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Clupeidae - Alosa Elongata
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 (very smooth and uniform) scales, a single dorsal fin, and 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. Description and biology Clupeids are mostly marine forage fish, although a few species are found in fresh water. No species has scales on the head, and some are entirely scaleless. The lateral line is short or absent, and the teeth are unusually small where they are present at all. Clupe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlantic Herring
Atlantic herring (''Clupea harengus'') is a herring in the family (biology), family Clupeidae. It is one of the most abundant fish species in the world. Atlantic herrings can be found on both sides of the Atlantic Ocean, congregating in large Shoaling and schooling, schools. They can grow up to in length and weigh up to . They feed on copepods, krill and small fish, while their natural predators are pinniped, seals, whales, cod and other larger fish. The Atlantic herring fishery has long been an important part of the economy of New England and the Canada, Canadian Atlantic provinces. This is because the fish congregate relatively near to the coast in massive schools, notably in the cold waters of the semi-enclosed Gulf of Maine and Gulf of Saint Lawrence, Gulf of St. Lawrence. North Atlantic herring schools have been measured up to in size, containing an estimated 4 billion fish. Description Atlantic herring have a wikt:fusiform, fusiform body. Gill rakers in their mouths fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury Poisoning
Mercury poisoning is a type of metal poisoning due to exposure to mercury. Symptoms depend upon the type, dose, method, and duration of exposure. They may include muscle weakness, poor coordination, numbness in the hands and feet, skin rashes, anxiety, memory problems, trouble speaking, trouble hearing, or trouble seeing. High-level exposure to methylmercury is known as Minamata disease. Methylmercury exposure in children may result in acrodynia (pink disease) in which the skin becomes pink and peels. Long-term complications may include kidney problems and decreased intelligence. The effects of long-term low-dose exposure to methylmercury are unclear. Forms of mercury exposure include metal, vapor, salt, and organic compound. Most exposure is from eating fish, amalgam-based dental fillings, or exposure at a workplace. In fish, those higher up in the food chain generally have higher levels of mercury, a process known as biomagnification. Less commonly, poisoning may occur a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odontocete
The toothed whales (also called odontocetes, systematic name Odontoceti) are a parvorder of cetaceans that includes dolphins, porpoises, and all other whales possessing teeth, such as the beaked whales and sperm whales. Seventy-three species of toothed whales are described. They are one of two living groups of cetaceans, the other being the baleen whales (Mysticeti), which have baleen instead of teeth. The two groups are thought to have diverged around 34 million years ago (mya). Toothed whales range in size from the and vaquita to the and sperm whale. Several species of odontocetes exhibit sexual dimorphism, in that there are size or other morphological differences between females and males. They have streamlined bodies and two limbs that are modified into flippers. Some can travel at up to 20 knots. Odontocetes have conical teeth designed for catching fish or squid. They have well-developed hearing, that is well adapted for both air and water, so much so that some can surviv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sharks
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimorpha (or Selachii) and are the sister group to the rays. However, the term "shark" has also been used to refer to all extinct members of Chondrichthyes with a shark-like morphology, such as hybodonts and xenacanths. The oldest modern sharks are known from the Early Jurassic. They range in size from the small dwarf lanternshark (''Etmopterus perryi''), a deep sea species that is only in length, to the whale shark (''Rhincodon typus''), the largest fish in the world, which reaches approximately in length. Sharks are found in all seas and are common to depths up to . They generally do not live in freshwater, although there are a few known exceptions, such as the bull shark and the river shark, which can be found in both seawater and freshwat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birds
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piscivorous
A piscivore () is a carnivorous animal that eats primarily fish. The name ''piscivore'' is derived . Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted reptiles and synapsids evolved herbivory. Almost all predatory fishes (most sharks, tuna, billfishes, pikes etc.) are obligated piscivores. Some non-piscine aquatic animals, such as whales, sea lion and crocodilians, are not completely piscivorous, often also preying on invertebrates, marine mammals, waterbirds and even wading land animals in addition to fish; while others, such as the bulldog bat and gharial, are strictly dependent on fish for food. Some creatures, including cnidarians, octopuses, squid, spiders, cetaceans, grizzly bears, jaguars, wolves, snakes, turtles and sea gulls, may have fish as significa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shoaling And Schooling
