Starspotted smooth-hound

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Starspotted smooth-hound
Manazo.png
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Carcharhiniformes
Family: Triakidae
Genus: Mustelus
Species:
M. manazo
Binomial name
Mustelus manazo
Bleeker, 1854
Mustelus manazo distmap.png

The starspotted smooth-hound (Mustelus manazo) is a houndshark of the family Triakidae. It is a medium-sized shark with irregular white spots across its body. It is found in Northwestern Pacific as well as Kenyan water. This shark mainly inhabits shallow seas and feeds on benthic animals. This shark is ovoviviparous and gives birth to 2-6 larvae per clutch. Currently, due to overfishing, this species is on the edge of extinction.

Contents

Description

Compared with other sharks, the star-spotted smooth-hound has a medium size. Sexually mature individuals typically have lengths between 62-72 cm. Largest known male has a total length of 96 cm while the largest female has a length of 118 cm. [2] Its body is elongated with a long tail and a flat head [3] .Its dorsal side is gray or grayish brown, with irregular white spots scattered near their lateral lines, and its abdomen is white. [2] Its eyes are oval with deep concavities outside. Its nostrils is wide with triangular nasal valves. The star-spotted smooth-hound has a triangular mouth with a large amount of small and interconnected teeth. Its teeth are oval or rhombus, overall blunt, unlike those possessed by other predatory sharks. Its first pair of dorsal fins are slightly larger than the second pair, starting at the end of the pectoral fins. The frontmost end of the anal fins is roughly at the midpoint of the second pair of dorsal fins. [3]

Distribution

The star-spotted smooth-hound is mainly found around the coastal waters of the northwest Pacific Ocean, ranging from southern Russia in the north to Brunei in the south, but some are also found in the coastal waters of Kenya in Africa. [1] [3] In addition, there are unconfirmed sightings of star-spotted smooth-hound recorded in the Andaman Sea and in the coastal waters of Madagascar and Bangladesh. [1]

Habitats

The star-spotted smooth-hound mainly inhabits continental shelves of temperate waters, especially waters with sandy or muddy substrates. They may occasionally enter estuaries to feed. [2] [3]

Diet

The star-spotted smooth-hound mainly feeds on benthic organisms. Most of its prey are crustaceans such as mantis shrimps, crabs, and shrimps. They also occasionally prey on annelids, brittle stars, cephalopods, shellfish, and small fishes. [4] [5] Some studies have pointed out that the stomach content weight of star-spotted smooth-hound in Tokyo Bay waters has a downward trend, which may be due to the decline in the benthic invertebrate populations on which they feed on. [5]

Life cycle

The star-spotted smooth-hound is ovoviviparous and usually mates between May and August, [6] giving birth to 2 to 6 young sharks in one litter, with a gestation period of about 10 months. [3] Newly born sharks are about 30 cm long. [2] Its age of star-spotted sexual maturity varies by location. For example, male sharks in waters around Taiwan can breed at the age of 1, while 6-year-old male sharks in the Aomori Bay may still be immature. Generally speaking, the female matures later than the male. Its length at sexual maturity also varies greatly depending on the sea area: star-spotted smooth-hound found near Taiwan is sexually mature around 30cm long, while individuals in Kanmon Strait and Maizuru Bay are generally mature at 60 to 70 cm in length. The star-spotted smooth-hound in Aomori Bay may still be immature until it is 90 cm long. [6] The maximum lifespan of this shark is about 17 years. [1]

Economic use

The fins of star-spotted smooth-hound can be used to make shark fin soup, while the remaining part is also edible. There are few specialized fishing activities for this shark, it is generally obtained as bycatch. [5] However, its meat and liver of star-spotted smooth-hounds are rich in mercury, which is harmful to human bodies, and the concentration of mercury is often higher than 1 ppm. [7]

