Arabian carpetshark
Encyclopedia
The Arabian carpetshark (Chiloscyllium arabicum) is a species
of carpet shark
in the family
Hemiscylliidae
, inhabiting coral reef
s and other shallow coastal habitat
s from the Persian Gulf
to India
. Reaching 78 cm (30.7 in) long, this shark is characterized by a slender, plain brown body, and by two dorsal fin
s with straight trailing margins and the second smaller but longer-based than the first. The Arabian carpetshark feeds on bony fishes and invertebrate
s. Reproduction is oviparous with an annual cycle; females deposit egg capsules four at a time and the young hatch after 70–80 days. This small shark is often captured as bycatch
but rarely used by humans. It has been assessed as Near Threatened
by the International Union for Conservation of Nature (IUCN), as there is increasing fishing pressure and habitat degradation within its range. It does well in aquariums
and has been bred in captivity.
(C. griseum); it is uncertain whether the ranges of these two similar sharks in fact overlap. No type specimens are known. Other common name
s for this species include Arabian bamboo shark and confusing bamboo shark.
to Pakistan
and western India
; it is abundant in the Persian Gulf in spring and summer, and seldom reported from Oman
and India. This demersal species favors coral reef
s, lagoon
s, rocky coastlines, and mangrove
estuaries.
s are set a good distance from the snout tip and preceded by a pair of short barbels. The eyes are medium-sized and placed high on the head, each with a low ridge above and a large spiracle
behind and below. The small mouth lies well forward of the eyes; there is a continuous fold of skin across the chin that wraps around the corners of the mouth. There are 26–35 upper tooth rows and 21–32 lower tooth rows. The teeth have a large central cusp and a pair of lateral cusplets. The five pairs of gill slit
s are short, with the fourth and fifth pairs very close together.
The pectoral fins are small, broad, and rounded; the pelvic fins are similar and almost as large. The two dorsal fin
s have straight trailing margins and are spaced well apart. The first dorsal fin is as large or larger than the pelvic fins, originating behind the middle of the pelvic fin bases. The second dorsal fin is slightly smaller than the first but has a longer base. There is a prominent midline ridge along the back, which continues between the dorsal fins. The long, keel-like anal fin originates behind the second dorsal fin. The caudal fin is low and lacks a lower lobe; the upper lobe has a strong ventral notch near the tip. Adults are a plain tan color above and white below, sometimes with an orange tint on the fin margins; juveniles have faint lighter spots on the fins. This species reaches a maximum known length of 78 cm (30.7 in).
s (including stomatopods, shrimp
, crab
s, squid
, gastropods, and echiuroid worms
). This hardy species can survive for some time out of water. It is oviparous like other members of its family, with a six-month breeding season. The reproductive cycle has been documented in captivity: copulation involves the male holding onto one of the female's pectoral fins with his mouth, while inserting a single clasper into her cloaca
for 5–15 minutes. When competing for mates, male sharks have been known to bite the claspers of rival males. Females produce an average of 33 egg capsules per year in batches of four, that are laid over a period of 20 minutes to two days. Of those eggs, about 7% are infertile. The egg cases have adhesive tendrils for securing them to coral, and hatch in 70–80 days at a temperature of 24 °C (75.2 °F). Newly emerged young measure under 10 cm (3.9 in) long; sexual maturity
is attained at a length of 45–54 cm (17.7–21.3 in).
. It is collected for the aquarium trade, which is not believed to pose a substantial threat to its population. The meat and possibly the fins of this shark can be used, but because of its size most individuals landed are discarded. It is captured incidentally
in intertidal
hadra (artisanal
stake-net traps
), as well as in demersal trammel and trawl nets. The Arabian carpetshark forms the predominant component of the "cat shark" catch of Kuwait
i prawn
trawls, which represents the second-largest bycatch (14% of total) of the fishery
. It is also caught off Bahrain
and likely elsewhere. Another potentially major threat to this species is habitat degradation: coral reefs in the Persian Gulf face bottom trawling, coastal development (especially large-scale land reclamation
projects such as in the United Arab Emirates
), Turkish
dam
s on the Tigris
-Euphrates
river system, draining of marsh
es in Iraq
, and oil spill
s. Coastal habitats off India are also similarly pressured. As both fishing and habitat degradation are likely to intensify in the region, the International Union for Conservation of Nature (IUCN) has assessed the Arabian carpetshark as Near Threatened
.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of carpet shark
Carpet shark
The carpet sharks are an order, Orectolobiformes, of sharks, so called because many members have ornate patterns reminiscent of carpets....
in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Hemiscylliidae
Hemiscylliidae
Hemiscylliidae is a family of sharks in the order Orectolobiformes, commonly known as longtail carpet sharks or bamboo sharks. They are found in shallow waters of the tropical Indo-Pacific....
, inhabiting coral reef
Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
s and other shallow coastal habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s from the Persian Gulf
Persian Gulf
The Persian Gulf, in Southwest Asia, is an extension of the Indian Ocean located between Iran and the Arabian Peninsula.The Persian Gulf was the focus of the 1980–1988 Iran-Iraq War, in which each side attacked the other's oil tankers...
to India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
. Reaching 78 cm (30.7 in) long, this shark is characterized by a slender, plain brown body, and by two dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
s with straight trailing margins and the second smaller but longer-based than the first. The Arabian carpetshark feeds on bony fishes and invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s. Reproduction is oviparous with an annual cycle; females deposit egg capsules four at a time and the young hatch after 70–80 days. This small shark is often captured as bycatch
Bycatch
The term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...
but rarely used by humans. It has been assessed as Near Threatened
Near Threatened
Near Threatened is a conservation status assigned to species or lower taxa that may be considered threatened with extinction in the near future, although it does not currently qualify for the threatened status...
by the International Union for Conservation of Nature (IUCN), as there is increasing fishing pressure and habitat degradation within its range. It does well in aquariums
Fishkeeping
Fishkeeping is a popular hobby concerned with keeping fish in a home aquarium or garden pond. There is also a fishkeeping industry, as a branch of agriculture.-Types of fishkeeping systems:...
and has been bred in captivity.
Taxonomy
Prior to being described as a new species in Gubanov and Schleib's 1980 Sharks of the Arabian Gulf, the Arabian carpetshark was misreported as the grey bamboo sharkGrey bamboo shark
The grey bamboo shark, Chiloscyllium griseum, is a species of carpet shark in the family Hemiscylliidae, found in the Indo-West Pacific Oceans from the Arabian Sea to Pakistan, India, Malaysia, Thailand, Indonesia, China, Japan, the Philippines, and Papua New Guinea, between latitudes 34° N and 10°...
(C. griseum); it is uncertain whether the ranges of these two similar sharks in fact overlap. No type specimens are known. Other common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
s for this species include Arabian bamboo shark and confusing bamboo shark.
Distribution and habitat
The Arabian carpetshark inhabits coastal waters 3–100 m (9.8–328.1 ft) deep, though most are found shallower than 10 m (32.8 ft). Its range extends from the Persian GulfPersian Gulf
The Persian Gulf, in Southwest Asia, is an extension of the Indian Ocean located between Iran and the Arabian Peninsula.The Persian Gulf was the focus of the 1980–1988 Iran-Iraq War, in which each side attacked the other's oil tankers...
to Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...
and western India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
; it is abundant in the Persian Gulf in spring and summer, and seldom reported from Oman
Oman
Oman , officially called the Sultanate of Oman , is an Arab state in southwest Asia on the southeast coast of the Arabian Peninsula. It is bordered by the United Arab Emirates to the northwest, Saudi Arabia to the west, and Yemen to the southwest. The coast is formed by the Arabian Sea on the...
and India. This demersal species favors coral reef
Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
s, lagoon
Lagoon
A lagoon is a body of shallow sea water or brackish water separated from the sea by some form of barrier. The EU's habitat directive defines lagoons as "expanses of shallow coastal salt water, of varying salinity or water volume, wholly or partially separated from the sea by sand banks or shingle,...
s, rocky coastlines, and mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
estuaries.
Description
The Arabian carpetshark has a slender, nearly cylindrical body and a relatively long, thick, rounded snout. The nostrilNostril
A nostril is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation...
s are set a good distance from the snout tip and preceded by a pair of short barbels. The eyes are medium-sized and placed high on the head, each with a low ridge above and a large spiracle
Spiracle
Spiracles are openings on the surface of some animals that usually lead to respiratory systems.-Vertebrates:The spiracle is a small hole behind each eye that opens to the mouth in some fishes. In the primitive jawless fish the first gill opening immediately behind the mouth is essentially similar...
behind and below. The small mouth lies well forward of the eyes; there is a continuous fold of skin across the chin that wraps around the corners of the mouth. There are 26–35 upper tooth rows and 21–32 lower tooth rows. The teeth have a large central cusp and a pair of lateral cusplets. The five pairs of gill slit
Gill slit
Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of Cartilaginous fish such as sharks, rays, sawfish, and guitarfish. Most of these have five pairs, but a few species have 6 or 7 pairs...
s are short, with the fourth and fifth pairs very close together.
The pectoral fins are small, broad, and rounded; the pelvic fins are similar and almost as large. The two dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
s have straight trailing margins and are spaced well apart. The first dorsal fin is as large or larger than the pelvic fins, originating behind the middle of the pelvic fin bases. The second dorsal fin is slightly smaller than the first but has a longer base. There is a prominent midline ridge along the back, which continues between the dorsal fins. The long, keel-like anal fin originates behind the second dorsal fin. The caudal fin is low and lacks a lower lobe; the upper lobe has a strong ventral notch near the tip. Adults are a plain tan color above and white below, sometimes with an orange tint on the fin margins; juveniles have faint lighter spots on the fins. This species reaches a maximum known length of 78 cm (30.7 in).
Biology and ecology
Commonly found sheltering inside caves and crevices, the Arabian carpetshark is a predator of bony fishes (including snake eels) and invertebrateInvertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s (including stomatopods, shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
, crab
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s, squid
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
, gastropods, and echiuroid worms
Echiura
The Echiura, or spoon worms, are a small group of marine animals. They are often considered to be a group of annelids, although they lack the segmented structure found in other members of that group, and so may also be treated as a separate phylum...
). This hardy species can survive for some time out of water. It is oviparous like other members of its family, with a six-month breeding season. The reproductive cycle has been documented in captivity: copulation involves the male holding onto one of the female's pectoral fins with his mouth, while inserting a single clasper into her cloaca
Cloaca
In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, reproductive, and urinary tracts of certain animal species...
for 5–15 minutes. When competing for mates, male sharks have been known to bite the claspers of rival males. Females produce an average of 33 egg capsules per year in batches of four, that are laid over a period of 20 minutes to two days. Of those eggs, about 7% are infertile. The egg cases have adhesive tendrils for securing them to coral, and hatch in 70–80 days at a temperature of 24 °C (75.2 °F). Newly emerged young measure under 10 cm (3.9 in) long; sexual maturity
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
is attained at a length of 45–54 cm (17.7–21.3 in).
Human interactions
Small and harmless to humans, the Arabian carpetshark is one of the few shark species suitable for private aquariaFishkeeping
Fishkeeping is a popular hobby concerned with keeping fish in a home aquarium or garden pond. There is also a fishkeeping industry, as a branch of agriculture.-Types of fishkeeping systems:...
. It is collected for the aquarium trade, which is not believed to pose a substantial threat to its population. The meat and possibly the fins of this shark can be used, but because of its size most individuals landed are discarded. It is captured incidentally
Bycatch
The term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...
in intertidal
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...
hadra (artisanal
Artisan fishing
Artisan fishing is a term used to describe small scale low-technology commercial or subsistence fishing practices. The term particularly applies to coastal or island ethnic groups using traditional techniques such as rod and tackle, arrows and harpoons, throw nets and drag nets, and traditional...
stake-net traps
Fish trap
A fish trap is a trap used for fishing. Fish traps may have the form of a fishing weir or a lobster trap. A typical trap might consist of a frame of thick steel wire in the shape of a heart, with chicken wire stretched around it. The mesh wraps around the frame and then tapers into the inside of...
), as well as in demersal trammel and trawl nets. The Arabian carpetshark forms the predominant component of the "cat shark" catch of Kuwait
Kuwait
The State of Kuwait is a sovereign Arab state situated in the north-east of the Arabian Peninsula in Western Asia. It is bordered by Saudi Arabia to the south at Khafji, and Iraq to the north at Basra. It lies on the north-western shore of the Persian Gulf. The name Kuwait is derived from the...
i prawn
Prawn
Prawns are decapod crustaceans of the sub-order Dendrobranchiata. There are 540 extant species, in seven families, and a fossil record extending back to the Devonian...
trawls, which represents the second-largest bycatch (14% of total) of the fishery
Fishery
Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...
. It is also caught off Bahrain
Bahrain
' , officially the Kingdom of Bahrain , is a small island state near the western shores of the Persian Gulf. It is ruled by the Al Khalifa royal family. The population in 2010 stood at 1,214,705, including 235,108 non-nationals. Formerly an emirate, Bahrain was declared a kingdom in 2002.Bahrain is...
and likely elsewhere. Another potentially major threat to this species is habitat degradation: coral reefs in the Persian Gulf face bottom trawling, coastal development (especially large-scale land reclamation
Land reclamation
Land reclamation, usually known as reclamation, is the process to create new land from sea or riverbeds. The land reclaimed is known as reclamation ground or landfill.- Habitation :...
projects such as in the United Arab Emirates
United Arab Emirates
The United Arab Emirates, abbreviated as the UAE, or shortened to "the Emirates", is a state situated in the southeast of the Arabian Peninsula in Western Asia on the Persian Gulf, bordering Oman, and Saudi Arabia, and sharing sea borders with Iraq, Kuwait, Bahrain, Qatar, and Iran.The UAE is a...
), Turkish
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
dam
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
s on the Tigris
Tigris
The Tigris River is the eastern member of the two great rivers that define Mesopotamia, the other being the Euphrates. The river flows south from the mountains of southeastern Turkey through Iraq.-Geography:...
-Euphrates
Euphrates
The Euphrates is the longest and one of the most historically important rivers of Western Asia. Together with the Tigris, it is one of the two defining rivers of Mesopotamia...
river system, draining of marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....
es in Iraq
Iraq
Iraq ; officially the Republic of Iraq is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....
, and oil spill
Oil spill
An oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially marine areas, due to human activity, and is a form of pollution. The term is mostly used to describe marine oil spills, where oil is released into the ocean or coastal waters...
s. Coastal habitats off India are also similarly pressured. As both fishing and habitat degradation are likely to intensify in the region, the International Union for Conservation of Nature (IUCN) has assessed the Arabian carpetshark as Near Threatened
Near Threatened
Near Threatened is a conservation status assigned to species or lower taxa that may be considered threatened with extinction in the near future, although it does not currently qualify for the threatened status...
.