Portal:Fish

The sicklefin weasel shark (Hemigaleus microstoma) is an uncommon species of ground shark in the family Hemigaleidae. It is native to southern India, southern China, and parts of Southeast Asia, living in shallow waters down to a depth of 170 m (560 ft). This lightly built shark is characterized by its very short mouth, broad upper teeth with serrations only on the trailing edge, and strongly sickle-shaped fins with obvious white tips on the two dorsal fins. It is light grey or bronze in colour, often with small white blotches on its sides; it reaches a maximum known length of 1.1 m (3.6 ft).

Spending most of its time close to the sea floor, the sicklefin weasel shark is a specialist predator of cephalopods. Its reproductive mode is viviparous, in which the unborn young form a placental connection to their mother. Females probably give birth twice a year, with each litter consisting of two to four pups. The sicklefin weasel shark is widely caught by artisanal fisheries and used for meat, fins, and fishmeal; its low natural abundance and reproductive rate mean that it cannot sustain much fishing pressure. Given that fishing activity is intense throughout its range, the International Union for Conservation of Nature (IUCN) has assessed this species as vulnerable. (Full article...)

Stephanolepis cirrhifer, commonly known as the thread-sail filefish, is a species of marine fish in the family Monacanthidae. It is found in the western Pacific, in an area that ranges from northern Japan to the East China Sea, to Korea. The fish grows to a maximum length of about 12 inches (30 centimetres), and consumes both plant material and small marine organisms like skeleton shrimp. S. cirrhifer is host of the parasite Peniculus minuticaudae. Some minor genetic differentiation between S. cirrhifer born in the wild and those bred in a hatchery for consumer use has been shown. The fish is edible and sold commercially for culinary purposes in many Asian countries. (Full article...)

The coral catshark (Atelomycterus marmoratus) is a species of coloured catshark belonging to the family Atelomycteridae. It is common on shallow coral reefs across the Indo-West Pacific, from Pakistan to New Guinea. Reaching up to 70 cm (28 in) in length, the coral catshark has an extremely slender body, a short head and tail, and two dorsal fins that are angled backwards. It can be identified by the numerous black and white spots on its back, sides, and fins, which often merge to form horizontal bars. Furthermore, adult males have distinctively long and thin claspers.

Reclusive and inactive during the day, at dusk and at night, the coral catshark actively forages for small, bottom-living invertebrates and bony fishes. Its slender form allows it to access tight spaces on the reef. It is oviparous; females lay purse-shaped egg capsules two at a time on the bottom, and the young hatch after 4–6 months. This small, harmless shark adapts well to captivity and has reproduced in the aquarium; it is regarded as one of the most suitable shark species for private aquarists. The coral catshark is a minor bycatch of reef fisheries, with minimal commercial value. Increasing fishing activity and extensive habitat degradation occur within its range, leading to concern over its population and its assessment as near threatened by the International Union for Conservation of Nature. (Full article...)

The zebra shark (Stegostoma tigrinum), also known as the Indo-Pacific leopard shark, is a species of carpet shark and the only extant member of the family Stegostomatidae. It is found throughout the tropical Indo-Pacific, frequenting coral reefs and sandy flats to a depth of 62 m (200 ft). Zebra sharks are distinctive in appearance, with adults possessing five longitudinal ridges on a cylindrical body, a low caudal fin comprising nearly half the total length, and typically a pattern of dark spots on a pale background. Young zebra sharks under 50–90 cm (20–35 in) long have a completely different pattern, consisting of light vertical stripes on a brown background, and lack the ridges. This species attains a length of 2.5 m (8.2 ft).

Zebra sharks are nocturnal and spend most of the day resting motionless on the sea floor. At night, they actively hunt for molluscs, crustaceans, small bony fishes, and possibly sea snakes inside holes and crevices in the reef. Though solitary for most of the year, they form large seasonal aggregations. The zebra shark is oviparous: females produce several dozen large egg capsules, which they anchor to underwater structures via adhesive tendrils. Innocuous to humans and hardy in captivity, zebra sharks are popular subjects of ecotourism dives and public aquaria. The World Conservation Union has assessed this species as Endangered worldwide, as it is taken by commercial fisheries across most of its range (except off Australia) for meat, fins, and liver oil. There is evidence that its numbers are dwindling. (Full article...)

The spinner shark (Carcharhinus brevipinna) is a type of requiem shark, in the family Carcharhinidae, named for the spinning leaps it makes as a part of its feeding strategy. This species occurs in tropical and warm temperate waters worldwide, except for in the eastern Pacific Ocean. It is found from coastal to offshore habitats to a depth of 100 m (330 ft), though it prefers shallow water. The spinner shark resembles a larger version of the blacktip shark (C. limbatus), with a slender body, long snout, and black-marked fins. This species can be distinguished from the blacktip shark by the first dorsal fin, which has a different shape and is placed further back, and by the black tip on the anal fin (in adults only). It attains a maximum length of 3 m (9.8 ft).

Spinner sharks are swift and gregarious predators that feed on a wide variety of small bony fishes and cephalopods. When feeding on schools of forage fish, they speed vertically through the school while spinning on their axis, erupting from the water at the end. Like other members of its family, the spinner shark is viviparous, with females bearing litters of three to 20 young every other year. The young are born in shallow nursery areas near the coast, and are relatively fast-growing. This species is not usually dangerous to humans, but may become belligerent when excited by food. Spinner sharks are valued by commercial fisheries across their range for their meat, fins, liver oil, and skin. They are also esteemed as strong fighters by recreational fishers. The International Union for Conservation of Nature has assessed this species as Vulnerable worldwide. (Full article...)

The Sacred Cod is a four-foot-eleven-inch (150 cm) carved-wood effigy of an Atlantic codfish, painted to the life, hanging in the House of Representatives chamber of Boston's Massachusetts State House‍—‌"a memorial of the importance of the Cod-Fishery to the welfare of this Commonwealth"
(i.e. Massachusetts, of which cod is officially the "historic and continuing symbol").
The Sacred Cod has gone through as many as three incarnations over three centuries: the first
(if it really existed‍—‌the authoritative source calling it a "prehistoric creature of tradition")
was lost in a 1747 fire; the second disappeared during the American Revolution; and the third, installed in 1784, is the one seen in the House chamber today.

"Sacred Cod" is not a formal name but a nickname which appeared in 1895, soon after the carving was termed "the sacred emblem" by a House committee appointed "to investigate the significance of the emblem [which] has kept its place under all administrations, and has looked upon outgoing and incoming legislative assemblies, for more than one hundred years".^{[C]: 3–4, 12} Soon sacred cod was being used in reference to actual codfish as well, in recognition of the creature's role in building Massachusetts's prosperity and influence since early colonial times. (Full article...)

The Australian blacktip shark (Carcharhinus tilstoni) is a species of requiem shark, in the family Carcharhinidae, endemic to northern and eastern Australia. Favoring the upper and middle parts of the water column, it can be found from the intertidal zone to a depth of 50 m (160 ft). Appearance-wise this species is virtually identical to the common blacktip shark (C. limbatus), from which it can be reliably distinguished only by its lower vertebra number and by genetic markers. Generally reaching 1.5–1.8 m (4.9–5.9 ft) in length, it is a fairly stout-bodied, bronze-colored shark with a long snout and black-tipped fins.

Primarily piscivorous, the Australian blacktip shark forms large groups of similar size and sex that tend to remain within a local area. It exhibits viviparity, meaning that the unborn young are provisioned through a placental connection. There is a well-defined annual reproductive cycle with mating occurring in February and March. Females bear one to six pups around January of the following year, after a 10-month gestation period. The Australian blacktip shark is among the sharks most commonly caught by northern Australian commercial fisheries. It is mainly valued for its meat, which is sold as "flake". This species was an important catch of a Taiwanese gillnet fishery that operated from 1974 to 1986, and of the Australian Northern Shark Fishery that continues to the present day. As current fishing levels are not thought to threaten this shark's population, the International Union for Conservation of Nature (IUCN) has assessed it as Least Concern. (Full article...)

The leopard shark (Triakis semifasciata) is a species of houndshark, in the family Triakidae. It is 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 immediately identifiable by the striking pattern of black saddle-like markings and large spots over its back, from which it derives its common name. Large schools of leopard sharks are a common sight in bays and estuaries, swimming over sandy or muddy flats or rock-strewn areas near kelp beds and reefs. They are most common near the coast, in water less than 4 m (13 ft) deep.