Population conservation

Currently, the population status of star-spotted smooth-hound is in crisis. It is seriously affected by overfishing from China, Philippines, Vietnam, Malaysia, and Kenya, where these countries have large demands for seafood and have extremely large scales of fishing activities. Although some countries have policies such as restrictions on fishing activities at certain times of the year, there is no special conservation measurement for this species. In addition, frequent landfill activities in the Bohai Sea, Yellow Sea, East China Sea and other water have also seriously damaged the shallow sea habitats on which star-spotted smooth-hound relies on. [8] The above factors have caused a serious decline in the population of star-spotted smooth-hound. The IUCN 2020 report estimated that the population of star-spotted smooth-hound has declined by 50% to 79% in the past 33 years, and it is therefore rated as Endangered. [1]



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<span class="mw-page-title-main">Smooth-hound</span> Genus of sharks

Mustelus, also known as the smooth-hounds, is a genus of sharks in the family Triakidae. The name of the genus comes from the Latin word mustela, meaning weasel. It should not be confused with the genus name Mustela, which is used for weasels.

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The mandarin dogfish is a dogfish, a member of the family Squalidae in the order Squaliformes. It is found at depths of 140–650 metres (460–2,130 ft) off southern Japan, Taiwan, and Indonesia. Populations off Australia and New Zealand were formerly included in this species, but in 2007 these were assigned to a new species, the southern mandarin dogfish. It is not clear which of these species is involved in other populations from the tropical West Pacific.

The common smooth-hound is a houndshark of the family Triakidae. It is found in the eastern Atlantic Ocean from the British Isles to South Africa, and in the Mediterranean Sea, Madeira, and the Canary Islands at depths ranging from 5 to 625 m. While they can grow to 200 cm, their usual maximum size is 150 cm. They commonly grow to 100–120 cm with a birth length around 35 cm. The reproduction of commons smooth-hounds is viviparous.

<span class="mw-page-title-main">Japanese roughshark</span> Species of shark

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<span class="mw-page-title-main">Spotted houndshark</span> Species of shark

The spotted houndshark 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.

<span class="mw-page-title-main">Sharptooth houndshark</span> Species of shark

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.

<span class="mw-page-title-main">Banded houndshark</span> Species of shark

The banded houndshark 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.

<span class="mw-page-title-main">Smooth lanternshark</span> Species of shark

The smooth lanternshark or slender lanternshark is a species of dogfish shark in the family Etmopteridae, found widely in the Atlantic and Pacific Oceans. It inhabits benthic environments at a depth of 274–1,000 m (899–3,281 ft), and pelagic environments at a depth of 0–708 m (0–2,323 ft). The smooth lanternshark forms a species group with the larger blurred lanternshark, both of which are distinguished from other members of their family by small, irregularly arranged dermal denticles with a truncated shape. This species has a slender, dark brown body with an indistinct black band on the sides over the pelvic fins, and reaches 50 cm (20 in) in length. This slow-growing, ovoviviparous shark feeds on smaller squid, fishes, and fish eggs. Smooth lanternsharks are often caught as bycatch in eastern Atlantic and Japanese commercial fisheries. The International Union for Conservation of Nature (IUCN) has evaluated this species as of Least Concern because of its wide distribution and limited threats.

<span class="mw-page-title-main">Starry smooth-hound</span> Species of shark

The starry smooth-hound is a houndshark of the family Triakidae. It is found on the continental shelves of the northeast Atlantic, between latitudes 61 and 16° N, from the surface to a depth of 200 m (660 ft).

<span class="mw-page-title-main">Gray smooth-hound</span> Species of shark

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<span class="mw-page-title-main">Spotless smooth-hound</span> Species of shark

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<span class="mw-page-title-main">Brown smooth-hound</span> Species of shark

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<span class="mw-page-title-main">Small-spotted catshark</span> Species of shark

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<span class="mw-page-title-main">Australian grey smooth-hound</span> Species of shark

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.

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