Pelagic stingray

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Pelagic stingray
Dasyatis violacea.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Superorder: Batoidea
Order: Myliobatiformes
Family: Dasyatidae
Genus: Pteroplatytrygon
Fowler, 1910
Species:
P. violacea
Binomial name
Pteroplatytrygon violacea
(Bonaparte, 1832)
Pteroplatytrygon violacea rangemap.png
Confirmed (dark blue) and possible (light blue) range of the pelagic stingray
Synonyms
  • Dasyatis atratusIshiyama & Okada, 1955
  • Dasyatis guileriLast, 1979
  • Trygon purpureaMüller & Henle, 1841
  • Trygon violaceaBonaparte, 1832

The pelagic stingray (Pteroplatytrygon violacea) is a species of stingray in the family Dasyatidae, and the sole member of its genus. It is characterized by the wedge-like shape of its pectoral fin disc, which is much wider than long, as well as by the pointed teeth in both sexes, whip-like tail with extremely long tail spine, and uniform violet to blue-green coloration. It generally reaches 59 cm (23 in) in width. The pelagic stingray has a worldwide distribution in waters warmer than 19 °C (66 °F), and migrates seasonally to spend the summer closer to the continental shelf and at higher latitudes. The only stingray that almost exclusively inhabits the open ocean, this species is typically found in surface waters down to a depth of 100 m (330 ft). As a consequence of its midwater habits, its swimming style has evolved to feature more of a flapping motion of the pectoral fins, as opposed to the disc margin undulations used by other, bottom-dwelling stingrays.

Contents

The diet of the pelagic stingray consists of free-swimming invertebrates and bony fishes. It is an active hunter, using its pectoral fins to trap and move food to its mouth, and has been known to take advantage of seasonal feeding opportunities such as spawning squid. Like other stingrays, it is aplacental viviparous, meaning that the embryos are sustained initially by yolk and later by histotroph ("uterine milk"). With a short gestation period of 2–4 months, females may bear two litters of 4–13 pups per year. Birthing generally occurs in warm water near the equator, with the exception of the Mediterranean, with the timing varying between regions. Rarely encountered except by fishery workers, the pelagic stingray can inflict a severe, even fatal wound with its tail spine. This species is caught as bycatch throughout its range; it is of little economic value and usually discarded, often with high mortality. However, there is evidence that its numbers are increasing, perhaps owing to the heavy fishing of its natural predators and competitors (e.g., sharks). Along with the pelagic stingray's global distribution and prolific life history, this has led the International Union for Conservation of Nature (IUCN) to assess it as of Least Concern.

Taxonomy and phylogeny

The pelagic stingray was originally described by French naturalist Charles Lucien Bonaparte in the 1832 third volume of Iconografia della fauna italica per le quattro classi degli animali vertebrati. He named it Trygon violacea, from the Latin viola ("purple"), and designated two specimens collected off Italy as the species syntypes. [2] [3] The genus Trygon has since been synonymized with Dasyatis. In 1910, American zoologist Henry Weed Fowler placed the pelagic stingray in the newly created subgenus Pteroplatytrygon, from the Greek pteron ("fin"), platus ("broad"), and trygon ("stingray"). [4] Later authors elevated Pteroplatytrygon to the rank of full genus, though some taxonomists dispute whether this species is distinct enough to warrant separation from Dasyatis. [3] [5]

Taeniura lymma

Neotrygon kuhlii

Pteroplatytrygon violacea

Pastinachus sephen

Dasyatis + Indo-Pacific Himantura

Phylogenetic tree of Dasyatidae. [5] Taxon names have been updated.

Lisa Rosenberger's 2001 phylogenetic analysis, based on morphology, found that the pelagic stingray is one of the more basal members of its family, being the sister taxon to a clade that contains Pastinachus , Dasyatis , and Indo-Pacific Himantura species. [5] Other common names for the pelagic stingray include the blue stingray and the violet stingray. [6]

Distribution and habitat

The distribution of the pelagic stingray extends nearly worldwide in tropical to warm-temperate pelagic waters, between the latitudes of 52°N and 50°S. In the western Atlantic, it has been reported from the Grand Banks of Newfoundland to North Carolina, the northern Gulf of Mexico, and the Lesser Antilles, Brazil and Uruguay. In the eastern Atlantic, this species has been recorded from the North Sea to Madeira, including the Mediterranean, as well as around Cape Verde, in the Gulf of Guinea and off South Africa. In the Pacific, it is known from Japan to Australia and New Zealand in the west, British Columbia to Chile in the east, and around many oceanic islands including Hawaii, the Galápagos, and Easter Island. There have been no reports of this species from much of the Indian Ocean, but it is known to be common in the southwestern portion and around Indonesia. [1] [7] [8] [9]

The pelagic stingray is the only stingray found almost exclusively in open water. Pelagic stingray monterey.jpg
The pelagic stingray is the only stingray found almost exclusively in open water.

