Banded houndshark | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Chondrichthyes |
Subclass: | Elasmobranchii |
Subdivision: | Selachimorpha |
Order: | Carcharhiniformes |
Family: | Triakidae |
Genus: | Triakis |
Species: | T. scyllium |
Binomial name | |
Triakis scyllium J. P. Müller & Henle, 1839 | |
Range of the banded houndshark [2] | |
Synonyms | |
Hemigaleus pingiEvermann & Shaw, 1927 |
The banded houndshark (Triakis scyllium) is a species of houndshark in the family Triakidae, common in the northwestern Pacific Ocean from the southern Russian Far East to Taiwan. Found on or near the bottom, it favors shallow coastal habitats with sandy or vegetated bottoms, and also enters brackish water. This shark reaches 1.5 m (4.9 ft) in length. It has a short, rounded snout and mostly narrow fins; the pectoral fins are broad and triangular, and the trailing margin of the first dorsal fin is almost vertical. It is gray above and lighter below; younger sharks have darker saddles and dots, which fade with age.
Nocturnal and largely solitary, the banded houndshark preys on benthic invertebrates and bony fishes. It is aplacental viviparous, with the developing embryos sustained by yolk. After mating during summer, females bear as many as 42 pups following a gestation period of 9–12 months. The banded houndshark poses no danger to humans and adapts well to captivity. It is caught as bycatch off Japan, Taiwan, and likely elsewhere in its range; it may be eaten but is not as well-regarded as related species. Because fishing does not appear to have diminished this shark's population, the International Union for Conservation of Nature has listed it under Endangered.
The first scientific description of the banded houndshark was authored by German biologists Johannes Peter Müller and Friedrich Gustav Jakob Henle, based on a dried specimen from Japan, in their 1838–41 Systematische Beschreibung der Plagiostomen. They gave it the specific epithet scyllium, derived from the Ancient Greek skylion ("dogfish"), and placed it in the genus Triakis. [3] Within the genus, it is placed in the subgenus Triakis along with the leopard shark (T. (Triakis) semifasciata). [2]
Native to the northwestern Pacific Ocean, the banded houndshark occurs from the southern Russian Far East to Taiwan, including Japan, Korea, and eastern China; records from the Philippines are questionable. [1] This common, benthic shark is found over continental and insular shelves, mostly close to shore, but also to a depth of 150 m (490 ft). [4] It frequents sandy flats and beds of seaweed and eelgrass; additionally, it is tolerant of brackish water and enters estuaries and bays. [1]
The banded houndshark is a moderately slender-bodied species growing up to 1.5 m (4.9 ft) long. The snout is short, broad, and rounded; the widely separated nostrils are each preceded by a lobe of skin that does not reach the mouth. The horizontally oval eyes are placed high on the head; they are equipped with rudimentary nictitating membranes (protective third eyelids) and have prominent ridges underneath. The mouth forms a short, wide arch and bears long furrows at the corners that extend onto both jaws. Each tooth has an upright to oblique knife-like central cusp flanked by strong cusplets. There are five pairs of gill slits. [2]
Most of the fins are fairly narrow; in adults the pectoral fins are broad and roughly triangular. The moderately tall first dorsal fin is placed about halfway between the pectoral and pelvic fins, and its trailing margin is nearly vertical near the apex. The second dorsal fin is about three-quarters as high as the first and larger than the anal fin. The caudal fin has a well-developed lower lobe and a prominent ventral notch near the tip of the upper lobe; in young sharks the lower caudal fin lobe is much less distinct. [2] This species is gray above, with darker saddles and scattered black spots that fade with age; the underside is off-white. [4]
The banded houndshark is nocturnal and generally solitary, though several individuals may rest together, sometimes piled atop one another inside a cave. [4] [5] It feeds mainly on crustaceans (including shrimp, crabs, hermit crabs, and mantis shrimp), cephalopods (including octopus), and spoon worms; polychaete worms, tunicates, peanut worms, and small, bottom-living bony fishes (including flatfishes, conger eels, herring, jacks, drums, and grunts) are occasionally consumed. Shrimp and spoon worms are important prey for sharks up to 70 cm (28 in) long; cephalopods predominate in the diets of larger sharks. [6]
