The bigeye thresher (Alopias superciliosus) is a species of thresher shark, family Alopiidae, found in temperate and tropical oceans worldwide. Like the other thresher sharks, nearly half its total length consists of the elongated upper lobe of the tail fin. Its common name comes from its enormous eyes, which are placed in keyhole-shaped sockets that allow them to be rotated upward. This species can also be distinguished by a pair of deep grooves on the top of its head, from which its scientific name is derived.
The large eyes of the bigeye thresher are adapted for hunting in low light conditions. It is one of the few sharks that conduct a diel vertical migration, staying in deep water during the day and moving into surface waters at night to feed. To protect its sensitive brain and eyes from the temperature changes accompanying these movements, the bigeye thresher has a vascular exchange system called the rete mirabile around those organs. This species feeds mainly on fish and squid, which are stunned via whip-like strikes of the long tail. Bigeye threshers are ovoviviparous, usually bearing litters of two pups. The embryos are oophagous and feed on ova produced by the mother while inside the uterus. This shark is caught by commercial fisheries across its range; the meat is not highly regarded but the skin, fins, and liver oil are valued. It has been assessed as Vulnerable by the International Union for Conservation of Nature (IUCN). (Full article...)
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The Halloween darter (Percina crypta) is a small freshwater fish native to North America. It is found in Georgia and Alabama in the drainage basin of the Apalachicola River, specifically in the Flint River system and the Chattahoochee River system. It prefers shallow, fast-flowing areas with gravel bottoms in small and medium-sized rivers. It was first described in 2008, having not previously been distinguished from the Blackbanded darter (P. nigrofasciata), formerly thought to occur in the same watershed. Blackbanded darter has since been split again with Westfall's darter now recognised from the Apalachicola drainage. The species is somewhat variable, being generally blackish dorsally, with some individuals having indistinct saddle-like barring. Males have orange and dark lateral striping while females have dark stripes and a yellowish-green belly. At a maximum standard length of 101 mm (4 in), males are slightly larger than females, and both sexes develop distinctive orange barring on the edge of the first dorsal fin during the breeding season.
The Tasmanian numbfish (Narcine tasmaniensis) is a species of electric ray in the familyNarcinidae. Endemic to southeastern Australia, this common ray inhabits shallow continental shelf waters in the southern portion of its range and deeper continental slope waters in the northern portion of its range. It prefers sand and mud habitats. This species can be identified by its spade-shaped pectoral fin disc with concave anterior margins, long tail with well-developed skin folds along either side, and plain dark brown dorsal colouration. Its maximum known length is 47 cm (19 in).
The dark shyshark or pretty happy (Haploblepharus pictus) is a species of catshark, belonging to the familyScyliorhinidae, endemic to the temperate waters off southern Namibia and western South Africa. It is benthic in nature and inhabits shallow, inshore waters and favors rocky reefs and kelp forests. Growing to 60 cm (24 in) long, this small, stocky shark has a wide, flattened head with a rounded snout and a large flap of skin extending from before the nostrils to the mouth. Its dorsal coloration is extremely variable and may feature black-edged orange to blackish saddles and/or white spots on a light brown to nearly black background.
The marbled electric ray (Torpedo marmorata) is a species of electric ray in the familyTorpedinidae found in the coastal waters of the eastern Atlantic Ocean from the North Sea to South Africa. This benthic fish inhabits rocky reefs, seagrass beds, and sandy and muddy flats in shallow to moderately deep waters. It can survive in environments with very little dissolved oxygen, such as tidal pools. The marbled electric ray has a nearly circular pectoral fin disc and a muscular tail that bears two dorsal fins of nearly equal size and a large caudal fin. It can be identified by the long, finger-like projections on the rims of its spiracles, as well as by its dark brown mottled color pattern, though some individuals are plain-colored. Males and females typically reach 36–38 cm (14–15 in) and 55–61 cm (22–24 in) long respectively.
