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Platyrhinoidis
The thornback guitarfish (''Platyrhinoidis triseriata'') is a species of ray in the family Platyrhinidae, and the only member of its genus. Despite its name and appearance, it is more closely related to electric rays than to true guitarfishes of the family Rhinobatidae. This species ranges from Tomales Bay to the Gulf of California, generally in inshore waters no deeper than . It can be found on or buried in sand or mud, or in and near kelp beds. Reaching in length, the thornback guitarfish has a heart-shaped pectoral fin disc and a long, robust tail bearing two posteriorly positioned dorsal fins and a well-developed caudal fin. The most distinctive traits of this plain-colored ray are the three parallel rows of large, hooked thorns that start from the middle of the back and run onto the tail. Encountered singly or in groups, the thornback guitarfish feeds on small, benthic invertebrates and bony fishes. It is aplacental viviparous, with the developing young drawing sustenance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platyrhinidae
The Platyrhinidae are a family (biology), family of Batoidea, rays, commonly known as thornbacks due to their dorsal rows of large thorns. They resemble guitarfishes in shape. Though traditionally classified with stingrays, molecular evidence suggests they are more closely related to electric rays in the order Torpediniformes. Genera and species * Genus ''Platyrhina'' Johannes Peter Müller, J. P. Müller & Friedrich Gustav Jakob Henle, Henle, 1838 ** ''Platyrhina hyugaensis'' Yukio Iwatsuki, Iwatsuki, Kei Miyamoto, Miyamoto & Kazuhiro Nakaya, Nakaya, 2011 (Hyuga fanray) ** ''Platyrhina sinensis'' Marcus Elieser Bloch, Bloch & Johann Gottlob Schneider, J. G. Schneider, 1801 (fanray) ** ''Platyrhina tangi'' Yukio Iwatsuki, Iwatsuki, Zhang Jie (ichthyologist), J. Zhang & Kazuhiro Nakaya, Nakaya, 2011 (yellow-spotted fanray) * Genus ''Platyrhinoidis'' Samuel Garman, Garman 1881 ** ''Platyrhinoidis triseriata'' David Starr Jordan, D. S. Jordan & Charles Henry Gilbert, Gilbert, 1880 (t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guitarfish
The guitarfish, also referred to as shovelnose rays, are a family, Rhinobatidae, of rays. The guitarfish are known for an elongated body with a flattened head and trunk and small, ray-like wings. The combined range of the various species is tropical, subtropical, and warm temperate waters worldwide. Names In Australia and New Zealand, guitarfish are commonly referred to as shovelnose rays or shovelnose sharks. Description Guitarfish have a body from intermediate between those of sharks and rays. The tail has a typical shark-like form, but in many species, the head has a triangular, or guitar-like shape, rather than the disc-shape formed by fusion with the pectoral fins found in other rays. Reproduction Guitarfish are ovoviviparous; the embryo matures inside an egg within the mother until it is ready to hatch. This is typical of rays. Habitat Guitarfish are bottom feeders that bury themselves in mud or sand and eat worms, crabs, and clams. Some can tolerate salt, fresh, and bra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Samuel Garman
Samuel Walton Garman (June 5, 1843 – September 30, 1927), or "Garmann" as he sometimes styled himself, was a naturalist/zoologist from Pennsylvania. He became noted as an ichthyologist and herpetologist. Biography Garman was born in Indiana County, Pennsylvania, on 5 June 1843. In 1868 he joined an expedition to the American West with John Wesley Powell. He graduated from the Illinois State Normal University in 1870, and for the following year was principal of the Mississippi State Normal School. In 1871, he became professor of natural sciences in Ferry Hall Seminary, Lake Forest, Illinois, and a year later became a special pupil of Louis Agassiz. He was a friend and regular correspondent of the naturalist Edward Drinker Cope, and in 1872 accompanied him on a fossil hunting trip to Wyoming. In 1870 he became assistant director of herpetology and ichthyology at Harvard's Museum of Comparative Zoology. His work was mostly in the classification of fish, especially sharks, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal 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 to lu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Mexico covers ,Mexico ''''. . making it the world's 13th-largest country by are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recreational Fishing
Recreational fishing, also called sport fishing or game fishing, is fishing for leisure, exercise or competition. It can be contrasted with commercial fishing, which is professional fishing for profit; or subsistence fishing, which is fishing for survival and livelihood. The most common form of recreational fishing is angling, which is done with a rig of rod, reel, line, hooks and any one of a wide range of baits, as well as other complementary devices such as weights, floats, swivels and method feeders, collectively referred to as '' terminal tackles''. Lures are frequently used in place of fresh bait when fishing for predatory fishes. Some hobbyists hand-make custom tackles themselves, including plastic lures and artificial flies. Other forms of recreational fishing include spearfishing, which is done with a speargun or harpoon usually while diving; and bowfishing, with is done from above the water with archery equipments such as a compound bow or crossbow. Noodl ... [...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] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Least Concern
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] |
International Union For Conservation Of Nature
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] |
Gestation Period
In mammals, pregnancy is the period of reproduction during which a female carries one or more live offspring from implantation in the uterus through gestation. It begins when a fertilized zygote implants in the female's uterus, and ends once it leaves the uterus. Fertilization and implantation During copulation, the male inseminates the female. The spermatozoon fertilizes an ovum or various ova in the uterus or fallopian tubes, and this results in one or multiple zygotes. Sometimes, a zygote can be created by humans outside of the animal's body in the artificial process of in-vitro fertilization. After fertilization, the newly formed zygote then begins to divide through mitosis, forming an embryo, which implants in the female's endometrium. At this time, the embryo usually consists of 50 cells. Development After implantation A blastocele is a small cavity on the center of the embryo, and the developing embryonary cells will grow around it. Then, a flat layer cell forms on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yolk Sac
The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though ''yolk sac'' is far more widely used. In humans, the yolk sac is important in early embryonic blood supply, and much of it is incorporated into the primordial gut during the fourth week of embryonic development. In humans The yolk sac is the first element seen within the gestational sac during pregnancy, usually at 3 days gestation. The yolk sac is situated on the front (ventral) part of the embryo; it is lined by extra-embryonic endoderm, outside of which is a layer of extra-embryonic mesenchyme, derived from the epiblast. Blood is conveyed to the wall of the yolk sac by the primitive aorta and after circulating through a wide-meshed capillary plexus, is returned by the vitelline veins to the tubular heart of the embryo. This constitutes the vitell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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