Perciformes, also called the Percomorpha or Acanthopteri, is an order or superorder of ray-finned fish. If considered a single order, they are the most numerous order of vertebrates, containing about 41% of all bony fish. Perciformes means "perch-like". This group comprises over 10,000 species found in almost all aquatic ecosystems.
In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration. Scales are quite common and have evolved multiple times through convergent evolution, with varying structure and function.
Clupeidae is a family of ray-finned fishes, comprising, for instance, the herrings, shads, sardines, hilsa, and menhadens. The clupeoids include many of the most important food fishes in the world, and are also commonly caught for production of fish oil and fish meal. Many members of the family have a body protected with shiny cycloid scales, a single dorsal fin, with a fusiform body for quick, evasive swimming and pursuit of prey composed of small planktonic animals. Due to their small size, and position in the lower trophic level of many marine food webs, the levels of methylmercury they bioaccumulate are very low, reducing the risk of mercury poisoning when consumed.
A tautochrone or isochrone curve is the curve for which the time taken by an object sliding without friction in uniform gravity to its lowest point is independent of its starting point. The curve is a cycloid, and the time is equal to π times the square root of the radius over the acceleration of gravity. The tautochrone curve is the same as the brachistochrone curve for any given starting point.
In mathematics and physics, a brachistochrone curve, or curve of fastest descent, is the one lying on plane between a point A and a lower point B, where B is not directly below A, on which a bead slides frictionlessly under the influence of a uniform gravitational field to a given end point in the shortest time. The problem was posed by Johann Bernoulli in 1696.
Labrisomids are small blennioids (blennies), perciform marine fish belonging to the family Labrisomidae. Found mostly in the tropical Atlantic and Pacific Ocean, the family contains about 110 species in 15 genera.
Clinidae is a family of blennioids; perciform marine fish. Temperate blennies, the family ranges from the Atlantic, Pacific and Indian Oceans, in both the Southern and Northern Hemispheres. The family contains about 86 species in 20 genera, the 60-cm-long giant kelpfish being the largest; most are far smaller.
Sweepers are small, tropical marine perciform fish of the family Pempheridae. Found in the western Atlantic Ocean and Indo-Pacific region, the family contains about 26 species in two genera. One species is the target of subsistence fisheries in Japan, where the fish is much enjoyed for its taste. Sweepers are occasionally kept in marine aquaria.
A cycloidal drive or cycloidal speed reducer is a mechanism for reducing the speed of an input shaft by a certain ratio. Cycloidal speed reducers are capable of relatively high ratios in compact sizes.
Exocoetus is a genus of flying fishes.
1. It is a bony fish
2. The body is covered with cycloid scales
3. Mouth is wide, jaws bear teeth
4. It is marine fish
5. The tail has a hypobatic fins as the ventral lobe
Eucyclogobius newberryi, the Northern tidewater goby, is a species of goby native to lagoons of streams along the coast of California, United States..
Visual calculus, invented by Mamikon Mnatsakanian, is an approach to solving a variety of integral calculus problems. Many problems that would otherwise seem quite difficult yield to the method with hardly a line of calculation, often reminiscent of what Martin Gardner calls "aha! solutions" or Roger Nelsen a proof without words.
In geometry, Cavalieri's principle, a modern implementation of the method of indivisibles, named after Bonaventura Cavalieri, is as follows:
Chioninia is a genus of skinks, lizards in the subfamily Lygosominae. For long, this genus was included in the "wastebin taxon" Mabuya. The genus Chioninia contains the Cape Verde mabuyas.
The skin of most fishes is covered with scales, which, in many cases, are animal reflectors or produce animal coloration. Scales vary enormously in size, shape, structure, and extent, ranging from strong and rigid armour plates in fishes such as shrimpfishes and boxfishes, to microscopic or absent in fishes such as eels and anglerfishes. The morphology of a scale can be used to identify the species of fish it came from.
Cyrtodactylus triedrus, also known as the spotted bent-toed gecko, Sri Lanka gecko, spotted bow-fingered gecko, or spotted ground gecko, is a species of gecko endemic to island of Sri Lanka.
The Pseudaminae is a subfamily of ray-finned fishes, one of two subfamilies of the family Apogonidae, the cardinalfishes. They are characterised by having large caniform teeth which are placed on the on dentary and premaxillae, by having the lateral line absent or incomplete, by having no scales or if scales are present they are cycloid. One species, Gymnapogon urospilotus, is notable for its larvae being rather large and fast-swimming.