Nocturnal and solitary, the marbled electric ray can often be found lying the sea floor buried except for its eyes and spiracles. This slow-moving predator feeds almost exclusively on small bony fishes, which it ambushes from the bottom and subdues with strong electric bursts. It defends itself by turning towards the threat, swimming in a loop, or curling up with its underside facing outward, while emitting electric shocks to drive off the prospective predator. Its paired electric organs are capable of producing 70–80 volts of electricity. This species is aplacental viviparous, with the developing embryos sustained by yolk and histotroph ("uterine milk") produced by the mother. Mating takes place from November to January, and females bear litters of 3–32 pups every other year after a gestation period of 9–12 months. The newborn ray is immediately capable of using electricity to hunt. (Full article...)
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The Japanese sleeper ray (Narke japonica) is a species of electric ray in the familyNarkidae. It is common in the inshore and offshore waters of the northwestern Pacific Ocean from southern Japan to southern China. Growing up to 40 cm (16 in) long, the Japanese sleeper ray has a nearly circular pectoral fin disc colored reddish to chocolate brown above, sometimes with darker or lighter spots, and lighter brown below. The spiracles behind its small eyes have raised, smooth rims. Its short and muscular tail bears a single dorsal fin positioned aft of the rounded pelvic fins, and terminates in a large caudal fin.
The plain maskray (Neotrygon annotata) or brown stingray, is a species of stingray in the familyDasyatidae. It is found in shallow, soft-bottomed habitats off northern Australia. Reaching 24 cm (9.4 in) in width, this species has a diamond-shaped, grayish green pectoral fin disc. Its short, whip-like tail has alternating black and white bands with fin folds above and below. There are short rows of thorns on the back and the base of the tail, but otherwise the skin is smooth. While this species possesses the dark mask-like pattern across its eyes common to its genus, it is not ornately patterned like other maskrays.
Ambassis macleayi, commonly known as Macleay's glassfish, Macleay's glass perchlet, Macleay's perchlet, reticulated glassfish, reticulated perchlet, or network perchlet, is a species of freshwater fish in the family Ambassidae. It is native to northern Australia and the trans-Fly River region of New Guinea. It is a fish with a vertically flat, narrow body and a standard length generally between 35 and 45 mm (1.4 and 1.8 in), with large specimens reaching 77 mm (3.0 in) long. It generally eats water fleas and other small invertebrates. This fish is considered to be a least-concern species according to the International Union for Conservation of Nature (IUCN), although it could suffer from habitat degradation due to feral pigs and invasive water plants such as the water hyacinth. The fish is suitable for aquarium use in tanks containing other non-aggressive species. (Full article...)
Female yellow stingrays are larger than males. Females reach about a maximum length of about 26 inches whereas the male will reach a maximum legth of about 15 inches across. The yellow stingray has a round pectoral fin disc and a short tail with a well-developed caudal fin. It has a highly variable but distinctive dorsal color pattern consisting of either light-on-dark or dark-on-light reticulations forming spots and blotches, and can rapidly change the tonality of this coloration to improve its camouflage. (Full article...)
Named for its pale coloration, it is closely related to the relatively common shovelnose sturgeon (Scaphirhynchus platorynchus), but is much larger, averaging between 30 and 60 inches (76 and 152 cm) in length and 85 pounds (39 kg) in weight at maturity. This species takes 15 years to mature and spawns infrequently, but can live up to a century. A member of the sturgeon family, Acipenseridae, which originated during the Cretaceous period 70 million years ago, the pallid sturgeon has changed little since then. (Full article...)
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The smoothtooth blacktip shark (Carcharhinus leiodon) is a species of requiem shark in the family Carcharhinidae. It is known only from the type specimen caught from the Gulf of Aden, off eastern Yemen, and a handful of additional specimens caught from the Persian Gulf, off Kuwait. Reaching 1.3 m (4.3 ft) in length, this species has a stocky greenish-colored body, a short snout, and black-tipped fins. It can be distinguished from similar species by its teeth, which are narrow, erect, and smooth-edged.
Little is known of the smoothtooth blacktip shark's natural history; it likely inhabits shallow waters and feeds on small bony fishes. It is presumably viviparous like other members of its family. The International Union for Conservation of Nature last assessed this species as endangered. Although more specimens have since been discovered, the conservation status of this species remains precarious due to heavy fishing and habitat degradation within its range. (Full article...)
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The common thresher (Alopias vulpinus), also known as Atlantic thresher, is the largest species of thresher shark, family Alopiidae, reaching some 6 m (20 ft) in length. About half of its length consists of the elongated upper lobe of its caudal fin. With a streamlined body, short pointed snout, and modestly sized eyes, the common thresher resembles (and has often been confused with) the pelagic thresher (A. pelagicus). It can be distinguished from the latter species by the white of its belly extending in a band over the bases of its pectoral fins. The common thresher is distributed worldwide in tropical and temperate waters, though it prefers cooler temperatures. It can be found both close to shore and in the open ocean, from the surface to a depth of 550 m (1,800 ft). It is seasonally migratory and spends summers at lower latitudes.
The long tail of the common thresher, the source of many fanciful tales through history, is used in a whip-like fashion to deliver incapacitating blows to its prey. This species feeds mainly on small schoolingforage fishes such as herrings and anchovies. It is a fast, strong swimmer that has been known to leap clear of the water, and possesses physiological adaptations that allow it to maintain an internal body temperature warmer than that of the surrounding sea water. The common thresher has an aplacental viviparous mode of reproduction, with oophagousembryos that feed on undeveloped eggs ovulated by their mother. Females typically give birth to four pups at a time, following a gestation period of nine months. (Full article...)
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The Christmas darter (Etheostoma hopkinsi) is a species of ray-finned fish, a darter from the subfamilyEtheostomatinae, part of the familyPercidae which includes the perches, ruffes and pike-perches. It is found in the Savannah, Ogeechee and Altamaha catchment areas in South Carolina and Georgia. It is a small but colorful fish, typically less than 5 cm (2 in) in total length, with blackish, red and green streaks on its flanks. Green and red are associated with Christmas, hence the common nameChristmas darter. Like other darters, it lives on or close to the stream-bed, in riffles and vegetation-laden stretches of small rivers, creeks and spring-fed streams. It feeds on aquatic insects and probably breeds in the spring, but its biology and behavior are poorly known.
The Christmas darter is closely related to the Savannah darter and the Christmas Eve or Hannukah darter, the latter of which is sometimes considered a subspecies of the Christmas darter rather than a species in its own right. The Christmas darter may hybridize with other darter species, though hybridization is hampered by behavioral and biological barriers. The Christmas darter is a common species in suitable habitat and the International Union for Conservation of Nature (IUCN) has assessed it as being of least concern for conservation purposes. In South Carolina, it is considered a conservation priority species, as it may be threatened in future by impoundment of rivers, siltation and deforestation. (Full article...)
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The pigeye shark or Java shark (Carcharhinus amboinensis) is an uncommon species of requiem shark, in the family Carcharhinidae, found in the warm coastal waters of the eastern Atlantic and western Indo-Pacific. It prefers shallow, murky environments with soft bottoms, and tends to roam within a fairly localised area. With its bulky grey body, small eyes, and short, blunt snout, the pigeye shark looks almost identical to (and is often confused with) the better-known bull shark (C. leucas). The two species differ in vertebral count, the relative sizes of the dorsal fins, and other subtle traits. This shark typically reaches lengths of 1.9–2.5 m (6.2–8.2 ft).
The pigeye shark is an apex predator that mostly hunts low in the water column. It has a varied diet, consisting mainly of bony and cartilaginous fishes and also including crustaceans, molluscs, sea snakes, and cetaceans. This species gives birth to live young, with the developing embryos sustained to term via a placental connection to their mother. Litters of three to thirteen pups are born after a gestation period of nine or twelve months. Young sharks spend their first few years of life in sheltered inshore habitats such as bays, where their movements follow tidal and seasonal patterns. The pigeye shark's size and dentition make it potentially dangerous, though it has not been known to attack humans. The shark is infrequently caught in shark nets protecting beaches and by fisheries, which use it for meat and fins. The IUCN presently assesses this species as vulnerable. (Full article...)
