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Pelvic Fin
Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hindlimbs of tetrapods, which evolved from lobe-finned fish during the Middle Devonian. Structure and function Structure In actinopterygians, the pelvic fin consists of two endochondrally-derived bony girdles attached to bony radials. Dermal fin rays ( lepidotrichia) are positioned distally from the radials. There are three pairs of muscles each on the dorsal and ventral side of the pelvic fin girdle that abduct and adduct the fin from the body. Pelvic fin structures can be extremely specialized in actinopterygians. Gobiids and lumpsuckers modify their pelvic fins into a sucker disk that allow them to adhere to the substrate or climb structures, such as waterfalls. In priapiumfish, males have modified their pelvic structures into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Barb or the BARBs or ''variation'' may refer to: People * Barb (name), a list of people and fictional characters with the given name or surname * Barb, a term used by fans of Nicki Minaj to refer to themselves * The Barbs, a band Places * Barb, Ontario, Canada * DeKalb, Illinois, USA; nicknamed ''Barb City'' Animals * Barb (feather), the branches issuing from the rachis of feathers * Barb (fish), common name for a range of freshwater fish * Barb horse, a breed from North Africa * Barb (pigeon), a breed of domestic pigeon * Australian Kelpie or barb, a breed of dog * The Barb (1863–1888), Australian Thoroughbred racehorse Implements * Barding or barb, a type of armor for horses * A backward-facing point on a fish hook or similar implement, rendering extraction from the victim's flesh more difficult * A type of pipe fitting called barb, used to connect hosing (the ridges face backward, making insertion easy and removal difficult) * Barb, a shortened version of barbitura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepidotrichia
In a zoological context, spines are hard, needle-like anatomical structures found in both vertebrate and invertebrate species. The spines of most spiny mammals are modified hairs, with a spongy center covered in a thick, hard layer of keratin and a sharp, sometimes barbed tip. Occurrence Mammals Spines in mammals include the prickles of hedgehogs, and among rodents, the quills of porcupines (of both the New World and the Old), as well as the prickly fur of spiny mice, spiny pocket mice, and of species of spiny rat. They are also found on afrotherian tenrecs of the family Tenrecinae (hedgehog and streaked tenrecs), marsupial spiny bandicoots, and on echidnas (a monotreme). An ancient synapsid, ''Dimetrodon'', had extremely long spines on its backbone that were joined together with a web of skin that formed a sail-like structure. Many mammalian species, like cats and fossas, also have penile spines. The Mesozoic eutriconodont mammal '' Spinolestes'' already displayed sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelvic Fin Bud
The pelvis (: pelves or pelvises) is the lower part of an anatomical trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis or pelvic skeleton). The pelvic region of the trunk includes the bony pelvis, the pelvic cavity (the space enclosed by the bony pelvis), the pelvic floor, below the pelvic cavity, and the perineum, below the pelvic floor. The pelvic skeleton is formed in the area of the back, by the sacrum and the coccyx and anteriorly and to the left and right sides, by a pair of hip bones. The two hip bones connect the spine with the lower limbs. They are attached to the sacrum posteriorly, connected to each other anteriorly, and joined with the two femurs at the hip joints. The gap enclosed by the bony pelvis, called the pelvic cavity, is the section of the body underneath the abdomen and mainly consists of the reproductive organs and the rectum, while the pelvic floor at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zebrafish
The zebrafish (''Danio rerio'') is a species of freshwater ray-finned fish belonging to the family Danionidae of the order Cypriniformes. Native to South Asia, it is a popular aquarium fish, frequently sold under the trade name zebra danio (and thus often called a " tropical fish" although it is both tropical and subtropical). The zebrafish is an important and widely used vertebrate model organism in scientific research, particularly developmental biology, but also gene function, oncology, teratology, and drug development, in particular pre-clinical development. It is also notable for its regenerative abilities, and has been modified by researchers to produce many transgenic strains. Taxonomy The zebrafish is a derived member of the genus '' Brachydanio'', of the family Cyprinidae. It has a sister-group relationship with '' Danio aesculapii''. Zebrafish are also closely related to the genus '' Devario'', as demonstrated by a phylogenetic tree of close species. Distri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limb Development
Limb development in vertebrates is an area of active research in both developmental and evolutionary biology, with much of the latter work focused on the transition from fin to limb. Limb formation begins in the morphogenetic limb field, as mesenchymal cells from the lateral plate mesoderm proliferate to the point that they cause the ectoderm above to bulge out, forming a limb bud. Fibroblast growth factor (FGF) induces the formation of an organizer at the end of the limb bud, called the apical ectodermal ridge (AER), which guides further development and controls cell death. Programmed cell death is necessary to eliminate webbing between digits. The limb field is a region specified by expression of certain Hox genes, a subset of homeotic genes, and T-box transcription factors – Tbx5 for forelimb or wing development, and Tbx4 for leg or hindlimb development. Establishment of the forelimb field (but not hindlimb field) requires retinoic acid signaling in the developing trun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromyography
Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by skeletal muscles. EMG is performed using an instrument called an electromyograph to produce a record called an electromyogram. An electromyograph detects the electric potential generated by muscle cells when these cells are electrically or neurologically activated. The signals can be analyzed to detect abnormalities, activation level, or recruitment order, or to analyze the biomechanics of human or animal movement. Needle EMG is an electrodiagnostic medicine technique commonly used by neurologists. Surface EMG is a non-medical procedure used to assess muscle activation by several professionals, including physiotherapists, kinesiologists and biomedical engineers. In computer science, EMG is also used as middleware in gesture recognition towards allowing the input of physical action to a computer as a form of human-computer interaction. Clinical uses EMG testing has a varie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Priapiumfish
Phallostethidae, also known as priapium fish, is a family of Atheriniformes, atheriniform fish native to freshwater and brackish habitats in southeast Asia. They are small, no more than in length, with partially translucent bodies. They are found in fresh and brackish water from Thailand to the Philippines and Sulawesi. They are named for a muscular organ found under the chin of males. This organ, which may possess small testicles, is used together with the pelvic fins to grasp the female during mating. Unlike most other fish, priapium fishes exhibit internal fertilisation, although they are Oviparity, oviparous. Subdivision The family Phallostethidae is divided into two Subfamily, subfamilies and four genera: * Subfamily Phallostethinae Regan, 1916 ** Genus ''Neostethus'' Regan, 1916 ** Genus ''Phallostethus'' Regan, 1916 ** Genus ''Phenacostethus'' George S. Myers, Myers, 1928 * Subfamily Gulaphallinae Horst Joachim Aurich, Aurich, 1937 ** Genus ''Gulaphallus'' Albert William ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lumpsucker
The Cyclopteridae are a family of marine fishes, commonly known as lumpsuckers or lumpfish, in the order Scorpaeniformes. They are found in the cold waters of the Arctic Ocean, Arctic, Atlantic Ocean, North Atlantic, and Pacific Ocean, North Pacific oceans. The greatest number of species are found in the North Pacific. The family name ''Cyclopteridae'' derives from the Greek language, Greek words ''κύκλος'' (kyklos), meaning "circle", and ''πτέρυξ'' (pteryx), meaning "wing" or "fin", in reference to the circle-shaped pectoral fins of most of the fish in this family. Genera Cyclopteridae includes the following valid genera: Description Lumpsuckers are named appropriately enough; their portly bodies are nearly spherical with generally drab coloration and lithic patterns. The "sucker" part refers to the fish's modified pelvic fins, which have evolved into adhesive discs (located ventrally, behind the pectoral fins); the fish use these discs to adhere to the substrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gobiid
Gobiidae or gobies is a family of bony fish in the order Gobiiformes, one of the largest fish families comprising over 2,000 species in more than 200 genera. Most of gobiid fish are relatively small, typically less than in length, and the family includes some of the smallest vertebrates in the world, such as '' Trimmatom nanus'' and '' Pandaka pygmaea''. ''Trimmatom nanus'' are under long when fully grown, while the ''Pandaka pygmaea'' standard length is , with a maximum known standard length of . Some large gobies can reach over in length, but that is exceptional. Generally, they are benthic or bottom-dwellers. Although few are important as food fish for humans, they are of great significance as prey species for other commercially important fish such as cod, haddock, sea bass and flatfish. Several gobiids are also of interest as aquarium fish, such as the dartfish of the genus ''Ptereleotris''. Phylogenetic relationships of gobiids have been studied using molecular data. De ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endochondral Ossification
Endochondral ossification is one of the two essential pathways by which bone tissue is produced during fetal development and bone healing, bone repair of the mammalian skeleton, skeletal system, the other pathway being intramembranous ossification. Both endochondral and intramembranous processes initiate from a precursor mesenchymal cells, mesenchymal tissue, but their transformations into bone are different. In intramembranous ossification, mesenchymal tissue is directly converted into bone. On the other hand, endochondral ossification starts with mesenchymal tissue turning into an intermediate hyaline cartilage, cartilage stage, which is eventually substituted by bone. Endochondral ossification is responsible for development of most bones including long bone, long and short bone, short bones, the bones of the axial skeleton, axial (ribs and vertebrae) and the appendicular skeleton, appendicular skeleton (e.g. upper limb, upper and lower limb, lower limbs), the bones of the Base ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Fin
Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only by muscles. Fish fins are distinctive anatomical features with varying structures among different clades: in ray-finned fish (Actinopterygii), fins are mainly composed of bony spines or rays covered by a thin stretch of scaleless skin; in lobe-finned fish ( Sarcopterygii) such as coelacanths and lungfish, fins are short rays based around a muscular central bud supported by jointed bones; in cartilaginous fish ( Chondrichthyes) and jawless fish ( Agnatha), fins are fleshy " flippers" supported by a cartilaginous skeleton. Fins at different locations of the fish body serve different purposes, and are divided into two groups: the midsagittal ''unpaired fins'' and the more laterally located ''paired fins''. Unpaired fins are p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinopterygians
Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of skin supported by radially extended thin bony spines called ''lepidotrichia'', as opposed to the bulkier, fleshy lobed fins of the sister clade Sarcopterygii (lobe-finned fish). Resembling folding fans, the actinopterygian fins can easily change shape and wetted area, providing superior thrust-to-weight ratios per movement compared to sarcopterygian and chondrichthyian fins. The fin rays attach directly to the proximal or basal skeletal elements, the radials, which represent the articulation between these fins and the internal skeleton (e.g., pelvic and pectoral girdles). The vast majority of actinopterygians are teleosts. By species count, they dominate the subphylum Vertebrata, and constitute nearly 99% of the over 30,000 extant species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
