Rajiformes
Rajiformes is one of the four orders in the superorder Batoidea, flattened cartilaginous fishes related to sharks. Rajiforms are distinguished by the presence of greatly enlarged pectoral fins, which reach as far forward as the sides of the head, with a generally flattened body. The undulatory pectoral fin motion diagnostic to this taxon is known as rajiform locomotion. The eyes and spiracles are located on the upper surface of the head and the gill slits are on the underside of the body. Most species give birth to live young, although some lay eggs enclosed in a horny capsule ("mermaid's purse"). Characteristics Rajoids typically have a dorsoventrally flattened body. The snout is slender and pointed and the wide mouth, often covered with a fleshy nasal flap, is on the underside of the head. The eyes and well-developed spiracles are located on the top of the head. In most species, the spiracles are large and are the main means of drawing water in for respiration. There is no n ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Batoidea
Batoidea is a superorder of cartilaginous fishes, commonly known as rays. They and their close relatives, the sharks, comprise the subclass Elasmobranchii. Rays are the largest group of cartilaginous fishes, with well over 600 species in 26 families. Rays are distinguished by their flattened bodies, enlarged pectoral fins that are fused to the head, and gill slits that are placed on their ventral surfaces. Anatomy Batoids are flat-bodied, and, like sharks, are cartilaginous fish, meaning they have a boneless skeleton made of a tough, elastic cartilage. Most batoids have five ventral slot-like body openings called gill slits that lead from the gills, but the Hexatrygonidae have six. Batoid gill slits lie under the pectoral fins on the underside, whereas a shark's are on the sides of the head. Most batoids have a flat, disk-like body, with the exception of the guitarfishes and sawfishes, while most sharks have a spindle-shaped body. Many species of batoid have developed their pe ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Sclerorhynchiformes
Sclerorhynchoidei is an extinct suborder of rajiform rays that had long rostra with large denticles similar to sawfishes and sawsharks. This feature was convergently evolved and their closest living relatives are actually skates. While they are often called "sawfishes", sawskates is a more accurate common name for sclerorhynchoids. The suborder contains five named families: Ganopristidae, Ischyrhizidae, Onchopristidae, Ptychotrygonidae, and Schizorhizidae. Several genera (see below) are not currently placed in any of these families. Sclerorhynchoids first appeared in the Barremian and went extinct during the Cretaceous–Paleogene extinction event, with former Paleocene occurrences being misidentifications or reworked specimens. Phylogeny Below is a cladogram of Sclerorhynchoidei, with the topology based on Villalobos-Segura ''et al.'' (2021b) and the family taxonomy based on Greenfield (2021). Other genera *†''Agaleorhynchus'' *†''Ankistrorhynchus'' *†''Arch ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Anacanthobatidae
The Anacanthobatidae, the smooth skates or leg skates, are a family of skates found at depths below in the Indian, Pacific and Atlantic Oceans. They lack the dorsal denticles (sharp, tooth-like scales) of other rays, hence their name, from Greek ''an-'' meaning "without", ''acantha'' meaning "thorn", and ''bathys'' meaning "deep". They are bottom-dwelling fishes found on the continental slopes of tropical and subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ... waters. References Anacanthobatidae {{Rajiformes-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Sclerorhynchoidei
Sclerorhynchoidei is an extinct suborder of rajiform rays that had long rostra with large denticles similar to sawfishes and sawsharks. This feature was convergently evolved and their closest living relatives are actually skates. While they are often called "sawfishes", sawskates is a more accurate common name for sclerorhynchoids. The suborder contains five named families: Ganopristidae, Ischyrhizidae, Onchopristidae, Ptychotrygonidae, and Schizorhizidae. Several genera (see below) are not currently placed in any of these families. Sclerorhynchoids first appeared in the Barremian and went extinct during the Cretaceous–Paleogene extinction event, with former Paleocene occurrences being misidentifications or reworked specimens. Phylogeny Below is a cladogram of Sclerorhynchoidei, with the topology based on Villalobos-Segura ''et al.'' (2021b) and the family taxonomy based on Greenfield (2021). Other genera *†''Agaleorhynchus'' *†''Ankistrorhynchus'' *†''Arc ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Arhynchobatidae