Active-swimming predators, groups of leopard sharks often follow the tide onto intertidal mudflats to forage for food, mainly clams, spoon worms, crabs, shrimp, bony fish, and fish eggs. Most leopard sharks tend to remain within a particular area rather than undertaking long movements elsewhere, which has led to genetic divergence between populations of sharks living in different regions. This species is aplacental viviparous, meaning that the young hatch inside the uterus and are nourished by yolk. From March to June, the female gives birth to as many as 37 young after a gestation period of 10–12 months. It is relatively slow-growing and takes many years to mature. (Full article...)

The Cape Fear shiner (Notropis mekistocholas) is a species of freshwater ray-finned fish in the family Leuciscidae, the shiners, daces and minnows. It is endemic to the central part of the state of North Carolina in the southeastern United States, and is only found in the shallow streams of the Cape Fear River basin. The fish is small and yellow with black lips and a black stripe that runs down the middle of the fish's side. This shiner is normally found in mixed schools with other minnow species. It is unique amongst its genus because it has elongated intestines that are specifically adapted to a primarily herbivorous diet. It can breed twice a year and normally lives for only two or three years in the wild. The males and females are normally similar in appearance but become different colors in the spawning season. This species of shiner was not discovered until 1962.

As of 2013, the shiner is endangered, according to the International Union for Conservation of Nature, due to its small population size and threats to its habitat from dam construction and pollution. It was previously listed as critically endangered by the IUCN in 1996. The species has since undergone a successful captive breeding program, and its status has been a significant factor in the destruction of a dam that destroyed part of the shiner's habitat. However, the species is still limited to just five populations in the wild, and some experts^[who?] believe that a single toxic chemical spill into the Cape Fear River could wipe out the entire wild population. (Full article...)

Tetronarce californica also known as the Pacific electric ray is a species of electric ray in the family Torpedinidae, endemic to the coastal waters of the northeastern Pacific Ocean from Baja California to British Columbia. It generally inhabits sandy flats, rocky reefs, and kelp forests from the surface to a depth of 200 m (660 ft), but has also been known to make forays into the open ocean. Measuring up to 1.4 m (4.6 ft) long, this species has smooth-rimmed spiracles (paired respiratory openings behind the eyes) and a dark gray, slate, or brown dorsal coloration, sometimes with dark spots. Its body form is typical of the genus, with a rounded pectoral fin disc wider than long and a thick tail bearing two dorsal fins of unequal size and a well-developed caudal fin.

Solitary and nocturnal, the Pacific electric ray can generate up to 45 volts of electricity for the purposes of subduing prey or self-defense. It feeds mainly on bony fishes, ambushing them from the substrate during the day and actively hunting for them at night. Reproduction is aplacental viviparous, meaning that the embryos are initially nourished by yolk, later supplemented by histotroph ("uterine milk") produced by the mother. Females bear litters of 17–20 pups, probably once every other year. Care should be exercised around the Pacific electric ray, as it has been known to act aggressively if provoked and its electric shock can potentially incapacitate a diver. It and other electric rays are used as model organisms for biomedical research. The International Union for Conservation of Nature (IUCN) has listed this species under Least Concern, as it is not fished in any significant numbers. (Full article...)

The crocodile shark (Pseudocarcharias kamoharai) is a species of mackerel shark and the only extant member of the family Pseudocarchariidae. A specialized inhabitant of the mesopelagic zone, the crocodile shark can be found worldwide in tropical waters from the surface to a depth of 590 m (1,940 ft). It performs a diel vertical migration, staying below a depth of 200 m (660 ft) during the day and ascending into shallower water at night to feed. Typically measuring only 1 m (3.3 ft) in length, the crocodile shark is the smallest living mackerel shark. It can be distinguished by its elongated cigar-shaped body, extremely large eyes, and relatively small fins.

An active-swimming predator of pelagic bony fishes, squid and shrimp, the crocodile shark has a sizable oily liver that allows it to maintain its position in the water column with minimal effort. The size and structure of its eyes suggests that it is adapted for hunting at night. The crocodile shark is aplacental viviparous, with females typically giving birth to litters of four. The fetuses are oophagous, meaning that they feed on undeveloped eggs ovulated for this purpose by their mother. Due to its small size, the crocodile shark poses little danger to humans and is of little commercial importance. This species was responsible for damaging deep sea fiberoptic cables when the technology was first deployed in 1985. In 2017, one crocodile shark was spotted by a family walking on a UK beach. (Full article...)

