Pondicherry shark
Encyclopedia
The Pondicherry shark is a very rare and little-known species
of requiem shark
, family
Carcharhinidae. It is mostly found in coastal and possibly brackish waters around the Indian subcontinent
and Southeast Asia
. This shark is small and stocky, with a rather long snout and a large first dorsal fin
that is placed forward on the body and has a long rear tip. It is gray above and white below, with black-tipped pectoral, second dorsal, and caudal fins. Not seen since 1979, this species is listed as Critically Endangered
by the International Union for Conservation of Nature (IUCN), and may be extinct.
originally described the Pondicherry shark as Carcharias (Hypoprion) hemiodon, based on a 47 cm (18.5 in) long immature male from Pondicherry, India
and three more paratype
s from the same region. He published his account in Johannes Peter Müller
and Friedrich Gustav Jakob Henle
's 1841 Systematische Beschreibung der Plagiostomen. In 1862, Theodore Gill
proposed that this species be placed in a new genus, Hypoprionodon, based on the relative position of the dorsal
and pectoral fins, though this was not generally accepted. Later authors have recognized Hypoprion as a synonym
of Carcharhinus. Another common name
for this species is long nosed shark. The evolutionary relationships of this species are uncertain. In 1988, Leonard Compagno
placed it in an informal phenetic group also containing the smalltail shark
(C. porosus), blackspot shark
(C. sealei), spottail shark
(C. sorrah), creek whaler
(C. fitzroyensis), whitecheek shark
(C. dussumieri), the Borneo shark
(C. borneensis), and the hardnose shark
(C. macloti).
region; it has been found at a handful of widely separated locations from the Gulf of Oman
, India
, and the Indonesia
n islands of Borneo
and Java
. There are also less reliable records from around the South China Sea
, New Guinea
, and northern Australia
. It inhabits inshore waters and has been reported from brackish water
in the lower stretches of the Hooghli and the Saigon River
, though this remains to be verified.
is a broad slit preceded by a small, nipple-shaped flap of skin. The eyes are large and circular. The mouth is arched, without prominent furrows at the corners. There are 12–14 tooth rows on each side of both jaws, in addition to 1–2 small teeth at the symphysis (center). The teeth have a single narrow cusp, with those in the upper jaw wider and more angled than those in the lower jaw, and sometimes weakly serrated.
The pectoral fins are short and falcate (sickle-shaped) with pointed tips, originating below the fourth gill slit
. The first dorsal fin is tall, with a distinctive long free rear tip, and originates just behind the pectoral fin insertions. The second dorsal fin is long but low, and positioned about opposite the anal fin. There is a low ridge between the dorsal fins. The dermal denticles are oval and overlapping, with three (sometimes five) horizontal ridges leading to small marginal teeth. This species is plain gray above and white below, which extends in an obvious band onto the flanks. The pectoral, second dorsal, and caudal fins are tipped in black, while the other fins darken toward the margins. The maximum size is uncertain due to a lack of large specimens, but probably does not much exceed 1 m (3.3 ft).
s, and crustacean
s. It is presumably viviparous like other members of its family, with newborns measuring under 32 cm (12.6 in) long.
and commercial fisheries
in the Indo-Australian region. The International Union for Conservation of Nature (IUCN) has listed it as Critically Endangered
.
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 requiem shark
Requiem shark
Requiem sharks are a family, Carcharhinidae, of sharks in the order Carcharhiniformes, containing migratory, live-bearing sharks of warm seas such as the tiger shark, the blue shark, the bull shark, and the milk shark.The name may be related to the French word for shark, "requin", itself of...
, 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...
Carcharhinidae. It is mostly found in coastal and possibly brackish waters around the Indian subcontinent
Indian subcontinent
The Indian subcontinent, also Indian Subcontinent, Indo-Pak Subcontinent or South Asian Subcontinent is a region of the Asian continent on the Indian tectonic plate from the Hindu Kush or Hindu Koh, Himalayas and including the Kuen Lun and Karakoram ranges, forming a land mass which extends...
and 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...
. This shark is small and stocky, with a rather long snout and a large 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...
that is placed forward on the body and has a long rear tip. It is gray above and white below, with black-tipped pectoral, second dorsal, and caudal fins. Not seen since 1979, this species is listed as Critically Endangered
Critically Endangered
Critically Endangered is the highest risk category assigned by the IUCN Red List for wild species. Critically Endangered means that a species' numbers have decreased, or will decrease, by 80% within three generations....
by the International Union for Conservation of Nature (IUCN), and may be extinct.
Taxonomy and phylogeny
French zoologist Achille ValenciennesAchille Valenciennes
Achille Valenciennes was a French zoologist.Valenciennes was born in Paris, and studied under Georges Cuvier. Valenciennes' study of parasitic worms in humans made an important contribution to the study of parasitology...
originally described the Pondicherry shark as Carcharias (Hypoprion) hemiodon, based on a 47 cm (18.5 in) long immature male from Pondicherry, 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...
and three more paratype
Paratype
Paratype is a technical term used in the scientific naming of species and other taxa of organisms. The exact meaning of the term paratype when it is used in zoology is not the same as the meaning when it is used in botany...
s from the same region. He published his account in Johannes Peter Müller
Johannes Peter Müller
Johannes Peter Müller , was a German physiologist, comparative anatomist, and ichthyologist not only known for his discoveries but also for his ability to synthesize knowledge.-Early years and education:...
and Friedrich Gustav Jakob Henle
Friedrich Gustav Jakob Henle
Friedrich Gustav Jakob Henle was a German physician, pathologist and anatomist. He is credited with the discovery of the loop of Henle in the kidney. His essay "On Miasma and Contagia" was an early argument for the germ theory of disease...
's 1841 Systematische Beschreibung der Plagiostomen. In 1862, Theodore Gill
Theodore Gill
Theodore Nicholas Gill was an American ichthyologist, mammalogist, malacologist and librarian.Born and educated in New York City under private tutors, Gill early showed interest in natural history. He was associated with J...
proposed that this species be placed in a new genus, Hypoprionodon, based on the relative position of the dorsal
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...
and pectoral fins, though this was not generally accepted. Later authors have recognized Hypoprion as a synonym
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
of Carcharhinus. 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 long nosed shark. The evolutionary relationships of this species are uncertain. In 1988, Leonard Compagno
Leonard Compagno
Leonard Joseph Victor Compagno is an international authority on shark taxonomy and the author of many scientific papers and books on the subject, best known of which is his 1984 catalogue of shark species produced for the Food and Agriculture Organization of the United Nations.-Career:*Ph.D,...
placed it in an informal phenetic group also containing the smalltail shark
Smalltail shark
The smalltail shark is a species of requiem shark, family Carcharhinidae, found in the western Atlantic Ocean from the northern Gulf of Mexico to southern Brazil. It inhabits shallow waters close to shore, particularly over muddy bottoms around estuaries. It tends to swim low in the water column...
(C. porosus), blackspot shark
Blackspot shark
The blackspot shark, Carcharhinus sealei, is a requiem shark of the family Carcharhinidae, found in the Indo-West Pacific oceans between latitudes 24° N and 30° S, from the surface to 40 m. Its length is up to about 1.5 m....
(C. sealei), spottail shark
Spottail shark
The spottail shark is a species of requiem shark, family Carcharhinidae, found in the Indo-West Pacific oceans waters between latitudes 31° N and 31° S, from the surface to 140 m. Its length is up to about 1.6 m....
(C. sorrah), creek whaler
Creek whaler
The creek whaler, Carcharhinus fitzroyensis, is a requiem shark of the family Carcharhinidae, found in the southwestern Pacific Ocean between latitudes 10° S and 26° S, from the surface to at least 40 m. Its length is up to about 1.35 m....
(C. fitzroyensis), whitecheek shark
Whitecheek shark
The whitecheek shark, Carcharhinus dussumieri, is a requiem shark of the family Carcharhinidae, found in the Indo-West Pacific Ocean between latitudes 34° N and 25° S. Its length is up to about 1.2 m....
(C. dussumieri), the Borneo shark
Borneo shark
The Borneo shark is a very rare and little-known species of requiem shark, family Carcharhinidae, found in the shallow coastal waters of northwestern Borneo and possibly elsewhere in Southeast Asia. A small shark reaching in length, this species is the only member of its genus with enlarged pores...
(C. borneensis), and the hardnose shark
Hardnose shark
The hardnose shark is a species of requiem shark, family Carcharhinidae, found in the Indo-West Pacific oceans between latitudes 26° N and 11° S, from the surface to 170 m. Its length is up to about 1.1 m....
(C. macloti).
Distribution and habitat
The Pondicherry shark was apparently broadly distributed in the Indo-PacificIndo-Pacific
The Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia...
region; it has been found at a handful of widely separated locations from the Gulf of Oman
Gulf of Oman
The Gulf of Oman or Sea of Oman is a strait that connects the Arabian Sea with the Strait of Hormuz, which then runs to the Persian Gulf. It is generally included as a branch of the Persian Gulf, not as an arm of the Arabian Sea. On the north coast is Pakistan and Iran...
, 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...
, and the 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...
n islands of Borneo
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
and Java
Java
Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...
. There are also less reliable records from around the South China Sea
South China Sea
The South China Sea is a marginal sea that is part of the Pacific Ocean, encompassing an area from the Singapore and Malacca Straits to the Strait of Taiwan of around...
, 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...
, and northern 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...
. It inhabits inshore waters and has been reported from brackish water
Brackish water
Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...
in the lower stretches of the Hooghli and the Saigon River
Saigon River
The Saigon River is a river located in southern Vietnam that rises near Phum Daung in southeastern Cambodia, flows south and south-southeast for about 140 miles and empties into the Nha Be River, which in its turn empties into the South China Sea some 20 km north-east of the Mekong Delta.The...
, though this remains to be verified.
Description
The Pondicherry shark is rather thick-bodied, with a moderately long, pointed snout. Each 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...
is a broad slit preceded by a small, nipple-shaped flap of skin. The eyes are large and circular. The mouth is arched, without prominent furrows at the corners. There are 12–14 tooth rows on each side of both jaws, in addition to 1–2 small teeth at the symphysis (center). The teeth have a single narrow cusp, with those in the upper jaw wider and more angled than those in the lower jaw, and sometimes weakly serrated.
The pectoral fins are short and falcate (sickle-shaped) with pointed tips, originating below the fourth 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...
. The first dorsal fin is tall, with a distinctive long free rear tip, and originates just behind the pectoral fin insertions. The second dorsal fin is long but low, and positioned about opposite the anal fin. There is a low ridge between the dorsal fins. The dermal denticles are oval and overlapping, with three (sometimes five) horizontal ridges leading to small marginal teeth. This species is plain gray above and white below, which extends in an obvious band onto the flanks. The pectoral, second dorsal, and caudal fins are tipped in black, while the other fins darken toward the margins. The maximum size is uncertain due to a lack of large specimens, but probably does not much exceed 1 m (3.3 ft).
Biology and ecology
Virtually nothing is known of the natural history of the Pondicherry shark. Its diet likely consists of small bony fishes, cephalopodCephalopod
A cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...
s, and crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s. It is presumably viviparous like other members of its family, with newborns measuring under 32 cm (12.6 in) long.
Human interactions
Extremely rare, fewer than 20 specimens of the Pondicherry shark have been deposited in museum collections, most of which were collected prior to 1900. Despite detailed market surveys across much of its presumed range, the last confirmed sighting of the Pondicherry shark was in 1979 and it is feared to be extinct. If it still survives, it would be heavily pressured by expanding, unregulated artisanalArtisan 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...
and commercial fisheries
Commercial fishing
Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions...
in the Indo-Australian region. The International Union for Conservation of Nature (IUCN) has listed it as Critically Endangered
Critically Endangered
Critically Endangered is the highest risk category assigned by the IUCN Red List for wild species. Critically Endangered means that a species' numbers have decreased, or will decrease, by 80% within three generations....
.