Mating occurs during the summer, and involves the male swimming parallel to the female and gripping her pectoral fin with his teeth; thus secured, he then twists the distal portion of his body to insert a single clasper into her cloaca for copulation. The banded houndshark is aplacental viviparous, in which the developing embryos are sustained to birth by yolk. Females bear litters of 9–26 pups after a gestation period of 9–12 months, though litters as large as 42 pups have been recorded. [5] [7] [8]
In 2016, at the Uozu Aquarium in Japan, two puppies were born in a tank with only females, and parthenogenesis was confirmed. [9]
The newborns measure 18–20 cm (7.1–7.9 in) long. Males mature sexually at 5–6 years old, when they are 93–106 cm (37–42 in) long, and live up to 15 years. Females mature sexually at 6–7 years old, when they are 106–107 cm (42–42 in) long, and live up to 18 years. [1] Known parasites of this species include the tapeworms Callitetrarhynchus gracilis, [10] Onchobothrium triacis, and Phyllobothrium serratum, [11] the leech Stibarobdella macrothela, [12] and the copepods Achtheinus impenderus, [13] Caligus punctatus, [14] Kroyeria triakos, [15] and Pseudopandarus scyllii. [16]
Harmless to humans, [17] the banded houndshark is commonly displayed in public aquariums in China and Japan, [1] and has reproduced in captivity. [8] Individuals have survived in captivity for over five years. [5] This species is often caught incidentally off Japan in gillnets and set nets; the meat is sometimes sold, but is considered to be of poorer quality than that of other houndsharks in the region. It is caught in lesser numbers off Taiwan, and is probably also fished off Korea and northern China. Off Japan, it can be found in rocky areas that provide refuge from fishing pressure. [1]
The dusky smooth-hound, also called the smooth dogfish or the dog shark, is a species of houndshark in the family Triakidae. This shark is an olive grey or brown in color, and may have shades of yellow or grayish white. Females live to 16 years and males have a lifespan of 10 years. M. canis was the first shark recognised to have viral infections.
The Triakidae or houndsharks are a family of ground sharks, consisting of about 40 species in nine genera. In some classifications, the family is split into two subfamilies, with the genera Mustelus, Scylliogaleus and Triakis in the subfamily Triakinae, and the remainders in the subfamily Galeorhininae.
The leopard shark 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.
The horn shark is a species of bullhead shark, in the family Heterodontidae. It is endemic to the coastal waters off the western coast of North America, from California to the Gulf of California. Young sharks are segregated spatially from the adults, with the former preferring deeper sandy flats and the latter preferring shallower rocky reefs or algal beds. A small species typically measuring 1 m (3.3 ft) in length, the horn shark can be recognized by a short, blunt head with ridges over its eyes, two high dorsal fins with large spines, and a brown or gray coloration with many small dark spots.
The blind shark is one of two species of carpet sharks in the family Brachaeluridae, along with the bluegrey carpetshark. Found along the coast of eastern Australia, this nocturnal, bottom-dwelling species is common in rocky areas and seagrass beds from the intertidal zone to a depth of 140 m (460 ft). It often roams in tidal pools where it may be trapped by the receding tide, and can survive for an extended period out of water.
The pygmy ribbontail catshark is a species of finback catshark, family Proscylliidae, distributed patchily in the western Indo-Pacific from Tanzania to the Philippines. It occurs around the edges of continental and insular shelves at a depth of 71–766 m (233–2,513 ft), typically on or near mud bottoms. One of the smallest living shark species, the pygmy ribbontail catshark grows to a maximum known length of 24 cm (9.4 in). It has a slender body with a low, ribbon-like tail fin, and is dark brown in color with blackish dorsal fin markings and tail bands. This shark feeds mainly on bony fishes, followed by crustaceans and then squid. It is aplacental viviparous with females bearing litters of 1–2 relatively large pups. It is of minimal significance to fisheries, being caught as bycatch in some areas.
The blotchy swellshark or Japanese swellshark is a common species of catshark, belonging to the family Scyliorhinidae. The Blotchy swellshark is found at depths of 90–200 m (300–660 ft) in the northwestern Pacific Ocean, from Japan to Taiwan. It is benthic in nature and favors rocky reefs. Reaching 1.4 m (4.6 ft) in length, this thick-bodied shark has a broad head, large mouth, and two unequally-sized dorsal fins positioned far back past the pelvic fins. It can be identified by its dorsal coloration, consisting of seven brown "saddles" and extensive darker mottling on a light tan background. This species has often been confounded with the draughtsboard shark and the Sarawak pygmy swellshark in scientific literature.
The smalleye pygmy shark is a little-known species of squaliform shark in the family Dalatiidae, found in water 150–2,000 m (490–6,560 ft) deep near Japan, the Philippines, and Australia. It migrates vertically daily, spending the day in deep water and the night in shallower water. One of the smallest shark species, the smalleye pygmy shark is known to reach only 22 cm (8.7 in) long. It has a blackish, spindle-shaped body with relatively small eyes, and a spine preceding the first dorsal fin, but not the second. Bioluminescent photophores occur on its underside, which may serve to disguise its silhouette from predators. This species feeds on small squid, krill, shrimp, and bony fishes. It is aplacental viviparous. The International Union for Conservation of Nature has assessed it as Least Concern, citing its wide distribution and lack of threat from fisheries.
The spotted houndshark, Triakis maculata, is a houndshark of the family Triakidae found in tropical waters in the eastern Pacific Ocean off the coast of South America. It usually grows to a length around 180 centimetres (71 in). The reproduction of this houndshark is ovoviviparous, with a litter of 14 pups being found in one female with a birth size of 30 to 40 centimetres. Their diet is believed to consist mainly of crustaceans.
The sharptooth houndshark or spotted gully shark is a species of houndshark in the family Triakidae found in shallow inshore waters from southern Angola to South Africa. Favoring sandy areas near rocky reefs and gullies, it is an active-swimming species that usually stays close to the bottom. This robust shark reaches 1.7 m (5.6 ft) in length and has characteristically large, rounded fins; the pectoral fins in particular are broad and sickle-shaped in adults. It also has a short, blunt snout and long furrows around its mouth. This species is gray or bronze in color above, with variable amounts of black spotting.
The sand devil or Atlantic angel shark is a species of angelshark, family Squatinidae, native to the northwestern Atlantic Ocean. It occurs off the eastern United States, in the northern Gulf of Mexico, and possibly in parts of the Caribbean Sea. This bottom-dwelling shark is found in shallow inshore waters in summer and fall, and deep offshore waters in winter and spring. The sand devil's flattened body and enlarged pectoral and pelvic fins give it a ray-like appearance. There is a band of enlarged thorns running along the middle of its back. It is gray or brown in color, with scattered small dark spots. This species reaches 1.2–1.5 m (3.9–4.9 ft) in length.
The speckled smooth-hound is a houndshark of the family Triakidae. It is found on the continental shelf of the eastern Pacific, between latitudes 0° and 54° S, at depths between 16 and 50 m. It can reach a length of 130 cm (51 in). Collectively with certain other species of shark, it is known as "tollo".
The humpback smooth-hound is a species of houndshark and a part of the family Triakidae.The most noticeable difference between Mustelus whitneyi and its relatives, is the slight curvature, causing a "humpback" appearance located in front of its primary dorsal fin. It is found on the continental shelves of the tropical southeast Pacific, from Peru to southern Chile, between latitudes 3° S and 54° S. These sharks are demersal feeders but range from depths between 15 and 210 metres. Humpback smooth-hound sharks are small sharks, reaching a maximum size of 118cm in total length. Mustelus whitneyi typically feed on teleosts and invertebrates in the benthic and pelagic ecosystems, most important prey being the peruvian anchovy. These humpback smooth-hound sharks are placental viviparious sharks, meaning that the embryo forms inside the mother tethered by the placental cord. The threats currently causing population decline to humpback smooth-hound sharks surround issues with local fisheries and management.
The Japanese angelshark is a species of angelshark, family Squatinidae, found in the northwestern Pacific Ocean off China, Japan, and Korea. It is a bottom-dwelling shark found in sandy habitats down to 300 m (980 ft) deep. This species has the flattened shape with wing-like pectoral and pelvic fins typical of its family, and grows to 1.5 m (4.9 ft) or more in length. Its two dorsal fins are placed behind the pelvic fins, and a row of large thorns occurs along its dorsal midline. Its upper surface is cryptically patterned, with numerous squarish dark spots on a brown background.
Rhina ancylostoma, also known as the bowmouth guitarfish, shark ray or mud skate, is a species of ray and a member of the family Rhinidae. Its evolutionary affinities are not fully resolved, though it may be related to true guitarfishes and skates. This rare species occurs widely in the tropical coastal waters of the western Indo-Pacific, at depths of up to 90 m (300 ft). Highly distinctive in appearance, Rhina ancylostoma has a wide and thick body with a rounded snout and large shark-like dorsal and tail fins. Its mouth forms a W-shaped undulating line, and there are multiple thorny ridges over its head and back. It has a dorsal color pattern of many white spots over a bluish gray to brown background, with a pair of prominent black markings over the pectoral fins. This large species can reach a length of 2.7 m (8.9 ft) and weight of 135 kg (298 lb).
The red stingray is a species of stingray in the family Dasyatidae, found in the northwestern Pacific Ocean off Japan, Korea, and China, and possibly elsewhere. It primarily inhabits shallow, sandy habitats close to shore, and has been known to enter brackish water. The red stingray has a diamond-shaped pectoral fin disc and gains its common name from its bright orange-red underside; there may also be patches of orange at various spots on its upper surface. Most individuals are no more than 1 m (3.3 ft) long.
The western shovelnose stingaree is a common species of stingray in the family Urolophidae, inhabiting shallow sandy flats and seagrass beds off southwestern Australia from Perth to Gulf St Vincent. Growing to 37 cm (15 in) long, this small ray has a rounded pectoral fin disc and a blunt, broadly triangular snout. Its nostrils have enlarged lobes along the outer rims and a skirt-shaped curtain of skin between them with a strongly fringed posterior margin. Its tail ends in a lance-like caudal fin and lacks dorsal fins and lateral skin folds. This species is colored grayish to brownish above, sometimes with lighter and darker spots, and pale below, sometimes with darker marginal bands and blotches.
The common stingaree is a species of stingray in the family Urolophidae. The most abundant ray in inshore waters off eastern Australia, it generally inhabits estuaries, sandy flats, and rocky reefs from the shore to a depth of 60 m (200 ft). This plain brownish to grayish species has a rounded pectoral fin disc with a broadly triangular snout. Its nostrils have enlarged lobes on their outer margins and a skirt-shaped curtain of skin with a fringed posterior margin between them. Its tail bears a small dorsal fin before the stinging spine, and terminates in a leaf-shaped caudal fin. This ray can grow to 52 cm (20 in) long.
The lobed stingaree is a common species of stingray in the family Urolophidae, endemic to southern Western Australia in shallow, inshore sand and seagrass habitats. This species is plain sandy in colour above and has a broad, rounded pectoral fin disc. It is characterized by an enlarged, semicircular skin lobe of unknown function on the inner rim of each nostril. Its tail is slender, with lateral skin folds and a lance-like caudal fin but no dorsal fin. The maximum recorded width is 27 cm (11 in).
The Australian grey smooth-hound or also known as the grey gummy shark is a species of houndshark classified under the large family Triakidae. It is one of the twenty-eight species belonging to the genus Mustelus, which are often small in length. While members of the genus Mustelus may be found globally in tropical and temperate waters, the grey gummy shark in particular is native to the Pacific Ocean and Indian Ocean waters surrounding Australia and is particularly widespread in deep coastal waters. The grey gummy shark is known to be a viviparous species and gives birth to live young. With little data available, it is regarded to have a relatively stable population and possesses little threat to humans.