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Diagnostic Description ( англиски )

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A small species which is distinguished by the following characters: snout moderately long and bluntly pointed; upper anterior teeth oblique and blade-like, coarsely serrated laterally, lateral margin deeply notched and with several large and smooth basal cusplets; lower anterior teeth narrower, slightly oblique, lateral margins usually not notched and with several large basal serrae, mostly smooth; total tooth row 24-28/22-27 or 47-55; interdorsal space often without a ridge on midline, 19.0-22.4% TL; first dorsal fin is moderately tall and falcate, origin about opposite pectoral-fin free rear tip, length 14.7-16.0% TL, 1.3-1.7 times height, inner margin 2.1-2.7 in base; second dorsal fin is much smaller, broadly triangular, height 31-37% of first dorsal fin height, its origin slightly posterior to anal-fin origin; anal fin falcate, height 0.9-1.2 times second dorsal height, base 1.0-1.3 times second dorsal-fin base; body colour pale brownish to grey dorsally, whitish ventrally; second dorsal fin with a black blotch covering most of fin and often extending slightly onto upper surface of body, usually diffuse-edged and poorly defined from ground colour of fin; other fins are plain or with pale outer margins; total vertebral 146-163; monospondylous precaudal 42-48; diplospondylous precaudal 26-38; diplospondylous caudal 74-81; precaudal 71-82 (Ref. 89954).
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Estelita Emily Capuli
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Life Cycle ( англиски )

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Viviparous, with a yok-sac placenta; 1-2 pups per litter (Ref. 244); after a gestation period of ~ 9 months(Ref.58048). 33-45 cm TL at birth (Ref. 9997). Distinct pairing with embrace (Ref. 205).
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Cristina V. Garilao
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Trophic Strategy ( англиски )

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Feeds on fish, squids and shrimps (Ref. 5578).
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Pascualita Sa-a
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Biology ( англиски )

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Found on the continental and insular shelves, from the surf line and intertidal region to deeper water (Ref. 244). Feeds on small bony fishes (including sea horses), prawns, and squid (Ref. 9997). Viviparous (Ref. 50449). Specimens caught with size ranging from 37.0-67.4 cm TL were found to be immature, males apparently begin to mature around 71.0 cm TL and birth size is between 32.0 and 37.0 cm TL (Ref. 89954). Often caught by shore anglers (Ref. 5485). Utilized as a food fish (Ref. 244).
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Kent E. Carpenter
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Importance ( англиски )

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fisheries: commercial; gamefish: yes
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Blackspot shark ( англиски )

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The blackspot shark (Carcharhinus sealei) is a small species of requiem shark in the family Carcharhinidae found in the tropical Indo-West Pacific Ocean between latitudes 24°N and 30°S, from the surface to a depth around 40 m (130 ft). Its length is a little under one meter (yard) and it is not considered to be dangerous to humans. It feeds mainly on fish, crustaceans, and squid. This shark is also caught in small-scale fisheries for human consumption.

Description

The blackspot shark is a relatively slender species with a streamlined appearance, growing to a length around 95 cm (37 in). The snout is fairly long, pointed or slightly rounded at the tip. The eyes are large, oval, and set horizontally, and are protected by a nictitating membrane on the lower side. The flaps of skin beside the nostrils are triangular, and the furrows on the upper lip are short. Usually, 12 tooth rows occur on either side of both top and bottom jaws, but the number can vary from 11 to 13. The upper teeth have strongly serrated oblique cusps and smooth-edged cusplets, and the lower teeth have oblique cusps, either serrated or smooth. The hindermost of the five gill slits is above the origin of the pectoral fins, and no spiracles occur. The first dorsal fin is long, narrow, and curved (falcate) and has a short rear tip. It is either pointed or narrowly rounded at the apex and its origin is directly over the free posterior end of the pectoral fins. The second dorsal fin is relatively large. It also has a short rear tip and its origin is slightly behind the origin of the anal fin. The pectoral fins are falcate, long and narrow, and taper to a blunt point. No fleshy keel exists along the sides of the caudal peduncle. The caudal fin is about one-fifth of the total length of the shark, the dorsal lobe is elongated and has a notch in the lower margin near the tip and the ventral lobe is smaller, markedly falcate, and has a more rounded tip. The body colour is brownish or silvery grey on the dorsal surface and pale grey on the ventral surface, with an inconspicuous pale stripe running along the flank. A large, triangular black spot is on the second dorsal fin which covers at least half of the fin. The other fins have no distinctive markings, but do have pale posterior edges.[3][4]

