Broadfin shark

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Broadfin shark
Carcharias temminckii by muller and henle.png
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Order: Carcharhiniformes
Family: Carcharhinidae
Genus: Lamiopsis
Species:
L. temminckii
Binomial name
Lamiopsis temminckii
Lamiopsis temmincki distmap.png
Range of the broadfin shark
Synonyms

Carcharhinus microphthalmus
Carcharhinus temmincki
Carcharias temminckii
Carcharinus temminckii
Carcharias (Prionodon) temminckii
Carcharinus temminckii
Eulamia temmincki
Eulamia temminckii
Lamiopsis temmincki
Squalus (Carcharinus) temminckii

Contents

The broadfin shark (Lamiopsis temminckii) is a tropical whaler shark, characterized by the broad shape of its pectoral fins. [1] They are classified as requiem sharks of the family Carcharhinidae. This is one of two species in the genus Lamiopsis, the other being the Borneo broadfin shark (Lamiopsis tephrodes). [2] The broadfin shark is native to the northern Indian Ocean, and is found close to shore. Its current status according to the IUCN is endangered. [3]

Description

Females and males of the broadfin shark species are sexually dimorphic. Females, on average, are larger than males, and it is reported that males mature at a smaller size than females. The reported size of females has decreased when compared with previous recordings of the species, with the new maximum size of females being around 175 cm (69 in), while the reported size of males has increased. Another way to tell males and females apart is by looking at the end of their pelvic fins, as males possess calcified claspers (external appendage that aid in reproduction) on the ends of their pelvic fins. [4]

Distribution and habitat

The broadfin shark is found in both the Indian Ocean and the Pacific Ocean. Its distribution is sporadic, with sightings occurring off the coasts of Pakistan, India, Indonesia, Burma, China, and Sarawak. The species tends to spend most of its time in coastal waters, not far off the coast and within the continental shelf. Females and males are evenly distributed throughout their habitat range. [4]

Biology

Reproduction

Lamiopsis temminckii is a placental viviparous species. This means that young have an umbilical scar left over at birth. Females of this species average two to four embryos per uterus at a time, and the typical amount of embryos total in a litter averages to be around eight at a time. Late term embryos are common in the summer (April–August), and births are estimated to occur most often during the pre southwest monsoon season and southwest monsoon season from March to September. At birth, the broadfin shark ranges in size from 41.8–65.0 cm (16.5–25.6 in). The shark has a low productivity rate, and therefore, a limited rebound potential. [4]

Feeding

The broadfin shark primarily feeds on crustaceans, teleosts, and cephalopods. Analysis of the stomach contents of 214 individuals revealed that crustaceans are their most abundant prey. [4] The broadfin shark is a top predator in its coastal habitats; however, it has been documented that the shark is parasitized by Sanguilevator yearsleyi, a blood sequestering tapeworm. [5]

Anthropogenic influences and conservation

The broadfin shark is known to be endangered globally. However, this may need to be reassessed as it was last assessed before the identification of the Borneo broadfin shark (Lamiopsis tephrodes). It is likely that misidentifying Borneo broadfin sharks as broadfin sharks could have skewed the population numbers. Therefore, it is possible that the actual status of the broadfin shark population has been recorded as healthier than it truly is, and they may belong in the critically endangered list. This is still to be determined. [1]

While, there have always low population numbers, at one time the species was considered to be common in heavily fished areas like Indonesia, the Arabian Sea, and the western coast of India. [1] This is thought to be part of the reason that the shark's population is now on the decline, as one main reason for its endangerment status is that it is often by-catch in sailors’ nets. Juveniles are unproportionately caught in the late summer months, as their birthing season lines up with the seasonal closure of mechanized fishing throughout their habitat. This issue is especially common within the Arabian Sea and along the coast of India. Since the shark frequents inshore areas, especially those that have an abundance of fish, they are at risk of getting caught in bottom nets, floating gill nets, and fishing line. Little effort has been made to remediate this issue. [4] Another reason for the declining population of the broadfin shark is the culture surrounding shark fin soup, which is thought to be a delicacy in many Asian countries. Sharks are also fished for their meat and their liver, which is used for vitamin oil. [1] However new policies are being developed to prevent this from happening further.

