:''"Sharpnose stingray" may also refer to '' Telatrygon zugei'', '' Maculabatis gerrardi'', or '' Pateobatis jenkinsii. The sharpnose stingray (''Telatrygon acutirostra'') is a little-known

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

stingray Stingrays are a group of sea Batoidea, rays, a type of cartilaginous fish. They are classified in the suborder Myliobatoidei of the order Myliobatiformes and consist of eight families: Hexatrygonidae (sixgill stingray), Plesiobatidae (deepwate ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Dasyatidae, found off southern

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

and in the

East China Sea The East China Sea is a marginal sea of the Western Pacific Ocean, located directly offshore from East China. China names the body of water along its eastern coast as "East Sea" (, ) due to direction, the name of "East China Sea" is otherwise ...

. With a rounded

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

disc and a long, projecting snout, ''T. acutirostra'' resembles (and was historically confused with) the smaller pale-edged stingray (''T. zugei''). A number of characteristics differentiate this species from ''T. zugei'', including larger eyes and the absence of a dorsal fin fold on the tail. The

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

(IUCN) has assessed this species as Vulnerable, as its restricted distribution renders it vulnerable to increases in fishing pressure.

Taxonomy

Prior to being scientifically described, ''T. acutirostra'' has been confused for ''T. zugei''; the two species have been confounded by various authors since at least Jordan and Fowler's 1903 review of Japanese

elasmobranch Elasmobranchii () is a subclass of Chondrichthyes or cartilaginous fish, including modern sharks ( division Selachii), and batomorphs (division Batomorphi, including rays, skates, and sawfish). Members of this subclass are characterised by h ...

s. In 1988, Kiyonori Nishida and Kazuhiro Nakaya published a study of the ''T. zugei''

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

with a description of ''T. acutirostra'', in the ''Japanese Journal of Ichthyology''. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

comes from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''acuti'' ("sharp") and ''rostra'' ("snout"). The

type specimen In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...

is an adult male across, trawled from the

Distribution and habitat

''Telatrygon acutirostra'' is known from off southern Japan and in the East China Sea at a depth of , though there is also a possible record of this species from the

Gulf of Guayaquil The Gulf of Guayaquil is a large body of water of the Pacific Ocean in western South America. Its northern limit is the city of Santa Elena, Ecuador, Santa Elena, in Ecuador, and its southern limit is Cabo Blanco, Peru, Cabo Blanco, in Peru. The ...

off

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

. Like most other stingrays this species is

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

in nature.

Description

The

disc of ''T. acutirostra'' is about as wide as it is long, with rounded outer margins and concave leading margins merging with a long, triangular snout. The eyes are small and followed by larger spiracles. There is a curtain of skin between the nares, with a fringed, straight posterior margin. The mouth is slightly curved and lacks

papilla Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Papilla (worms), small bumps on the surface of certain worms * Basilar papilla, a sensory organ of lizards, amphibians and fish * ...

e on the floor. There are 40–51 upper tooth rows and 39–49 lower tooth rows, arranged with a

quincunx A quincunx ( ) is a geometry, geometric pattern consisting of five points arranged in a cross, with four of them forming a Square (geometry), square or rectangle and a fifth at its center. The same pattern has other names, including "in saltire" ...

pattern into pavement-like surfaces. The teeth of adult males have pointed cusps unlike in juveniles and females. The

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...

s are wide and triangular. The tail is whip-like and longer than the disc, and bears 1-2 stinging spines on the upper surface. A subtle dorsal keel and low ventral fin fold are present behind the spine. There is a row of 30 tubercles along the midline of the back, and another row of 16 tubercles in front of the spine. The tail behind the spine is covered by small denticles. The coloration is light brown above and white below. The largest known specimen has a disc width of . This species can be distinguished from the similar ''T. zugei'' by a larger

eyeball An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the eye ...

size, the absence of a dorsal fin fold on the tail, a larger maturation size, and various

meristic Meristics is an area of zoology and botany which relates to counting quantitative features of animals and plants, such as the number of fins or scales in fish. A meristic (countable trait) can be used to describe a particular species, or used to i ...

characters.

Biology and ecology

Virtually nothing is known of the natural history of ''T. acutirostra''. One male specimen was immature, while another across was mature. It is presumably

aplacental viviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop inside eggs that rema ...

like other stingrays.

Human interactions

''Telatrygon acutirostra'' likely forms part of coastal

bottom trawl Bottom trawling is trawling (towing a trawl, which is a fishing net) along the seafloor. It is also referred to as "dragging". The scientific community divides bottom trawling into benthic trawling and Demersal zone, demersal trawling. Benthic tra ...

and set net

fishery Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place ( a.k.a., fishing grounds). Commercial fisheries include wild fisheries and fish far ...

catches operating off Japan and elsewhere, though specific utilization data is required. The

(IUCN) has assessed this species as Vulnerable, as it would be highly susceptible to increasing fishing pressure given its possibly limited geographic distribution.

References

{{Taxonbar, from=Q135580 Dasyatidae Taxa named by Kiyonori Nishida Taxa named by Kazuhiro Nakaya Fish described in 1988 sharpnose stingray