the Squaliformes radiate and adapt to the deep sea. The common ancestor of Dalatiidae, Etmopteridae, Somniosidae, and Oxynotidae possessed a luminous organ and used bioluminescence for camouf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squalidae
Squalidae, more commonly known as dogfish, dog sharks, or spiny dogfish, are one of several families of sharks categorized under Squaliformes, making it the second largest order of sharks, numbering 119 species across 7 families. Having earned their name after a group of fishermen reportedly observed the species chasing down smaller fish in dog-like packs, dogfish have slender, streamlined bodies, usually more compact in comparison to other species, and a pointed snout. Dogfish likewise have two dorsal fins, each with smooth spines, but no anal fin, and their skin is generally rough to the touch. As the species reaches adulthood, males usually measure a maximum of 39 inches (990 mm), while females typically measure 49 inches (1,200 mm) long. The species therefore exhibits female-dominant sexual dimorphism. Dogfish sharks have slate-gray or gray-brown skin with white dots that becomes paler (almost white) around the belly region. These sharks are characterized by teeth i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
35th Parallel North
The 35th parallel north is a circle of latitude that is 35 degrees north of the Earth's equatorial plane. It crosses Africa, the Mediterranean Sea, Asia, the Pacific Ocean, North America and the Atlantic Ocean. In the United States, the parallel defines the southern border of Tennessee, and the border between North Carolina and Georgia, as well as the tripoint of Arizona–California–Nevada. At this northern latitude, the Sun is visible for 14 hours, 31 minutes on its summer solstice (in June) and for 9 hours, 48 minutes on its winter solstice (in December). This parallel is sometimes used to define the northern boundary of the subtropics. Around the world Starting at the Prime Meridian and heading eastwards, the parallel 35° north passes through: : See also * 34th parallel north The 34th parallel north is a circle of latitude that is 34 degrees north of the Earth's equatorial plane. It crosses Africa, the Mediterranean Sea, Asia, the Pacific Ocean, North America and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
35th Parallel South
The 35th parallel south is a circle of latitude that is 35 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, the Indian Ocean, Australasia, the Pacific Ocean and South America. At this latitude the sun is visible for 14 hours, 31 minutes during the December solstice and 9 hours, 48 minutes during the June solstice. This parallel is sometimes used to define the southern boundary of the subtropics. Around the world Starting at the Prime Meridian and heading eastwards, the parallel 35° south passes through: : See also *34th parallel south *36th parallel south The 36th parallel south is a circle of latitude that is 36 degrees south of the Earth's equatorial plane. It crosses the Atlantic Ocean, the Indian Ocean, Australasia, the Pacific Ocean and South America. Around the world Starting at the Prim ... {{geographical coordinates, state=collapsed s35 Borders of Argentina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ovoviviparous
Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop inside eggs that remain in the mother's body until they are ready to hatch. The young of some ovoviviparous amphibians, such as ''Limnonectes larvaepartus'', are born as larvae, and undergo further metamorphosis outside the body of the mother. Members of genera ''Nectophrynoides'' and ''Eleutherodactylus'' bear froglets, not only the hatching, but all the most conspicuous metamorphosis, being completed inside the body of the mother before birth. Among insects that depend on opportunistic exploitation of transient food sources, such as many Sarcophagidae and other carrion flies, and species such as many Calliphoridae, that rely on fresh dung, and parasitoids such as tachinid flies that depend on entering the host as soon as possible, the emb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyologist
Ichthyology is the branch of zoology devoted to the study of fish, including bony fish ( Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 33,400 species of fish had been described as of October 2016, with approximately 250 new species described each year. Etymology The word is derived from the Greek words ἰχθύς, ''ikhthus'', meaning "fish"; and λογία, ''logia'', meaning "to study". History The study of fish dates from the Upper Paleolithic Revolution (with the advent of "high culture"). The science of ichthyology was developed in several interconnecting epochs, each with various significant advancements. The study of fish receives its origins from humans' desire to feed, clothe, and equip themselves with useful implements. According to Michael Barton, a prominent ichthyologist and professor at Centre College, "the earliest ichthyologists were ''hunters and gatherers'' who had learned how to obtain the most usef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leonard Compagno
Leonard Joseph Victor Compagno is an international authority on shark taxonomy and the author of many scientific papers and books on the subject, best known of which is his 1984 catalogue of shark species produced for the Food and Agriculture Organization (FAO) of the United Nations. Compagno was mentioned in the credits of the 1975 film ''Jaws'' along with the National Geographic Society. Career *Ph.D, Stanford University, 1979 *Adjunct professor, San Francisco State University, 1979 to 1985 *Curator of Fishes in the Division of Life Sciences and Head of the Shark Research Centre (SRC), Iziko Museums, Cape Town *Director, Shark Research Institute(SRI) Selected bibliography *Compagno, L.J.V., 1979. ''Carcharhinoid sharks: morphology, systematics and phylogeny''. Unpublished Ph. D. Thesis, Stanford University, 932 p. Available from University Microfilms International, Ann Arbor, Michigan. *Leonard Compagno, 1984a. FAO The Food and Agriculture Organization of the United Nati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirrhigaleus
''Cirrhigaleus'' is a genus of sharks in the Squalidae (dogfish) family, which is part of the Squaliformes order. Species * ''Cirrhigaleus asper'' Merrett, 1973 (roughskin spurdog) * ''Cirrhigaleus australis'' W. T. White, Last & Stevens, 2007 (southern mandarin dogfish) http://www.mapress.com/zootaxa/2007f/z01560p030f.pdf * ''Cirrhigaleus barbifer The mandarin dogfish (''Cirrhigaleus barbifer'') is a dogfish, a member of the family Squalidae in the order Squaliformes. It is found at depths of off southern Japan, Taiwan, and Indonesia ( Bali and Lombok). Populations off Australia and ...'' S. Tanaka (I), 1912 (mandarin dogfish) References * {{Taxonbar, from=Q139320 Shark genera Taxa named by Shigeho Tanaka ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Described In 1973
Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a vertebrate, true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed placodermi, external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