Related Research Articles

<span class="mw-page-title-main">Requiem shark</span> Family of sharks

Requiem sharks are sharks of the family Carcharhinidae in the order Carcharhiniformes. They are migratory, live-bearing sharks of warm seas and include such species as the tiger shark, bull shark, lemon shark, spinner shark, blacknose shark, blacktip shark, grey reef shark, blacktip reef shark, silky shark, dusky shark, blue shark, copper shark, oceanic whitetip shark, and whitetip reef shark.

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

The winghead shark is a species of hammerhead shark, and part of the family Sphyrnidae. Reaching a length of 1.9 m (6.2 ft), this small brown to gray shark has a slender body with a tall, sickle-shaped first dorsal fin. Its name comes from its exceptionally large "hammer", or cephalofoil, which can be as wide as half of the shark's total length. The function of this structure is unclear, but may relate to the shark's senses. The wide spacing of its eyes grants superb binocular vision, while the extremely long nostrils on the leading margin of the cephalofoil may allow for better detection and tracking of odor trails in the water. The cephalofoil also provides a large surface area for its ampullae of Lorenzini and lateral line, with potential benefits for electroreception and mechanoreception, respectively.

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

The dusky shark is a species of requiem shark, in the family Carcharhinidae, occurring in tropical and warm-temperate continental seas worldwide. A generalist apex predator, the dusky shark can be found from the coast to the outer continental shelf and adjacent pelagic waters, and has been recorded from a depth of 400 m (1,300 ft). Populations migrate seasonally towards the poles in the summer and towards the equator in the winter, traveling hundreds to thousands of kilometers. One of the largest members of its genus, the dusky shark reaches 4.2 m (14 ft) in length and 347 kg (765 lb) in weight. It has a slender, streamlined body and can be identified by its short round snout, long sickle-shaped pectoral fins, ridge between the first and second dorsal fins, and faintly marked fins.

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

The spadenose shark is a species of requiem shark in the family Carcharhinidae. It is common in the tropical Indian and western Pacific Oceans, where it forms large schools in shallow water. A small shark reaching a length of 74 cm (29 in), the spadenose shark is named for its distinctively flattened, triangular snout. It is a predator of small bony fishes and invertebrates. This species exhibits the most advanced mode of viviparity of any fish, in which the developed embryos form a highly complex placental connection to the mother at a very small size. Females breed year-round, giving birth to six to 18 pups after a gestation period of 5–6 months. The spadenose shark is harmless to humans and is valued by artisanal and commercial fishers for its meat and fins. Its abundance ensures it forms a significant component of many fisheries in South and Southeast Asia. The International Union for Conservation of Nature has assessed this species as Near threatened. This fish is also known as mori in Goa

Scoliodon is a genus of requiem sharks in the family Carcharhinidae. It was formerly thought to include only a single Indo-Pacific species, the spadenose shark, but recent taxonomic research has found an additional species, the Pacific spadenose shark.

<i>Lamiopsis</i> Genus of sharks

Lamiopsis is a genus of shark in the family Carcharhinidae found in Indian and Pacific Ocean. This genus was previously considered to be monotypic. However, a recent taxonomic study revealed that the western central Pacific populations were a separate species.

<span class="mw-page-title-main">Sicklefin lemon shark</span> Species of shark

The sicklefin lemon shark or sharptooth lemon shark is a species of requiem shark belonging to the family Carcharhinidae, widely distributed in the tropical waters of the Indo-Pacific. It is closely related to the better-known lemon shark of the Americas; the two species are almost identical in appearance, both being stout-bodied sharks with broad heads, two dorsal fins of nearly equal size, and a plain yellow-tinged coloration. As its common name suggests, the sicklefin lemon shark differs from its American counterpart in having more falcate (sickle-shaped) fins. This large species grows up to 3.8 m (12 ft) long. It generally inhabits water less than 92 m (302 ft) deep in a variety of habitats, from mangrove estuaries to coral reefs.

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

The speartooth shark is a rare species of river shark, belonging to the family Carcharhinidae. It inhabits coastal marine waters and tidal reaches of large tropical rivers in northern Australia and New Guinea. Despite being a member of the river shark genus, it is also found in near-shore marine waters, favoring highly turbid environments over a wide range of salinities. This robustly built, gray-colored shark is characterized by a short and broad snout, tiny eyes, a relatively large second dorsal fin, and a black blotch beneath each pectoral fin near the tip. Another identifying trait is its teeth, which are large, triangular, and serrated in the upper jaw and narrow, spear-like, and serrated only near the tips in the lower jaw. Adults grow to about 2.6 m (8.5 ft) long.

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

The blacknose shark is a species of requiem shark, belonging to the family Carcharhinidae, common in the tropical and subtropical waters of the western Atlantic Ocean. This species generally inhabits coastal seagrass, sand, or rubble habitats, with adults preferring deeper water than juveniles. A small shark typically measuring 1.3 m (4.3 ft) long, the blacknose has a typical streamlined "requiem shark" shape with a long, rounded snout, large eyes, and a small first dorsal fin. Its common name comes from a characteristic black blotch on the tip of its snout, though this may be indistinct in older individuals.

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

The graceful shark or Queensland shark is a species of requiem shark, in the family Carcharhinidae, found in the tropical Indo-Pacific, from the Gulf of Aden to northern Australia. It is a midwater species that has been recorded to a depth of 50 m (160 ft). A stoutly built shark growing up to 1.7 m (5.6 ft) long, the graceful shark has a short, wedge-shaped snout, large, sickle-shaped pectoral fins and first dorsal fin, and black tips on most fins.

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

The hardnose shark is a species of requiem shark, in the family Carcharhinidae, so named because of the heavily calcified cartilages in its snout. A small bronze-coloured shark reaching a length of 1.1 m (3.6 ft), it has a slender body and a long, pointed snout. Its two modestly sized dorsal fins have distinctively elongated rear tips. The hardnose shark is widely distributed in the western Indo-Pacific, from Kenya to southern China and northern Australia. It inhabits warm, shallow waters close to shore.

<span class="mw-page-title-main">Creek whaler</span> Species of shark

The creek whaler is a common species of requiem shark, and part of the family Carcharhinidae, endemic to northern Australia. It frequents shallow waters close to shore, including estuaries. This small, stocky shark usually grows to 1.0–1.3 m (3.3–4.3 ft) long and is brownish in color without conspicuous fin markings. It can be identified by its long snout, large, triangular pectoral fins, and large, anteriorly positioned first dorsal fin.

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

The pigeye shark or Java shark is an uncommon species of requiem shark, in the family Carcharhinidae, found in the warm coastal waters of the eastern Atlantic and western Indo-Pacific. It prefers shallow, murky environments with soft bottoms, and tends to roam within a fairly localised area. With its bulky grey body, small eyes, and short, blunt snout, the pigeye shark looks almost identical to the better-known bull shark. The two species differ in vertebral count, the relative sizes of the dorsal fins, and other subtle traits. This shark typically reaches lengths of 1.9–2.5 m (6.2–8.2 ft).

<span class="mw-page-title-main">Borneo shark</span> Rare species of requiem shark

The Borneo shark is a species of requiem shark, and part of the family Carcharhinidae. Extremely rare, it is known only from inshore waters around Mukah in northwestern Borneo, though it may once have been more widely distributed. A small, gray shark reaching 65 cm (26 in) in length, this species is the only member of its genus with a row of enlarged pores above the corners of its mouth. It has a slender body with a long, pointed snout and a low second dorsal fin placed posterior to the anal fin origin.

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

The Pondicherry shark is an extremely rare species of requiem shark, in the family Carcharhinidae. A small and stocky gray shark, it grows not much longer than 1 m (3.3 ft) and has a fairly long, pointed snout. This species can be identified by the shape of its upper teeth, which are strongly serrated near the base and smooth-edged near the tip, and by its first dorsal fin, which is large with a long free rear tip. Furthermore, this shark has prominent black tips on its pectoral fins, second dorsal fin, and caudal fin lower lobe.

<span class="mw-page-title-main">Smoothtooth blacktip shark</span> Species of shark

The smoothtooth blacktip shark is a species of requiem shark in the family Carcharhinidae. It is known only from the type specimen caught from the Gulf of Aden, off eastern Yemen, and a handful of additional specimens caught from the Persian Gulf, off Kuwait. Reaching 1.3 m (4.3 ft) in length, this species has a stocky greenish-colored body, a short snout, and black-tipped fins. It can be distinguished from similar species by its teeth, which are narrow, erect, and smooth-edged.