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Roughtail stingray (Bathytoshia centroura) at McGrail Bank, Gulf of Mexico
The roughtail stingray (Bathytoshia centroura) is a species of stingray in the familyDasyatidae, with separate populations in coastal waters of the northwestern and southwestern Atlantic Ocean. This bottom-dwelling species typically inhabits sandy or muddy areas with patches of invertebrate cover, at a depth of 15–50 m (49–164 ft). It is seasonally migratory, overwintering in offshore waters and moving into coastal habitats for summer. The largest whip-tail stingray in the Atlantic, the roughtail stingray grows up to 2.6 m (8.5 ft) across and 360 kg (800 lb) in weight. It is plain in color, with an angular, diamond-shaped pectoral fin disc and a long, whip-like tail bearing a subtle fin fold underneath. The many thorns on its back and tail serve to distinguish it from other stingrays that share its range.
The great northern tilefish (Lopholatilus chamaeleonticeps) or golden tile, is the largest species in the family Malacanthidae (tilefishes). It grows to a length of between 38 and 44 inches (970 and 1,120 mm). The great northern tilefish is a slow-growing and long-lived species that has four stages of life. After hatching from eggs, the larvae are found in plankton. As they grow into juveniles, the individuals seek shelter until finding or making their own burrows. As adults, the tilefish continue to expand their burrows in the sediment throughout their lives. The diet of the larvae is unknown, but presumed to consist of zooplankton; juveniles and adults feed upon various benthicinvertebrates, crustaceans, and fish. After reaching sexual maturity between 5 and 7 years of age, females lay eggs throughout the mating season for the male to fertilize, with each female laying an average of 2.3 million eggs.
The great northern tilefish fishery has been regulated to prevent overfishing. Regulations include catch limits and gear restrictions to prevent damage to the species' habitat and population. The result of these regulations has been a rebounding of the population, which led to an increase in the 2012 catch limit in the southern part of the Atlantic seaboard. (Full article...)
... that the Tellico Dam project was controversial for its acquisition of farmland for real estate development, loss of Native American sites, and damaging an endangered fish habitat?
Image 4An annotated diagram of the basic external features of an abyssal grenadier and standard length measurements. (from Deep-sea fish)
Image 5Scale diagram of the layers of the pelagic zone (from Pelagic fish)
Image 6The stoplight loosejaw is also one of the few fishes that produce red bioluminescence. As most of their prey cannot perceive red light, this allows it to hunt with an essentially invisible beam of light. (from Deep-sea fish)
Image 7Red snapper, are generalized reef feeders with standard jaw and mouth structures that allow them to eat almost anything, though they prefer small fish and crustaceans. (from Coral reef fish)
Image 8Scale diagram of the layers of the pelagic zone (from Deep-sea fish)
Image 16The stargazer is an ambush predator which can deliver both venom and electric shocks. It has been called "the meanest thing in creation". (from Coastal fish)
Image 17The huge ocean sunfish, a true resident of the ocean epipelagic zone, sometimes drifts with the current, eating jellyfish. (from Pelagic fish)
Image 18Most of the rest of the mesopelagic fishes are ambush predators, such as this sabertooth fish. The sabertooth uses its telescopic, upward-pointing eyes to pick out prey silhouetted against the gloom above. Their recurved teeth prevent a captured fish from backing out. (from Pelagic fish)
Image 25Shortfin mako shark make long seasonal migrations. They appear to follow temperature gradients, and have been recorded travelling more than 4,500 km in one year. (from Pelagic fish)
Image 26Oceanic fish inhabit the oceanic zone, which is the deep open water which lies beyond the continental shelves. (from Pelagic fish)
Image 27World distribution of plankton (from Coastal fish)
Image 28Areas of upwelling in red (from Coastal fish)
Image 32Humans seldom encounter frilled sharks alive, so they pose little danger (though scientists have accidentally cut themselves examining their teeth). (from Deep-sea fish)