The blackspot shark can be confused with the whitecheek shark (Carcharhinus dussumieri),[5] but that species has a triangular first dorsal fin that is only slightly falcate, and a small second dorsal fin that merely has a dark margin.[6]

Distribution

The blackspot shark is native to the Indian and Pacific Oceans, where it is found on the continental shelves and shallow water around islands from the surf line to depths of about 40 m (130 ft). It is not usually found in estuaries and may be intolerant of low-salinity water. In the Indian Ocean, it is found along the east coast of Africa from South Africa and Madagascar to Kenya. It is present in the water around the Seychelles and Mauritius, and further east, it is present around the coasts of Pakistan, India, and Sri Lanka. In the western Pacific Ocean, it is found along the coasts of Thailand, Vietnam, China, Indonesia, New Guinea, and northern and western Australia.[3] In South Africa, the species seems to be resident, but some increase in numbers occurs during the summer.[3]

Biology

The blackspot shark feeds on small fish, crustaceans, and squid, and is not dangerous to man.[3] It is a fast-growing, short-lived species. It is mature at about one year old at a length around 70 cm (28 in) and can live for five years or more. Like other members of its genus, the blackspot shark is viviparous. The gestation period is about 9 months and one or two offspring develop at one time in the uterus. At first, the embryos are sustained by a yolk sac, but later a placenta develops. Off the coast of Natal, the juvenile sharks are born in spring.[7]

Status

The blackspot shark is listed as vulnerable by the IUCN in its Red List of Threatened Species. Detailed surveys of population size have not been done, but the population is believed to be in decline. The shallow waters in which the fish live are intensively fished with longlines and gillnets, and the blackspot shark may be overexploited through overfishing. It is sold in local markets and its flesh is used for human consumption.[1]

References

  1. ^ a b Dulvy, N.K., Bin Ali, A., Bineesh, K.K., Derrick, D., Seyha, L., Tanay, D., VanderWright, W.J., Vo, V.Q., Yuneni, R.R., Maung, A. & Utzurrum, J.A.T. (2021). "Carcharhinus sealei". IUCN Red List of Threatened Species. 2021. Retrieved 21 October 2021.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  2. ^ a b Bailly, Nicolas (2013). "Carcharhinus sealei (Pietschmann, 1913)". WoRMS. World Register of Marine Species. Retrieved 2013-06-18.
  3. ^ a b c d "Blackspot shark (Carcharhinus sealei)". Sharks of the World. Marine Species Identification Portal. Retrieved 2013-06-18.
  4. ^ "Carcharhinidae: Requiem sharks". Encyclopedia of Life. Retrieved 2013-06-18.
  5. ^ Carpenter, Kent E. "Carcharhinus sealei (Pietschmann, 1913)". FishBase. Retrieved 2013-06-18.
  6. ^ "Whitecheek shark (Carcharhinus dussumieri)". Sharks of the World. Marine Species Identification Portal. Archived from the original on 2016-03-03. Retrieved 2013-06-18.
  7. ^ Van Der Elst, Rudy (1993). A Guide to the Common Sea Fishes of Southern Africa. Struik. p. 367. ISBN 9781868253944.
Wikimedia Commons has media related to Carcharhinus sealei.
Wikispecies has information related to Blackspot shark.
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Blackspot shark: Brief Summary ( англиски )

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The blackspot shark (Carcharhinus sealei) is a small species of requiem shark in the family Carcharhinidae found in the tropical Indo-West Pacific Ocean between latitudes 24°N and 30°S, from the surface to a depth around 40 m (130 ft). Its length is a little under one meter (yard) and it is not considered to be dangerous to humans. It feeds mainly on fish, crustaceans, and squid. This shark is also caught in small-scale fisheries for human consumption.

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Description ( англиски )

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Found on the continental and insular shelves, from the surf line and intertidal region to deeper water. Feeds on small fish including sea horses, shrimps, and squids. Viviparous; 1-2 pups per litter; 35-45 cm at birth (Ref. 2334). Often caught by shore anglers (Ref. 5485). Utilized for human consumption.

Навод

Froese, R. & D. Pauly (Editors). (2023). FishBase. World Wide Web electronic publication. version (02/2023).

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