Unique amongst stingrays in inhabiting the open ocean rather than the sea floor, the pelagic stingray is generally found from the surface to a depth of 100 m (330 ft) over deep water. [1] It has also been caught at a depth of 330–381 m (1,083–1,250 ft) over the Kyushu–Palau Ridge, indicating that it at least occasionally approaches the bottom. [10] This species prefers water temperatures above 19 °C (66 °F), and will die if the temperature drops to 15 °C (59 °F). [7]

The pelagic stingray performs seasonal migrations following warm water masses. [3] In the northwestern Atlantic, it is found in or near the Gulf Stream from December to April, and moves north of the Stream to gather near the continental shelf from July to September. A similar migration seems to occur in the Mediterranean, though the specifics are unknown. In the Pacific, this species apparently spends the winter in oceanic waters near the equator and move into higher latitudes and towards the coast in spring. [7] Two Pacific populations are known: one migrates from near Central America to California, and the other from the central Pacific to as far as Japan and British Columbia. [3] Off southeastern Brazil, pelagic stingrays are displaced towards the coast by upwellings of cold water in late spring and summer; in some years they may even be pushed into inshore waters less than 45 m (148 ft) deep. [11]

Description

The pelagic stingray is characterized by a wedge-shaped disc much wider than long, non-protruding eyes, and dark purple coloration. Pelagic stingray2.jpg
The pelagic stingray is characterized by a wedge-shaped disc much wider than long, non-protruding eyes, and dark purple coloration.

The pelagic stingray has a very thick, distinctively wedge-shaped pectoral fin disc one-third wider than long, with broadly curved leading margins, rather angular outer corners, and nearly straight trailing margins. The snout is short with a rounded tip. The eyes are minute and, unlike in other stingrays, do not protrude above the body; the spiracles (paired respiratory openings) follow immediate behind. There is a short but broad curtain of skin between the nostrils, with a weakly fringed rear margin. The mouth is small and gently arched, with deep furrows at the corners and a tiny projection at the center of the upper jaw that fits into an indentation on the lower jaw. [12] [13] [14] There are anywhere from 0 to 15 forked papillae (nipple-like structures) in a row across the floor of the mouth. There are 25–34 upper tooth rows and 25–31 lower tooth rows; the teeth of both sexes have single, pointed cusps, but those of adult males are longer and sharper than those of adult females. [3] [12] [15] The margins of the pelvic fins are nearly straight in front and become rounded at the tips and in back. [13]

The whip-like tail measures up to twice as long as the disc; it is thick at the base and tapers significantly to the extremely long, serrated spine placed approximately one-third to halfway along its length. Two spines may be present if a replacement grows in before the original drops off. Posterior to the spine origin, there is a low ventral fin fold that does not reach to the spine tip. Young rays are completely smooth-skinned; with age small prickles appear over the center of the back, as well as a row of small thorns along the midline from between the eyes to the origin of the spine. [13] This species is a plain dark purple to blue-green above, extending onto the tail fold, and a slightly lighter shade below. When captured and handled, it exudes a thick black mucus that covers its body. [3] The pelagic stingray typically grows to 1.3 m (4.3 ft) long and 59 cm (23 in) across. [16] The largest individuals on record are from a captive rearing experiment conducted from 1995 to 2000, in which a male reached 68 cm (27 in) across and 12 kg (26 lb), and a female 94 cm (37 in) across and 49 kg (108 lb). [17]

Biology and ecology

As an adaptation for living in the open ocean, the pelagic stingray swims more by flapping than undulating its disc. Pteroplatytrygon violacea monterey.jpg
As an adaptation for living in the open ocean, the pelagic stingray swims more by flapping than undulating its disc.