Image 33Lanternfish are partial residents of the ocean epipelagic zone During the day they hide in deep waters, but at night they migrate up to surface waters to feed. (from Pelagic fish)
Image 41The giant whale shark, another resident of the ocean epipelagic zone, filter feeds on plankton, and periodically dives deep into the mesopelagic zone. (from Pelagic fish)
Image 42Bigeye tuna cruise the epipelagic zone at night and the mesopelagic zone during the day (from Deep-sea fish)
Image 49Young, red flabby whalefish make nightly vertical migrations into the lower mesopelagic zone to feed on copepods. When males mature into adults, they develop a massive liver and then their jaws fuse shut. They no longer eat, but continue to metabolise the energy stored in their liver. (from Pelagic fish)
Image 50In the foreground is an orange-lined triggerfish displaying spines. Triggerfish have mouths that crush shells. Orange-lined triggerfish are particularly aggressive. The black and white fish are three-stripe damselfish and the unstriped fish are blue-green chromis damselfish. If the triggerfish attacks, the damselfish will hide in the nearby cauliflower coral. If the triggerfish wants to hide, it will squeeze into a coral crevice and lock itself in place with its spines. (from Coral reef fish)
Image 53Cod-like fishes, like this morid cod have a barbel (fleshy filament) on their lower jaw which they use to detect prey buried in the sand or mud. (from Coastal fish)
Image 54Surgeonfish are among the most common of coral reef herbivores, often feeding in shoals. This may be a mechanism for overwhelming the highly aggressive defence responses of small territorial damselfishes that vigorously guard small patches of algae on coral reefs. (from Coral reef fish)
Image 58The humpback anglerfish is a bathypelagic ambush predator, which attracts prey with a bioluminescent lure. It can ingest prey larger than itself, which it swallows with an inrush of water when it opens its mouth. (from Pelagic fish)
Image 67The stoplight loosejaw has a lower jaw one-quarter as long as its body. The jaw has no floor and is attached only by a hinge and a modified tongue bone. Large fang-like teeth in the front are followed by many small barbed teeth. (from Deep-sea fish)
Image 72Most mesopelagic fishes are small filter feeders that ascend at night to feed in the nutrient rich waters of the epipelagic zone. During the day, they return to the dark, cold, oxygen-deficient waters of the mesopelagic where they are relatively safe from predators. Lanternfish account for as much as 65% of all deep sea fish biomass and are largely responsible for the deep scattering layer of the world's oceans. (from Pelagic fish)
Image 74Coral reefs support flourishing ecosystems, paradoxically in clear, low nutrient waters, along tropical continental coasts and around volcanic islands. Coral reef fish are numerous and diverse. (from Coastal fish)
Image 75Many bristlemouth species, such as the "spark anglemouth" above, are also bathypelagic ambush predators that can swallow prey larger than themselves. They are among the most abundant of all vertebrate families. (from Pelagic fish)
Image 76The usually placid yellow tang can erect spines in its tail and slash at its opponent with rapid sideways movements (from Coral reef fish)
Image 77Some flatfish can camouflage themselves on the ocean floor (from Demersal fish)
Image 80Long-snouted lancetfish. Lancetfish are ambush predators which spend all their time in the mesopelagic zone. They are among the largest mesopelagic fishes (up to 2 m). (from Deep-sea fish)
A sketch of a longnose sawshark (Pristiophorus cirratus), a species of sawshark found in the eastern Indian Ocean around southern Australia on the continental shelf at depths of between 40 and 310 m (130 and 1,020 ft). It is a medium-sized shark with a saw-like flattened snout which measures up to thirty percent of its body size.
A discus (Symphysodon discus) is guarding its eggs. As for most cichlids, brood care is highly developed with both the parents caring for the young. Additionally, adult discus produce a secretion through their skin, off which the larvae live during their first few days.
The leopard shark (Triakis semifasciata) is a species of hound shark found along the Pacific coast of North America from the U.S. state of Oregon to Mazatlán in Mexico. Typically measuring 1.2–1.5 m (3.9–4.9 ft) long, this slender-bodied shark is characterized by black saddle-like markings and large spots over its back.