The barndoor skate (Dipturus laevis) is a species of marine cartilaginous fish in the skate family Rajidae of the order Rajiformes. It is native to the northwestern Atlantic Ocean, and is found from the Grand Banks of Newfoundland and the southern side of the Gulf of St. Lawrence south to North Carolina. The fish is one of the largest skates found in the North Atlantic Ocean, reaching lengths up to 1.5 m (5 ft). It is carnivorous, feeding on invertebrates and other fish found near the sea floor.

After peaking in the 1950s, the population of the barndoor skate dramatically declined in the 1960s and early 1970s as a result of overfishing. In 2003, it was listed as endangered by the World Conservation Union. However, barndoor skate populations have increased substantially since 1990 and even surpassed 1960s population size by 2012. In 2019, the barndoor skate was downlisted to least concern by the IUCN based on its largely increased population, new protections within its range, and also minor expansions to its range. In most cases, the barndoor skate is not intentionally harvested by the commercial fishing industry—it is usually considered bycatch in the trawling nets used to target other species of fish. (Full article...)

The Devils Hole pupfish (Cyprinodon diabolis) is a critically endangered species of the family Cyprinodontidae (pupfishes) found only in Devils Hole, a water-filled cavern in the US state of Nevada. It was first described as a species in 1930 and is most closely related to C. nevadensis and the Death Valley pupfish (C. salinus). The age of the species is unknown, with differing analyses offering ranges between one thousand and sixty thousand years. It is a small fish, with maximum lengths of up to 30 mm (1.2 in). Individuals vary in coloration based on age and sex: males are bright metallic blue while females and juveniles are more yellow. A defining trait of this species is its lack of pelvic fins. The pupfish consumes nearly every available food resource at Devils Hole, including beetles, snails, algae, and freshwater crustaceans, with diet varying throughout the year. It is preyed on by the predaceous diving beetle species Neoclypeodytes cinctellus, which was first observed in Devils Hole in 1999 or 2000. Reproduction occurs year-round, with spikes in the spring and fall. Females produce few eggs and the survivorship from egg to adult is low. Individuals live 10–14 months.

Devils Hole is more than 130 m (430 ft) deep, though pupfish are only found in the upper 24 m (80 ft). The water is a constant temperature of 33 °C (91 °F) and dissolved oxygen levels are low. A small, shallowly submerged rock shelf provides critical feeding and spawning habitat for the pupfish. Nearby agricultural irrigation in the 1960s and 1970s caused the water to drop in Devils Hole, resulting in less and less of the shelf remaining submerged. Several court cases ensued, resulting in the Supreme Court case Cappaert v. United States, which determined that the preservation of Devils Hole as a National Monument in 1952 implicitly included preservation of adequate groundwater to maintain the scientific value of the pool and its fauna. Other threats faced by the species include flash floods, earthquakes, and vandalism. (Full article...)

Clarias ngamensis, known as the blunt-toothed African catfish, is a species of freshwater fish in the family Clariidae, the airbreathing catfishes. First described by François-Louis Laporte, comte de Castelnau in 1861, the fish is found in swamps and floodplains in much of southern Africa. It reaches a maximum size of 73 centimetres (29 in) in total length and 4.0 kilograms (8.8 lb). The fish can breathe air and survive out of water for extended periods. Its diet includes molluscs, insects, and crabs. This species is fished and farmed for human consumption. (Full article...)

Manta rays are large rays belonging to the genus Mobula (formerly its own genus Manta). Three species are known: M. birostris, the largest at 7 m (23 ft) in width, M. yarae, which reaches 6 m (20 ft), and M. alfredi, the smallest at 5.5 m (18 ft). All three have triangular pectoral fins, horn-shaped cephalic fins and large, forward-facing mouths. They are classified among the Myliobatiformes (stingrays and relatives) and are placed in the family Myliobatidae (eagle rays). They have one of the highest brain-to-body ratio of all fish, advanced cognition, and may understand mirror contingencies.

Mantas are found in warm temperate, subtropical and tropical waters. All three species are pelagic; M. birostris and M. yarae migrate across open oceans, singly or in groups, while M. alfredi tends to be resident and coastal. They are filter feeders and eat large quantities of zooplankton, which they gather with their open mouths as they swim. However, research suggests that the majority of their diet comes from mesopelagic sources. Gestation lasts over a year and mantas give birth to live pups. Mantas may visit cleaning stations for the removal of parasites. Like whales, they breach for unknown reasons. (Full article...)