In adopting a midwater lifestyle, the pelagic stingray exhibits several characteristics different from those of its bottom-dwelling relatives. While most stingrays propel themselves by undulating their disc margins, this species swims by oscillating (flapping) its pectoral fins in a manner approaching the "underwater flying" employed by eagle rays. Oscillatory fin motions generate lift, thus improving cruising efficiency in open water at a cost to maneuverability. [18] The pelagic stingray is adept at swimming backwards, which may compensate for the lower fine control offered by its swimming mode. [19]

Vision seems to be more important to the pelagic ray in finding food than in other stingrays. Compared to other members of its family, this species has less than one-third the density of electroreceptive ampullae of Lorenzini on its underside. The ampullae also cover a smaller area, though not as small as in eagle rays, and are more evenly distributed between the ventral and dorsal surfaces. This ray can detect an electric field of well under 1 nV/cm at a distance of up to 30 cm (12 in), and may be able to pick up the minute electric fields produced by moving sea water. The lateral line of the pelagic stingray, a complex system of mechanoreceptors that detect nearby movement and ocean currents, remains similar to other stingrays in covering a greater area on the ventral than the dorsal surface. However, this species is less responsive to mechanical than to visual stimuli. [19] [20] [21]

Pelagic stingrays may segregate by sex, vertically in that males are found in deeper water than females, and perhaps horizontally as well. [22] [23] Captive individuals often act highly aggressively towards ocean sunfish (Mola mola), biting and harassing them, particularly if they are hungry. [3] This species is preyed upon by oceanic whitetip sharks (Carcharhinus longimanus), great white sharks (Carcharodon carcharias), toothed whales, and other large, ocean-going carnivores. [3] [14] Its all-around dark coloration likely serves to camouflage it against its featureless habitat. [24] The venom on its tail spine is also quite potent, causing it to be avoided by other fishes. [14] Known parasites of this species include the tapeworms Acanthobothrium benedeni, A. crassicolle, and A. filicolle, Rhinebothrium baeri and R. palombii, [25] [26] and Tetragonocephalum uarnak, [27] and the monogenean Entobdella diadema. [28]

Feeding

Small fish are one of the prey types pursued by the pelagic stingray. Pelagic stingray monterey2.jpg
Small fish are one of the prey types pursued by the pelagic stingray.

The pelagic stingray is an active predator that captures prey by wrapping its pectoral fins around it, before manipulating it to the mouth. It is the only stingray in which both sexes have pointed teeth, for grasping and cutting into slippery prey. [3] [22] A wide variety of organisms are represented in its diet: crustaceans including amphipods, krill, and larval crabs, molluscs including squid, octopus, and pteropods, bony fishes including herring, mackerel, sea horses and filefish, comb jellies and medusae, and polychaete worms. [3] [22] [24] Off California, pelagic stingrays hunt large mating aggregations of squid that form from November to April. [10] Off Brazil, this species follows groups of Atlantic cutlassfish (Trichiurus lepturus) towards the coast in January and February, with both predators seeking small schooling fishes. [11] Juvenile rays consume 6–7% of their body weight in food per day, which declines to just above 1% in adults. [3]

Life history

Like other stingrays, the pelagic stingray is aplacental viviparous: the developing embryos are at first nourished by yolk, which is later supplanted by histotroph ("uterine milk", containing proteins, lipids, and mucus); the mother delivers the histotroph through numerous thread-like extensions of the uterine epithelium called "trophonemata", which feed into the enlarged spiracles of the embryo. Females have only one functional ovary and uterus, on the left, and may produce two litters per year. [10] [24] Mating occurs from March to June in the northwestern Atlantic, and in late spring in the southwestern Atlantic. [24] [29] Females are capable of storing sperm internally for more than a year, allowing them to wait for favorable environmental conditions in which to gestate their young. [3] When first passed into the uterus, a batch of fertilized eggs are contained in a single membraneous capsule tapered at both ends. Shortly after, the capsule ruptures to release the eggs, and is expelled from the uterus. [24] The gestation period may be the shortest of any shark or ray, lasting only 2–4 months, during which time the embryos increase a hundredfold in mass. [3] [10]

In the Pacific, females give birth in winter from November to March in a nursery area near Central America, prior to their northward migration. Similarly, in the northwestern Atlantic, birthing seems to occur in winter when the females are in warm southerly waters, possibly off the West Indies. However, records also exist of two possibly anomalous females that were pregnant much earlier in the year and would have given birth in August or September, before their southward migration. In the southwestern Atlantic, birthing occurs in summer around January, again in warmer water towards the equator. As opposed to other regions, in the Mediterranean females give birth in summer before moving to warmer waters. [7] The litter size ranges from 4 to 13 (average six), and does not increase with the size of the female. Newborns measure 15–25 cm (5.9–9.8 in) across. [1] [30] Rays in captivity, with ample food, grow at an average annual rate of 8.1 cm (3.2 in) (disc width), while rays in the wild grow at an average annual rate of only 1.6 cm (0.63 in). The food intake and growth rate of adults are highest in January–February and July–August, and lowest in March–April and October–November. [17] Males reach sexual maturity at 37–50 cm (15–20 in) across and two years of age, and females at 39–50 cm (15–20 in) and three years of age. [1] This species may live up to 10–12 years. One of the most prolific rays, its intrinsic population growth rate is up to 31% a year. [31]

Human interactions

A pelagic stingray at Aquamarine Fukushima, Japan; this species adapts well to captivity. Pelagic stingray fukushima.jpg
A pelagic stingray at Aquamarine Fukushima, Japan; this species adapts well to captivity.

The pelagic stingray is not aggressive and rarely encountered because of its habitat preferences, but its very long tail spine demands extreme caution be exercised in handling it. It has been responsible for two known fatalities: a worker on a tuna longliner who was impaled by a captured ray, and another fishery worker who succumbed to tetanus days after being stung. [3] This species has been kept in public aquariums for almost a century. [17]

Caught as bycatch in drifting longliners for tunas, billfishes and pelagic sharks, it is usually discarded due to its low commercial value. [32] Rays incidentally caught on longlines suffer high mortality, as fishers are wary of being stung and remove the rays from the hooks by smashing them against the side of the boat, causing severe damage to the mouth and jaws. The extent of this bycatch has yet to be quantified. [1] [6] Surveys in the Pacific suggest that pelagic stingray numbers have increased since the 1950s, possibly due to commercial fisheries depleting the dominant predators in the ecosystem, such as sharks and tuna. [33] The lack of population declines, coupled with its wide distribution and high reproductive rate, has led the International Union for Conservation of Nature (IUCN) to list this species under Least Concern. [1] [31] In June 2018 the New Zealand Department of Conservation classified the pelagic stingray as "Not Threatened" with the qualifier "Secure Overseas" under the New Zealand Threat Classification System. [34]

Recent research has been conducted into reducing pelagic stingray bycatch on longlines by switching to larger and/or C-shaped hooks. [35]

Related Research Articles

<span class="mw-page-title-main">Stingray</span> Suborder of fishes

Stingrays are a group of sea rays, which are cartilaginous fish related to sharks. They are classified in the suborder Myliobatoidei of the order Myliobatiformes and consist of eight families: Hexatrygonidae, Plesiobatidae, Urolophidae (stingarees), Urotrygonidae, Dasyatidae, Potamotrygonidae, Gymnuridae and Myliobatidae . There are about 220 known stingray species organized into 29 genera.

<span class="mw-page-title-main">Short-tail stingray</span> Species of cartilaginous fish

The short-tail stingray or smooth stingray is a common species of stingray in the family Dasyatidae. It occurs off southern Africa, typically offshore at a depth of 180–480 m (590–1,570 ft), and off southern Australia and New Zealand, from the intertidal zone to a depth of 156 m (512 ft). It is mostly bottom-dwelling in nature and can be found across a range of habitats from estuaries to reefs, but also frequently will swim into open water. One of the largest stingrays in the world, this heavy-bodied species can grow upwards of 2.1 m (6.9 ft) across and 350 kg (770 lb) in weight. Its plain-colored, diamond-shaped pectoral fin disc is characterized by a lack of dermal denticles even in adults, and white pores beside the head on either side. The body can have colors as well as dark grey or black with rows of white spots along each wing. Its tail is usually shorter than the disc and thick at the base. It is armed with large tubercles and a midline row of large thorns in front of the stinging spine which has the dorsal and ventral fin folds behind.

<span class="mw-page-title-main">Atlantic stingray</span> Species of cartilaginous fish

The Atlantic stingray is a species of stingray in the family Dasyatidae, common along the Atlantic coast of North America from Chesapeake Bay to Mexico, including brackish and freshwater habitats. It may be distinguished from other stingrays in the area by its relatively elongated snout. This species is of little commercial importance, other than for sale in the aquarium industry.

<span class="mw-page-title-main">Red stingray</span> Species of cartilaginous fish

The red stingray is a species of stingray in the family Dasyatidae, found in the northwestern Pacific Ocean off Japan, Korea, and China, and possibly elsewhere. It primarily inhabits shallow, sandy habitats close to shore, and has been known to enter brackish water. The red stingray has a diamond-shaped pectoral fin disc and gains its common name from its bright orange-red underside; there may also be patches of orange at various spots on its upper surface. Most individuals are no more than 1 m (3.3 ft) long.