In biology, any group of fish that stay together for social reasons are shoaling, and if the group is swimming in the same direction in a coordinated manner, they are schooling. In common usage, the terms are sometimes used rather loosely. About one quarter of fish species shoal all their lives, and about one half shoal for part of their lives. Fish derive many benefits from shoaling behaviour including defence against predators (through better predator detection and by diluting the chance of individual capture), enhanced foraging success, and higher success in finding a mate. It is also likely that fish benefit from shoal membership through increased hydrodynamic efficiency. Fish use many traits to choose shoalmates. Generally they prefer larger shoals, shoalmates of their own species, shoalmates similar in size and appearance to themselves, healthy fish, and kin (when recognized). The oddity effect posits that any shoal member that stands out in appearance will be preferen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swim Bladder
The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled Organ (anatomy), organ that contributes to the ability of many bony fish (but not cartilaginous fish) to control their buoyancy, and thus to stay at their current water depth without having to expend energy in swimming. Also, the Dorsum (biology), dorsal position of the swim bladder means the center of mass is below the centroid, center of volume, allowing it to act as a stabilizing agent. Additionally, the swim bladder functions as a resonator, resonating chamber, to produce or receive sound. The swim bladder is evolutionarily Homology (biology), homologous to the lungs. Charles Darwin remarked upon this in ''On the Origin of Species''.Darwin, Charles (1859''Origin of Species''Page 190, reprinted 1872 by D. Appleton. Darwin reasoned that the lung in air-breathing vertebrates had derived from a more primitive swim bladder. In the embryonic stages, some species, such as Ophioblennius atlanticus, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleogene
The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago (annum, Mya) to the beginning of the Neogene Period Mya. It is the beginning of the Cenozoic Era of the present Phanerozoic Eon. The earlier term Tertiary Period was used to define the span of time now covered by the Paleogene Period and subsequent Neogene Period; despite no longer being recognised as a formal stratigraphy, stratigraphic term, 'Tertiary' is still widely found in earth science literature and remains in informal use. Paleogene is often abbreviated "Pg" (but the United States Geological Survey uses the abbreviation PE for the Paleogene on the Survey's geologic maps). During the Paleogene, evolution of mammals, mammals diversified from relatively small, simple forms into a large group of diverse animals in the wake of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmoniform
Salmonidae is a family (biology), family of ray-finned fish that constitutes the only currently extant family in the order (biology), order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), Salvelinus, chars, freshwater whitefishes, Thymallus, graylings, Hucho, taimens and lenoks, which are collectively known as the salmonids ("salmon-like fish"). The Atlantic salmon (''Salmo salar''), whose Latin name became that of its genus ''Salmo'', is also the source of the family and order names. Salmonids have a relatively primitive appearance among the teleost fish, with the pelvic fins being placed far back, and an adipose fin towards the rear of the back. They have slender bodies, with rounded fish scale, scales and forked tails, and their fish jaw, mouths contain a single row of sharp teeth. Although the smallest species is just long as an adult, most are much larger, with the largest reaching . All salmonids spawn in fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paedomorphic
Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny is found in modern humans compared to other primates. In progenesis or paedogenesis, sexual development is accelerated. Both neoteny and progenesis result in paedomorphism (as having the form typical of children) or paedomorphosis (changing towards forms typical of children), a type of heterochrony. It is the retention in adults of traits previously seen only in the young. Such retention is important in evolutionary biology, domestication and evolutionary developmental biology. Some authors define paedomorphism as the retention of larval traits, as seen in salamanders.Schell, S. C. ''Handbook of Trematodes of North America North of Mexico'', 1985, pg. 22 History and etymology The origins of the concept of neoteny have been traced to the Bible (as argued by Ashley Monta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sundasalangidae
''Sundasalanx'', the Sundaland noodlefishes, is the only genus in the family Sundasalangidae, which belongs to the same order as the herrings and their relatives. This family of extremely small fishes is restricted to freshwater environments of Southeast Asia with Indonesia being home to the majority of species. The seven currently recognized species in this genus are: * '' Sundasalanx malleti'' Siebert & Crimmen, 1997 * '' Sundasalanx megalops'' Siebert & Crimmen, 1997 * '' Sundasalanx mekongensis'' Britz & Kottelat, 1999 * '' Sundasalanx mesops'' Siebert & Crimmen, 1997 * '' Sundasalanx microps'' T. R. Roberts, 1981 * '' Sundasalanx platyrhynchus'' Siebert & Crimmen, 1997 * '' Sundasalanx praecox'' T. R. Roberts, 1981 (dwarf noodlefish) The FishBase classifies ''Sundasalanx'' as a pedomorphic genus within the family Clupeidae Clupeidae is a family of ray-finned fishes, comprising, for instance, the herrings, shads, sardines, hilsa, and menhadens. The clupeoids i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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