Arhynchobatidae is a family of skates and is commonly known as the softnose skates. It belongs to the order Rajiformes in the superorder Batoidea of rays. At least 104 species have been described, in 13 genera. Softnose skates have at times been placed in the same family as hardnose skates, but most recent authors recognize them as a distinct family. Members of the Arhynchobatidae can be distinguished from hardnose skates in having a soft and flexible snout, as well as a more or less reduced rostrum. Genera The 13 recognized genera of softnose skates are: * '' Arhynchobatis'' * '' Atlantoraja'' * ''Bathyraja'' * '' Brochiraja'' * '' Insentiraja'' * '' Irolita'' * '' Notoraja'' * ''Pavoraja'' * ''Psammobatis'' * ''Pseudoraja'' * '' Rhinoraja'' * ''Rioraja The Rio skate (''Rioraja agassizii'') is a shallow water skate native to the Atlantic coast of South America from Brazil to southern Argentina. It is the only member of the monotypic genus ''Rioraja''. Named in honor of zool ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Gurgesiellidae
Pygmy skates are cartilaginous fish belonging to the family Gurgesiellidae in the superorder Batoidea of rays Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science and mathematics * Ray (geometry), half of a line proceeding from an initial point * Ray (gra .... Nineteen species in three genera are known.Weigmann, S., Séret, B., Last, P.R. & McEachran, J.D. 2016. Pygmy Skates, Family Gurgesiellidae. Pp. 473–493 in Last, P.R., White, W.T., Carvalho, M.R., Séret, B., Stehmann, M. & Naylor, G.J.P. (eds.). Rays of the World. CSIRO Publishing: Melbourne. . Genera * '' Cruriraja'' * '' Fenestraja'' * '' Gurgesiella'' References Ray families Rajiformes {{Rajiformes-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Anacanthobatis
''Anacanthobatis'' is a genus of smooth skate The Anacanthobatidae, the smooth skates or leg skates, are a family of skates found at depths below in the Indian, Pacific and Atlantic Oceans. They lack the dorsal denticles (sharp, tooth-like scales) of other rays, hence their name, from G ...s native to the western Indian Ocean, where found deeper than . Species Several species have been assigned to this genus, but most are now placed in '' Sinobatis'', '' Springeria'', and '' Schroederobatis'', leaving only ''A. marmoratus'' in ''Anacanthobatis''.Last, P.R., Weigmann, S. & Yang, L. (2016): Changes to the nomenclature of the skates (Chondrichthyes: Rajiformes). Seite 11 bis 34 in Last, P.R. & Yearsley, G.K. (Hrsg.) (2016): Rays of the World: Supplementary information. CSIRO Australian National Fish Collection. * '' Anacanthobatis marmoratus'' ( von Bonde & Swart, 1923) (spotted legskate) References Anacanthobatidae Ray genera {{Rajiformes-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Sclerorhynchidae
Ganopristidae is an extinct family of cartilaginous fish from the Cretaceous belonging to the suborder Sclerorhynchoidei. While the name Sclerorhynchidae is often used for this family, it is a junior synonym of Ganopristidae. This family contains the genera '' Libanopristis'', ''Micropristis'', and ''Sclerorhynchus ''Sclerorhynchus'' (from el, σκληρός , 'hard' and el, ῥύγχος 'snout') is an extinct genus of ganopristid sclerorhynchoid that lived during the Late Cretaceous. The genus ''Ganopristis'' is considered a junior synonym of ''Scler ...''. The type genus ''Ganopristis'' is considered to be a junior synonym of ''Sclerorhynchus''. References {{Taxonbar, from=Q108908110 Prehistoric cartilaginous fish families Rajiformes ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Sawfishes
Sawfish, also known as carpenter sharks, are a family of rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the largest fish with some species reaching lengths of about . They are found worldwide in tropical and subtropical regions in coastal marine and brackish estuarine waters, as well as freshwater rivers and lakes. They are endangered. They should not be confused with sawsharks (order Pristiophoriformes) or the extinct sclerorhynchoids (order Rajiformes) which have a similar appearance, or swordfish (family Xiphiidae) which have a similar name but a very different appearance. Sawfishes are relatively slow breeders and the females give birth to live young. They feed on fish and invertebrates that are detected and captured with the use of their saw. They are generally harmless to humans, but can inflict serious injuries with the saw when captured and defending ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Mermaid's Purse
An egg case or egg capsule, often colloquially called a mermaid's purse, is the casing that surrounds the eggs of oviparous sharks, skates and chimaeras. Egg cases typically contain one embryo, except for big skate and mottled skate egg cases, which contain up to 7 embryos. Oviparity is completely absent in the superorder Squalomorphii. Description Egg cases are made of collagen protein strands, and are often described as feeling rough and leathery. Some egg cases have a fibrous material covering the outside of the egg case, thought to aid in attachment to substrate. Egg cases without a fibrous outer layer can be striated, bumpy, or smooth and glossy. With the exception of bullhead shark eggs, egg cases are typically rectangular in shape with projections, called horns, at each corner. Depending on the species, egg cases may have one or more tendrils. Development Shortly after internal fertilization, the fertilized ovum enters the partially formed egg case located in the ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Pectoral Fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |