Honeycomb whipray
Encyclopedia
The honeycomb whipray is a species
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 stingray
Myliobatiformes
Myliobatiformes is one of the four orders of batoids, cartilaginous fishes related to sharks. They were formerly included in the order Rajiformes, but more recent phylogenetic studies have shown that the myliobatiforms are a monophyletic group, and that its more derived members evolved their...

 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...

 Dasyatidae, found widely in the shallow coastal waters of the Indo-Pacific
Indo-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...

 from 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 the Malay Archipelago
Malay Archipelago
The Malay Archipelago refers to the archipelago between mainland Southeastern Asia and Australia. The name was derived from the anachronistic concept of a Malay race....

. This large species grows to 1.3 m (4.3 ft) across and has a diamond-shaped disc with rounded corners and a projecting, pointed snout. Its tail is long and whip-like, without fin folds. Adults have a striking dorsal color pattern consisting of large, dark brown rings and reticulations delineated by thin yellow lines, while juveniles have a pattern of large dark spots. This ray can also be distinguished from its similar relatives by an enlarged, pearl
Pearl
A pearl is a hard object produced within the soft tissue of a living shelled mollusk. Just like the shell of a mollusk, a pearl is made up of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other...

-like dermal denticle at the center of the back, which is followed by a few thorns. The International Union for Conservation of Nature (IUCN) has assessed the honeycomb whipray as 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:...

, as it faces heavy fishing pressure and habitat degradation across much of its range.

Taxonomy

Dutch ichthyologist Pieter Bleeker
Pieter Bleeker
Pieter Bleeker was a Dutch medical doctor and ichthyologist, famous for his work on the fishes of East Asia – Atlas Ichthyologique des Orientales Neerlandaises – which was published 1862–1877....

 first referenced the honeycomb whipray as Trygon undulata, in a 1950 list of 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...

nese fishes. Two years later, he formally described the species in the scientific journal
Scientific journal
In academic publishing, a scientific journal is a periodical publication intended to further the progress of science, usually by reporting new research. There are thousands of scientific journals in publication, and many more have been published at various points in the past...

 Verhandelingen van het Bataviaasch Genootschap van Kunsten en Wetenschappen (Memoirs of the Batavian Society of Arts and Sciences), based on three specimens caught off Jakarta
Jakarta
Jakarta is the capital and largest city of Indonesia. Officially known as the Special Capital Territory of Jakarta, it is located on the northwest coast of Java, has an area of , and a population of 9,580,000. Jakarta is the country's economic, cultural and political centre...

 and Semarang
Semarang
- Economy :The western part of the city is home to many industrial parks and factories. The port of Semarang is located on the north coast and it is the main shipping port for the province of Central Java. Many small manufacturers are located in Semarang, producing goods such as textiles,...

. Later authors assigned it to the genus Himantura. 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 ray include Bleeker's variegate ray and ocellate whipray.

The reticulate whipray (H. uarnak) and the leopard whipray
Leopard whipray
The leopard whipray is a little-known species of stingray in the family Dasyatidae, found in the Indian and Pacific Oceans from South Africa to Australia. It is found close to shore at depths shallower than , over soft substrates...

 (H. leoparda) are closely related to the honeycomb whipray. The three species are very similar in size, shape, and coloration, which has resulted in a great deal of confusion: H. undulata has often been misidentified as H. uarnak, while many references to "H. undulata" are in fact of H. leoparda, with the 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...

 H. fava used instead for the real H. undulata. The three belong to a larger 'uarnak' species complex
Species complex
A species complex is a group of closely related species, where the exact demarcation between species is often unclear or cryptic owing to their recent and usually still incomplete reproductive isolation. Ring species, superspecies and cryptic species complex are example of species complex...

 that also contains H. astra, H. fai, H. gerrardi, H. jenkinsii, and H. toshi.

Distribution and habitat

The range of the honeycomb whipray is not well-defined due to confusion with other species. It seems to occur widely in the tropical Indo-Pacific
Indo-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, from 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 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...

 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...

, but not off 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...

 (all Australian records of H. undulata appear to be H. leoparda). This benthic species inhabits inshore waters and prefers 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 with soft substrates
Substrate (marine biology)
Stream substrate is the material that rests at the bottom of a stream. There are several classification guides. One is:*Mud – silt and clay.*Sand – Particles between 0.06 and 2 mm in diameter.*Granule – Between 2 and 4 mm in diameter....

, including sandy and muddy flats, 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, and brackish estuaries and mangrove swamps.

Description

The honeycomb whipray has a diamond-shaped, rather thin pectoral fin disc slightly wider than long, with broadly rounded outer corners and concave leading margins converging on a pointed, protruding snout. The eyes are small and immediately followed by much larger 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. There is a skirt-shaped flap of skin with a finely fringed posterior margin between the long, narrow nostrils. The mouth is strongly bow-shaped, with shallow furrows at the corners, and contains a pair of papillae (nipple-shaped structures) on the floor. The teeth are small and have a low, transverse ridge on the crown. The pelvic fins are small and roughly triangular.

The tail is thin and whip-like, measuring about twice as long as the disc, and lacks fin folds. Usually a single serrated, stinging spine is placed on the dorsal surface, relatively close to the tail base. Adults have a broad band of small, flattened dermal denticles running centrally from before the eyes, over the back, onto the tail. At the center of the disc, there is an enlarged, round "pearl" denticle trailed by 2–3 smaller thorns along the midline; there are no enlarged denticles on the base of the tail. Newborns have large, well-spaced dark spots covering the disc. With age, the dorsal coloration becomes a honeycomb
Honeycomb
A honeycomb is a mass of hexagonal waxcells built by honey bees in their nests to contain their larvae and stores of honey and pollen.Beekeepers may remove the entire honeycomb to harvest honey...

-like pattern of large, nearly black rings (ocelli) and reticulations, that are separated from each other by thin yellow lines. The tail is covered by alternating dark and light bands or other markings past the sting. The underside is white. This species has been reported to a disc width of 1.3 m (4.3 ft).

Biology and ecology

Little is known of the natural history of the honeycomb whipray. It is typically encountered lying still on the bottom, often partially or completely buried in sediment. Presumably, it feeds on 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 and small fishes. Reproduction is aplacental viviparous as in other stingrays, with the mother provisioning her developing embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...

s with histotroph ("uterine milk"). Newborns measure about 26–27 cm (10.2–10.6 in) across, comparable to H. uarnak and larger than H. leoparda. Also like H. uarnak but unlike H. leoparda, by a disc width of 50 cm (19.7 in) juvenile rays have a well-developed dorsal denticle band. Males reach 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 60–70 cm (23.6–27.6 in) across.

Human interactions

Intensive commercial
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...

 and artisanal fisheries
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...

 throughout 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 elsewhere catch the honeycomb whipray, using tangle net
Tangle net
Similar to a gillnet, the tangle net, or tooth net, is a type of nylon fishing net. Left in the water for no more than two days, and allowing bycatch to be released alive, this net is considered to be less harmful that other nets. The tangle net is used in the Philippines by commercial fishermen,...

s, bottom trawls, and Danish seines, and occasionally also longlines. It is mainly marketed for its meat, though the skin and cartilage
Cartilage
Cartilage is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs...

 may also be utilized. Fishing pressure is intensifying in many portions of its range, such as the Gulf of Thailand
Gulf of Thailand
The Gulf of Thailand , also known in to Malays as Teluk Siam literally meant Gulf of Siam, is a shallow arm of the South China Sea.-Geography:...

, with this species particularly susceptible due to its inshore habits. Its habitat preferences also expose it to habitat degradation from coastal development, water 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 destructive fishing practices (i.e. 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...

). Because of these threats, the International Union for Conservation of Nature (IUCN) suspects the population of the honeycomb whipray has declined, and has assessed it as 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:...

.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK