Coral catshark
Encyclopedia
The coral catshark is a species
of catshark
, family
Scyliorhinidae. It is common on shallow coral reef
s across the Indo-West Pacific
, from Pakistan
to New Guinea
. Reaching 70 cm (27.6 in) in length, the coral catshark has an extremely slender body, a short head and tail, and two dorsal fin
s that are angled backwards. It can be identified by the numerous black and white spots on its back, sides, and fins, which often merge to form horizontal bars. Furthermore, adult males have distinctively long and thin claspers.
Reclusive and inactive during the day, at dusk
and at night the coral catshark actively forages for small, bottom-living invertebrate
s and bony fishes. Its slender form allows it to access tight spaces on the reef. It is oviparous: females lay purse-shaped egg capsules two at a time on the bottom, and the young hatch after 4–6 months. This small, harmless shark adapts well to captivity and has reproduced in the aquarium
; it is regarded as one of the most suitable shark species for private aquarists
. The coral catshark is a minor bycatch
of reef fisheries, with minimal commercial value. There is increasing fishing activity and extensive habitat degradation within its range, leading to concern over its population and its assessment as Near Threatened
by the International Union for Conservation of Nature (IUCN).
, in the 1830 Memoir of the Life and Public Services of Sir Thomas Stamford Raffles. Its original name was Scyllium marmoratum, from the Latin
marmoratus meaning "marbled". Hence, another common name
for this species is marbled catshark. In 1913, Samuel Garman placed it in his newly created genus
Atelomycterus
. The type specimen was caught off Sumatra
and is suspected to have been lost.
and India
to Southeast Asia
and Taiwan
, including the Philippines
and New Guinea
. Its range extends as far north as the Ryukyu Islands
. Early records from Australia
n waters are in fact of the related Australian marbled catshark
(A. macleayi) and banded sand catshark
(A. fasciatus). Common and bottom-dwelling in nature, the coral catshark inhabits inshore coral reef
s at depths not exceeding 15 m (49.2 ft).
s; behind are spiracle
s of moderate size. The large nostrils are mostly covered by broad, triangular flaps of skin on their anterior margins, leaving small incurrent and excurrent openings. The nasal flaps reach the mouth, obscuring a pair of broad grooves connecting the excurrent openings and the mouth. The long, angular mouth has very long furrows at the corners extending onto both the upper and lower jaws. The small teeth have a narrow central cusp flanked by 1–2 cusplets on both sides. There are five pairs of gill slit
s.
The pectoral fins are fairly large. The first dorsal fin
is angled backwards and originates over the rear of the pelvic fin bases; the second dorsal fin is similarly shaped and slightly smaller than the first, and originates over the front quarter of the anal fin base. Adult males have thin, tapering claspers that extend about two-thirds of the distance between the pelvic and anal fins. The anal fin is much smaller than the dorsal fins. The caudal fin is relatively short and broad, with an indistinct lower lobe and a ventral notch near the tip of the upper lobe. The skin is thick and covered by well-calcified
dermal denticles. Extremely variable in coloration, the coral catshark lacks prominent saddle markings but rather has many black and white spots on a grayish background. These spots often run together to form horizontal dashes, which include white tips on the dorsal fins and a white stripe through the gill slits. The underside is plain white. This species grows up to 70 cm (27.6 in) long.
(Hemiscyllium ocellatum). It is primarily crepuscular
and nocturnal, with active foraging activity beginning in the afternoon and ending before sunrise. During the day, it generally hides under shelter such as reef overhangs or sunken logs, either singly or in groups. Individual sharks may return to the same hiding place on successive days. This species feeds on small benthic invertebrate
s and bony fishes; captive specimens have been observed lying still and lunging at prey that come into range.
The coral catshark is oviparous, with the female producing eggs two at a time. Each egg is enclosed in a purse-shaped capsule roughly 6–8 cm (2.4–3.1 in) long and 2 cm (0.78740157480315 in) wide, with two constricted "waists"; one end of the capsule is squared off while the other bears two short "horns" that may terminate in short tendrils. The female deposits the eggs on the bottom, rather than attaching them to vertical structures. The capsule is light brown when freshly laid and darkens over time. The eggs hatch in 4–6 months at 26 °C (78.8 °F). Newly hatched sharks measure 10–13 cm (3.9–5.1 in) long and have a contrasting dorsal pattern of light and dark vertical bars, sometimes with black and white dots. At three months old, the young have grown by 4–5 cm (1.6–2 in) and their coloration has faded to match that of the adults. Males and females attain sexual maturity
at around 47–62 cm (18.5–24.4 in) and 49–57 cm (19.3–22.4 in) respectively.
, the coral catshark is regarded as well-suited to home aquariums because of its small size, hardiness, and attractive appearance. It requires a tank at least 3 m (9.8 ft) long, with sufficiently deep hiding places. This shark tends to be more aggressive than other small sharks, often attacking tankmates larger than it can consume. Captive individuals have been known to live up to 20 years, and the species has reproduced in the aquarium. Small numbers of coral catsharks are caught incidentally
by artisanal reef fishers in eastern Indonesia
and likely elsewhere; it may be sold for meat or processed for fishmeal and liver oil
, but its size limits its economic importance. The International Union for Conservation of Nature (IUCN) has assessed this species as Near Threatened
, and notes that with more data it may meet the criteria for Vulnerable
. It is likely threatened by the rising fishing pressure throughout its range, as well as by widespread habitat degradation from blast fishing
, pollution
, and the mining of coral for use as building material.
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 catshark
Catshark
Catsharks are ground sharks of the family Scyliorhinidae, with over 150 known species. While they are generally known as catsharks, many species are commonly called dogfish....
, 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...
Scyliorhinidae. It is common on shallow 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 across the Indo-West Pacific
Indo-West Pacific
The Indo-West Pacific, or IWP, is a zoogeographical region spanning the entire Indian Ocean including the Red Sea and the Pacific Ocean as far as the Caroline Islands but short of the Marshall Islands...
, from 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...
to New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
. Reaching 70 cm (27.6 in) in length, the coral catshark has an extremely slender body, a short head and tail, and 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 that are angled backwards. It can be identified by the numerous black and white spots on its back, sides, and fins, which often merge to form horizontal bars. Furthermore, adult males have distinctively long and thin claspers.
Reclusive and inactive during the day, at dusk
Crepuscular
Crepuscular animals are those that are active primarily during twilight, that is during dawn and dusk. The word is derived from the Latin word crepusculum, meaning "twilight." Crepuscular is, thus, in contrast with diurnal and nocturnal behavior. Crepuscular animals may also be active on a bright...
and at night the coral catshark actively forages for small, bottom-living 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 and bony fishes. Its slender form allows it to access tight spaces on the reef. It is oviparous: females lay purse-shaped egg capsules two at a time on the bottom, and the young hatch after 4–6 months. This small, harmless shark adapts well to captivity and has reproduced in the aquarium
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
; it is regarded as one of the most suitable shark species for private aquarists
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:...
. The coral catshark is a minor 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...
of reef fisheries, with minimal commercial value. There is increasing fishing activity and extensive habitat degradation within its range, leading to concern over its population and its assessment 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).
Taxonomy
The coral catshark was first described by an anonymous author, usually referred to English zoologist Edward Turner BennettEdward Turner Bennett
Edward Turner Bennett was an English zoologist and writer. He was the elder brother of the botanist John Joseph Bennett. Bennett was born at Hackney and practiced as a surgeon, but his chief pursuit was always zoology...
, in the 1830 Memoir of the Life and Public Services of Sir Thomas Stamford Raffles. Its original name was Scyllium marmoratum, from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
marmoratus meaning "marbled". Hence, another 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...
for this species is marbled catshark. In 1913, Samuel Garman placed it in his newly created genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Atelomycterus
Atelomycterus
Atelomycterus is a genus of catshark, family Scyliorhinidae.-Species:* Atelomycterus baliensis W. T. White, Last & Dharmadi, 2005 * Atelomycterus fasciatus Compagno & Stevens, 1993...
. The type specimen was caught off Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
and is suspected to have been lost.
Distribution and habitat
The most widely distributed member of its genus, the coral catshark can be found from PakistanPakistan
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 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...
to Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
and Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
, including the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
and New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
. Its range extends as far north as the Ryukyu Islands
Ryukyu Islands
The , also known as the , is a chain of islands in the western Pacific, on the eastern limit of the East China Sea and to the southwest of the island of Kyushu in Japan. From about 1829 until the mid 20th century, they were alternately called Luchu, Loochoo, or Lewchew, akin to the Mandarin...
. Early records from Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n waters are in fact of the related Australian marbled catshark
Australian marbled catshark
The Australian marbled catshark, Atelomycterus macleayi, is a catshark of the family Scyliorhinidae found in the eastern Indian Ocean endemic to Western Australia between latitudes 12° S and 21° S, from the surface to 245 m. Its length is up to 60 cm....
(A. macleayi) and banded sand catshark
Banded sand catshark
The banded sand catshark, Atelomycterus fasciatus, is a catshark of the family Scyliorhinidae found in the Indo-West Pacific Ocean endemic to northern Australia between latitudes 10° S and 21° S, at depths of between 27 and 120 m. Its length is up to 45 cm....
(A. fasciatus). Common and bottom-dwelling in nature, the coral catshark inhabits inshore 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 at depths not exceeding 15 m (49.2 ft).
Description
The coral catshark has a very slender, cylindrical, firm body and a short, narrow head. The snout is short and slightly flattened, with a blunt tip. The eyes are horizontally oval and protected by rudimentary nictitating membraneNictitating membrane
The nictitating membrane is a transparent or translucent third eyelid present in some animals that can be drawn across the eye for protection and to moisten it while maintaining visibility. Some reptiles, birds, and sharks have a full nictitating membrane; in many mammals, there is a small...
s; behind are 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...
s of moderate size. The large nostrils are mostly covered by broad, triangular flaps of skin on their anterior margins, leaving small incurrent and excurrent openings. The nasal flaps reach the mouth, obscuring a pair of broad grooves connecting the excurrent openings and the mouth. The long, angular mouth has very long furrows at the corners extending onto both the upper and lower jaws. The small teeth have a narrow central cusp flanked by 1–2 cusplets on both sides. There are 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.
The pectoral fins are fairly large. The first 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...
is angled backwards and originates over the rear of the pelvic fin bases; the second dorsal fin is similarly shaped and slightly smaller than the first, and originates over the front quarter of the anal fin base. Adult males have thin, tapering claspers that extend about two-thirds of the distance between the pelvic and anal fins. The anal fin is much smaller than the dorsal fins. The caudal fin is relatively short and broad, with an indistinct lower lobe and a ventral notch near the tip of the upper lobe. The skin is thick and covered by well-calcified
Calcification
Calcification is the process in which calcium salts build up in soft tissue, causing it to harden. Calcifications may be classified on whether there is mineral balance or not, and the location of the calcification.-Causes:...
dermal denticles. Extremely variable in coloration, the coral catshark lacks prominent saddle markings but rather has many black and white spots on a grayish background. These spots often run together to form horizontal dashes, which include white tips on the dorsal fins and a white stripe through the gill slits. The underside is plain white. This species grows up to 70 cm (27.6 in) long.
Biology and ecology
The elongated body of the coral catshark allows it to move into and through small spaces in the reef environment, though it does not "crawl" using its pectoral and pelvic fins like the epaulette sharkEpaulette shark
The epaulette shark is a species of longtailed carpet shark, family Hemiscylliidae, found in shallow, tropical waters off Australia and New Guinea . The common name of this shark comes from the very large, white-margined black spot behind each pectoral fin, which are reminiscent of military...
(Hemiscyllium ocellatum). It is primarily crepuscular
Crepuscular
Crepuscular animals are those that are active primarily during twilight, that is during dawn and dusk. The word is derived from the Latin word crepusculum, meaning "twilight." Crepuscular is, thus, in contrast with diurnal and nocturnal behavior. Crepuscular animals may also be active on a bright...
and nocturnal, with active foraging activity beginning in the afternoon and ending before sunrise. During the day, it generally hides under shelter such as reef overhangs or sunken logs, either singly or in groups. Individual sharks may return to the same hiding place on successive days. This species feeds on small benthic 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 and bony fishes; captive specimens have been observed lying still and lunging at prey that come into range.
The coral catshark is oviparous, with the female producing eggs two at a time. Each egg is enclosed in a purse-shaped capsule roughly 6–8 cm (2.4–3.1 in) long and 2 cm (0.78740157480315 in) wide, with two constricted "waists"; one end of the capsule is squared off while the other bears two short "horns" that may terminate in short tendrils. The female deposits the eggs on the bottom, rather than attaching them to vertical structures. The capsule is light brown when freshly laid and darkens over time. The eggs hatch in 4–6 months at 26 °C (78.8 °F). Newly hatched sharks measure 10–13 cm (3.9–5.1 in) long and have a contrasting dorsal pattern of light and dark vertical bars, sometimes with black and white dots. At three months old, the young have grown by 4–5 cm (1.6–2 in) and their coloration has faded to match that of the adults. Males and females attain 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...
at around 47–62 cm (18.5–24.4 in) and 49–57 cm (19.3–22.4 in) respectively.
Human interactions
Common in the aquarium tradeFishkeeping
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:...
, the coral catshark is regarded as well-suited to home aquariums because of its small size, hardiness, and attractive appearance. It requires a tank at least 3 m (9.8 ft) long, with sufficiently deep hiding places. This shark tends to be more aggressive than other small sharks, often attacking tankmates larger than it can consume. Captive individuals have been known to live up to 20 years, and the species has reproduced in the aquarium. Small numbers of coral catsharks are caught 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...
by artisanal reef fishers in eastern Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
and likely elsewhere; it may be sold for meat or processed for fishmeal and liver oil
Shark liver oil
Shark liver oil is obtained from sharks that are caught for food purposes and are living in cold, deep oceans. The liver oil from sharks has been used by fishermen for centuries as a folk remedy for general health...
, but its size limits its economic importance. The International Union for Conservation of Nature (IUCN) has assessed this species 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...
, and notes that with more data it may meet the criteria for Vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
. It is likely threatened by the rising fishing pressure throughout its range, as well as by widespread habitat degradation from blast fishing
Blast fishing
Blast fishing or dynamite fishing is the practice of using explosives to stun or kill schools of fish for easy collection. This often illegal practice can be extremely destructive to the surrounding ecosystem, as the explosion often destroys the underlying habitat that supports the fish...
, pollution
Water pollution
Water pollution is the contamination of water bodies . Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds....
, and the mining of coral for use as building material.