The Siamese fighting fish (Betta splendens), or fighting betta is a freshwaterfish related to the paradise fish. The fighting fish is a species in the Gourami family which is popular as an aquarium fish. They are called pla-kad (biting fish) in Thai or trey krem in Khmer. They are a very territorial fish and it is unwise to house two males together. Even the females may become territorial towards each other if not housed in a large enough tank.
The spotted trunkfish (Lactophrys bicaudalis) is a species of ray-finned fish in the family Ostraciidae, native to the Caribbean Sea and parts of the western Atlantic Ocean. Members of this family are known as boxfishes because they have a hard outer covering consisting of hexagonal, plate-like scales fused together into a solid, triangular or box-like carapace. Because of this casing, the body of the spotted trunkfish is not flexible, and locomotion is normally limited to slow movements performed by rippling its dorsal and anal fins and gently beating its pectoral fins. If faster motion is required, it can additionally use its caudal fin for propulsion. This spotted trunkfish was photographed at a depth of about 40 ft (12 m) at Bari Reef, Bonaire.
The flying gurnard is a fish of tropical to warm temperate waters on both sides of the Atlantic Ocean. When excited, it spreads its "wings", semi-transparent appendages tipped with a phosphorescent bright blue coloration which are used to frighten predators.
The Eurasian ruffe (Gymnocephalus cernua) is a species of freshwater fish found in temperate regions of Europe and Asia. The aggressive fish is known to reproduce rapidly, leading to problems when it is introduced to foreign bodies of water.
The Oscar (Astronotus ocellatus) is a species of fish from the cichlidfamily. In South America, where the species occurs, they are often found for sale as a food fish in the local markets. The species is also a popular aquarium fish. They have been reported to grow to a length of 45 cm (ca. 18 in) and a mass of 1.6 kg (3.5 lb).
The Peacock flounder (Bothus mancus) is a species of lefteye flounder found widely in relatively shallow waters in the Indo-Pacific. This photomontage shows four separate views of the same fish, each several minutes apart, starting from the top left. Over the course of the photos, the fish changes its colors to match its new surroundings, and then finally (bottom right) buries itself in the sand, leaving only the eyes protruding.
The orbicular batfish (Platax orbicularis) is a batfish endemic to the Indian and Pacific Oceans. It has a thin, disc-shaped body, and male can grow up to 50 centimetres (20 in) in length. In the wild, the orbicular batfish lives in brackish or marine waters, usually around reefs, at depths from 5 to 30 metres (20 to 100 ft). It is also a popular aquarium fish, although captive specimens generally do not grow as long as wild ones.
An Atlantic salmon (Salmo salar) egg hatching. The Alevin (larva) has grown around the remains of the yolk sac - visible are the arteries spinning around the yolk and little oildrops, also the gut, the spine, the main caudalblood vessel, the bladder and the arcs of the gills. In about 24 hours it will be a fry without yolk sac.
In American English, the name gar (or garpike) is strictly applied to members of the Lepisosteidae, a family including seven living species of fish in two genera that inhabit fresh, brackish, and occasionally marine, waters of eastern North America, Central America, and the Caribbean islands.
A plate with fossils of Pseudostacus sp. (lobster, left) and Diplomystus birdii (fish, right), from the Hakel paleontological formation in Lebanon. The paleontological sites of Lebanon contain deposits of some of the best-preserved fossils in the world, and include some species found nowhere else. The most famous of these is the Lebanese lagerstätten of the Late Cretaceous age.
Mudskippers, such as this Periophthalmodon septemradiatus, are uniquely adapted to a completely amphibious lifestyle. They are active when out of water, feeding and interacting with one another, as well as defending their territories.
The Mini Edition of the Fish Portal is available for you to use on your wikipedia user page or talk page. It uses minimum space but retains many crucial features of the portal. To use it, place {{Portal:Fish/Mini portal}} on the designated page. See here for an example of the mini portal on a user page.
The Fish Quiz is a friendly quiz competition designed to test your general knowledge of fish. The current game is Fish Quiz Tournament X. You can read more and join the game here.
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