Atlantic stargazer | |
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Atlantic stargazer from the Black Sea | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Trachiniformes |
Family: | Uranoscopidae |
Genus: | Uranoscopus |
Species: | U. scaber |
Binomial name | |
Uranoscopus scaber | |
Synonyms [2] | |
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The Atlantic stargazer (Uranoscopus scaber) is a marine, subtropical fish of family Uranoscopidae. Its body is suited for living on the sea floor, and is one of few fish capable of bioelectrogenesis, or the ability to generate an electric charge.
It is widespread along the Atlantic coast of Europe and Africa, is very common in the Mediterranean and Black Sea, and somewhat rare in the Bay of Biscay. [3] It is a demersal fish, which lives in sandy or muddy sand sediments along the upper slope of the continental shelf, between depths of 14–400 meters. [4] It is not an economically important fish, primarily caught as by-catch, but is ecologically important. [5]
Typical of stargazers, its body is somewhat dorso-ventrally flattened, lacks a swimbladder, [6] and has been found as large as 35.0 centimeters in length, but is usually between 20 and 30 cm. [5] Its head and jaws are rotated upward, and has very large eyes and mouth. Its body is brown in color and can have numerous small light spots, with a lighter belly. It lives to about 5 or 6 years, and females are larger in size than males. [7]
Like other stargazers, it is an ambush predator which lies buried under sand with only its eyes showing. It has a large mouth, with a small strip of skin protruding from its lower jaw, which it moves in and out rapidly to act as a lure for prey. When a prey item comes near, the fish lunges toward the prey using a specially adapted vertebral column to generate the force by bending 60°, which takes less than 30 milliseconds to engulf the prey. [8] It feeds primarily on fish larvae and smaller fishes, such as gobies, picarels, and small crustaceans, [9] but has also been known to eat molluscs, echinoderms, annelids, algae and plant material. [10]
They can spawn between April and September, depending on the region, and produce pelagic eggs, about 2 millimeters in diameter. After hatching, the larvae, post-larvae, and juveniles remain pelagic. Males are slightly more common than females, but this can vary within local populations. [4]
All species within the genus Uranoscopus , along with those in Astroscopus , have evolved electric organs, but lack receptor organs. These were both independently evolved, and are the only two genera within the order Perciformes to produce electric organ discharges (EODs). The Atlantic stargazer, like other bioelectrogenic stargazers, produces pulse-type EODs while feeding and when it is disturbed. The Atlantic stargazer produces EODs with the electric organ, derived from sonic muscles. [11] In other fishes, sonic muscles are used to produce sound by agitating the swim bladder.
The stargazers are a family, Uranoscopidae, of perciform fish that have eyes on top of their heads. The family includes about 51 species in eight genera, all marine and found worldwide in shallow and deep saltwaters.
An electric fish is any fish that can generate electric fields. Most electric fish are also electroreceptive, meaning that they can sense electric fields. The only exception is the stargazer family (Uranoscopidae). Electric fish, although a small minority, include both oceanic and freshwater species, and both cartilaginous and bony fishes.
The black ghost knifefish is a tropical fish belonging to the ghost knifefish family (Apteronotidae). They originate in freshwater habitats in South America where they range from Venezuela to the Paraguay–Paraná River, including the Amazon Basin. They are popular in aquaria. The fish is all black except for two white rings on its tail, and a white blaze on its nose, which can occasionally extend into a stripe down its back. It moves mainly by undulating a long fin on its underside. It will grow to a length of 18"-20". Only a fish for those with large aquariums, minimum 100 gallons.
Sabertooth or sabretooth fish are small, fierce-looking deep-sea aulopiform fish comprising the family Evermannellidae. The family is small, with just eight species in three genera represented; they are distributed throughout tropical to subtropical waters of the Atlantic, Indian, and Pacific Oceans.
Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes. They occupy the sea floors and lake beds, which usually consist of mud, sand, gravel or rocks. In coastal waters they are found on or near the continental shelf, and in deep waters they are found on or near the continental slope or along the continental rise. They are not generally found in the deepest waters, such as abyssal depths or on the abyssal plain, but they can be found around seamounts and islands. The word demersal comes from the Latin demergere, which means to sink.
The largehead hairtail or beltfish is a member of the cutlassfish family, Trichiuridae. This common to abundant species is found in tropical and temperate oceans throughout the world. The taxonomy is not fully resolved, and the Atlantic, East Pacific and Northwest Pacific populations are also known as Atlantic cutlassfish, Pacific cutlassfish and Japanese cutlassfish, respectively. This predatory, elongated fish supports major fisheries.
The greater weever is a benthic and demersal venomous marine fish of the family Trachinidae. The greater weever is widely distributed along the eastern Atlantic coastline from Norway to Morocco, extending to the Mediterranean, Aegean and Black Seas. Trachinus draco has been shown to occur in depths ranging from shallow water up to -150 meters where it inhabits mostly muddy or sandy grounds. Trachinus draco is mostly and notoriously known for its venomous spines that can inflict serious injuries on humans through accidental stinging. Because of these spines and its potent venom it is classified as one of the most venomous fishes in the Mediterranean. The name “weever” is thought to originate from the Anglo-Saxon word “wivre” which translates as “viper”.