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

The milk shark is a species of requiem shark, and part of the family Carcharhinidae, whose common name comes from an Indian belief that consumption of its meat promotes lactation. The largest and most widely distributed member of its genus, the milk shark typically measures 1.1 m (3.6 ft) long, and can be found in coastal tropical waters throughout the eastern Atlantic and the Indo-Pacific regions. Occurring from the surface to a depth of 200 m (660 ft), this species is common near beaches and in estuaries, and has been recorded swimming up rivers in Cambodia. Juveniles are known to inhabit tidal pools and seagrass meadows. The milk shark has a slender body with a long, pointed snout and large eyes, and is a nondescript gray above and white below. This shark can be distinguished from similar species in its range by the long furrows at the corners of its mouth, and seven to 15 enlarged pores just above them.

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

The barbeled houndshark is a species of ground shark and the only member of the family Leptochariidae. This demersal species is found in the coastal waters of the eastern Atlantic Ocean from Mauritania to Angola, at depths of 10–75 m (33–246 ft). It favors muddy habitats, particularly around river mouths. The barbeled houndshark is characterized by a very slender body, nasal barbels, long furrows at the corners of the mouth, and sexually dimorphic teeth. Its maximum known length is 82 cm (32 in).

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

The Australian weasel shark is an uncommon species of ground shark in the family Hemigaleidae. It inhabits shallow waters off northern Australia to a depth of 170 m (560 ft); smaller sharks frequent sand and seagrass habitat and shift to coral reefs as they grow older. A slim, drab species reaching a length of 1.1 m (3.6 ft), it has sickle-shaped fins with dark tips on the second dorsal fin and caudal fin upper lobe. Its upper teeth are broad with strong serrations only on the trailing edge. The lateral line along each side is prominent and exhibits a downward curve below the second dorsal fin.

<i>Carcharhinus tjutjot</i> Species of shark

The Indonesian whaler shark, is a species of requiem shark belonging to the family Carcharhinidae. Until recently, it was thought to be a junior synonym of the whitecheek shark. The Indonesian whaler shark, along with the family Carcharhinidae, is a key economic group in global fisheries including commercial and small-scale fisheries within the Indo-Pacific region. Common spawning and nursery areas overlap with commercial fishing grounds and it is often caught as bycatch which has caused it to be listed as a vulnerable species.

References

  1. 1 2 3 4 White, William T.; Last, Peter R.; Naylor, Gavin J.P.; Harris, Mark (2010). "Resurrection and redescription of the Borneo Broadfin Shark Lamiopsis tephrodes (Fowler, 1905) (Carcharhiniformes: Carcharhinidae)". CSIRO Marine and Atmospheric Research Paper. 32 (165): 45–59.
  2. Akhilesh, K.V.; White, W.T.; Bineesh, K.K.; Purushottama, G.B.; Singh, V.V.; Singh, V.V.; Zacharia, P.U. (2016-10-12). "Redescription of the rare and endangered Broadfin Shark Lamiopsis temminckii (Müller & Henle, 1839) (Carcharhiniformes:Carcharhinidae) from the northeastern Arabian Sea". Zootaxa. 4175 (2): 155–166. doi:10.11646/zootaxa.4175.2.3. ISSN   1175-5334. PMID   27811779.
  3. Pal, Mousumi; Kar, Subrata; Mishra, Subhrendu S. (2014). "An overview of the fishes of Indian Sundarbans and their conservation status". Journal of Environment and Sociobiology. 11 (2): 171–185. ISSN   0973-0834 via Research Gate.
  4. 1 2 3 4 5 Akhilesh, K. V.; Purushottama, G. B.; Thakurdas; Kizhakudan, S. J. (2017-10-16). "Biological observations on the broadfin shark Lamiopsis temminckii (Carcharhiniformes: Carcharhinidae)". Journal of Fish Biology. 91 (6): 1721–1729. doi:10.1111/jfb.13474. ISSN   0022-1112. PMID   29034466.
  5. Caira, J. N.; Mega, J.; Ruhnke, T. R. (2005). "An unusual blood sequestering tapeworm (Sanguilevator yearsleyi n. gen., n. sp.) from Borneo with description of Cathetocephalus resendezi n. sp. from Mexico and molecular support for the recognition of the order Cathetocephalidea (Platyhelminthes: Eucestoda)*" (PDF). International Journal for Parasitology. 35 (10): 1135–1152. doi:10.1016/j.ijpara.2005.03.014. PMID   16019004 via University of Connecticut.