Scorpaena is a widespread genus of marine ray-finned fish belonging to the family Scorpaenidae, the scorpionfishes.
Mullus barbatus is a species of goatfish found in the Mediterranean Sea, Sea of Marmara, the Black Sea and the eastern North Atlantic Ocean, where its range extends from Scandinavia to Senegal. They are fished, mostly by trawling, with the flesh being well regarded. The International Union for Conservation of Nature has assessed their conservation status as being of "least concern".
The marbled electric ray is a species of electric ray in the family Torpedinidae 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.
A bottom feeder is an aquatic animal that feeds on or near the bottom of a body of water. Biologists often use the terms benthos—particularly for invertebrates such as shellfish, crabs, crayfish, sea anemones, starfish, snails, bristleworms and sea cucumbers—and benthivore or benthivorous, for fish and invertebrates that feed on material from the bottom. However the term benthos includes all aquatic life that lives on or near the bottom, which means it also includes non-animals, such as plants and algae. Biologists also use specific terms that refer to bottom feeding fish, such as demersal fish, groundfish, benthic fish and benthopelagic fish. Examples of bottom feeding fish species groups are flatfish, eels, cod, haddock, bass, grouper, carp, bream (snapper) and some species of catfish, sharks.
The tub gurnard, also known as the sapphirine gurnard, tube-fish, tubfish or yellow gurnard, is a species of marine ray-finned fish belonging to the family Triglidae, the gurnards and sea robins. It is found in the eastern Atlantic Ocean. It is exploited by commercial fisheries as a food fish.
The common torpedo, also known as ocellate torpedo or eyed electric ray, is a species of electric ray in the family Torpedinidae. It is found in the Mediterranean Sea and the eastern Atlantic Ocean from the Bay of Biscay to Angola, and is a benthic fish typically encountered over soft substrates in fairly shallow, coastal waters. Growing to 60 cm (24 in) long, this species has a nearly circular pectoral fin disc and a short, thick tail with two dorsal fins of nearly equal size and a large caudal fin. It can be identified by the prominent blue spots on its back, which usually number five but may vary from zero to nine, as well as by the small knobs on the rims of its spiracles.
The Mediterranean parrotfish is a species of parrotfish found at depths up to 50 m (160 ft) along rocky shores in the Mediterranean and the eastern Atlantic, from Portugal south to Senegal. It is generally common, but uncommon or rare in the northwestern Mediterranean and in the Adriatic Sea. It prefers relatively warm temperatures and there is an ongoing northward range expansion, probably because of global warming. The primary adult habitat is rocky reefs, especially in areas with macroalgae, but they may visit adjacent seagrass patches. Juveniles also occur more widely in the latter habitat.
The torpedo scad, also known as the hardtail scad, finny scad, finletted mackerel scad or cordyla scad, is a species of moderately large marine fish classified in the jack and horse mackerel family, Carangidae. The torpedo scad is distributed throughout the tropical Indo-Pacific region, ranging from South Africa in the west to Tonga in the east, extending to Japan in the north and Australia in south. It is a schooling pelagic fish which occupies the surface layers of both inshore and offshore oceanic waters. The torpedo scad is easily identified by both its 'torpedo' shaped body and a series of detached finlets at the rear of both the dorsal and anal fins. The largest recorded individual was 80 cm long and weighed 4 kg, although it is more common at lengths less than 40 cm. It is a predatory species, taking a variety of fish, cephalopods and crustaceans by both active and filter feeding. There is a shift in diet as the species grow; however fish is the dominant prey in all size classes. Torpedo scad reach sexual maturity at 22 cm in females and 26.4 cm in males, with spawning occurring between March and July in India, where significant research into larval growth and morphometrics has been carried out.
The common dragonet is a species of dragonet which is widely distributed in the eastern North Atlantic where it is common near Europe from Norway and Iceland southwards. It is a demersal species that occurs over sand bottoms. It lives to a maximum age of around seven years. It is caught in bycatch by fisheries and is used in the aquarium trade.
Uranoscopus is a genus of stargazer fish from the family Uranoscopidae. The name Uranoscopus is from the Greek, ouranos, "sky" and skopein, "to watch".
Dollfus' stargazer is a fish of the family Uranoscopidae, widespread in the Western Indian Ocean: Gulf of Suez, Gulf of Oman, and Persian Gulf. It is a marine demersal fish, and occurs at depths down to about 46 metres (151 ft). It was named in honour of Dr R. P. Dollfus who led an expedition to Egypt in 1928–1929 and who brought back some specimens of this fish which he mistakenly identified as Uranoscopus affinis. These were new to science and became the type specimens of the new species U. dollfusi, with the Gulf of Suez being the type locality.
Uranoscopus brunneus, the dark-finned stargazer, is a member of the group Uranoscopidae, the benthic living fishes distributed worldwide in tropical and temperate oceans.
The rough ray is a Mediterranean ray species of the Rajidae family described by Delaroche in 1809.