<span class="mw-page-title-main">Diamond stingray</span> Species of cartilaginous fish

The diamond stingray is a species of stingray in the family Dasyatidae. It is found in the coastal waters of the eastern Pacific Ocean from southern California to northern Chile, and around the Galápagos and Hawaiian Islands. This bottom-dweller generally inhabits sandy or muddy flats near rocky reefs and kelp forests, to a depth of 30 m (98 ft), though off Hawaii it may range considerably deeper. As its common name suggests, this species has an angular, diamond-shaped pectoral fin disc that is plain brown or gray above, with rows of tubercles along the midline and on the "shoulders". The long, whip-like tail has both dorsal and ventral fin folds, which distinguish this ray from the closely similar longtail stingray. It typically grows to 1 m (3.3 ft) across.

<span class="mw-page-title-main">Estuary stingray</span> Species of cartilaginous fish

The estuary stingray, also called the estuary stingaree or brown stingray, is a species of stingray in the family Dasyatidae. Endemic to eastern Australia, it typically inhabits shallow, mangrove-lined tidal rivers, estuaries, and bays in southern Queensland and New South Wales. This yellow-brown to olive ray grows to at least 93 cm (37 in) across. It has a diamond-shaped pectoral fin disc and a mostly smooth, whip-like tail bearing both dorsal and ventral fin folds. It can additionally be identified by its long, narrow nostrils and the row of thorns along the midline of its back.

<span class="mw-page-title-main">Sharpsnout stingray</span> Species of cartilaginous fish

The sharpsnout stingray or wingfin stingray is a species of stingray in the family Dasyatidae, found from off Venezuela to northern Brazil. It inhabits shallow, brackish water, shifting towards the coast in the dry season and away from it in the rainy season. Typically measuring 70 cm (28 in) across, this dark brown ray is easily identifiable by its long, projecting snout and elongated, acutely pointed pelvic fins. Its diet consists of bottom-dwelling invertebrates. Reproduction is aplacental viviparous, with females bearing one to three pups annually. Naturally uncommon and slow-reproducing, the sharpnose stingray is under pressure by both artisanal and commercial fisheries, leading the International Union for Conservation of Nature (IUCN) to assess it as critically endangered.

<span class="mw-page-title-main">Longnose stingray</span> Species of cartilaginous fish

The longnose stingray is a species of stingray in the family Dasyatidae, native to the western Atlantic Ocean from the southern Gulf of Mexico to Brazil. Found in coastal waters no deeper than 36 m (118 ft), this demersal species favors muddy or sandy habitats. The longnose stingray is characterized by its angular, rhomboid pectoral fin disc, moderately projecting snout, and whip-like tail with a dorsal keel and ventral fin fold. It typically grows to 1.25 m (4.1 ft) across and is brownish above and light-colored below.

The Brazilian large-eyed stingray, Hypanus marianae, is a species of stingray in the family Dasyatidae. Endemic to northeastern Brazil, adults of this species inhabit shallow coral and sandstone reefs while the young are also found near beaches and in estuaries. This stingray measures up to 40 cm (16 in) across and can be identified by its large eyes, equally long fin folds above and below the tail, and distinctive coloration consisting of various dark brown markings on a yellowish-brown background above, and two pairs of dark brown blotches on a white background below. Reproduction is aplacental viviparous, with females giving birth to one young at a time, twice a year, and using sandbanks as nursery areas. The Brazilian large-eyed stingray is collected by artisanal fisheries and for the ornamental fish trade.

<span class="mw-page-title-main">Pale-edged stingray</span> Species of cartilaginous fish

The pale-edged stingray or sharpnose stingray is a species of stingray in the family Dasyatidae, found in the Indian and Pacific Oceans from India to the western Malay Archipelago and southern Japan. This bottom-dwelling ray is most commonly found over sandy areas shallower than 100 m (330 ft), as well as in estuaries. Measuring up to 29 cm (11 in) across, the pale-edged stingray has a diamond-shaped pectoral fin disc, a long projecting snout, small eyes, and a whip-like tail with both dorsal and ventral fin folds. It is chocolate brown above and white below.

The pincushion ray or thorny freshwater stingray, is a little-known species of stingray in the family Dasyatidae, found in the rivers and lakes of West and Middle Africa. A heavy-bodied ray measuring up to 1.2 m (4 ft) across, this species can be distinguished by its rounded pectoral fin disk, reduced or absent stinging tail spine, and—in adults—numerous stout thorns covering its back and tail. In lieu of a long tail spine as in other stingrays, the pincushion ray employs these thorny denticles in defense. Seldom encountered since it was originally described, this species has been assessed as Critically Endangered by the International Union for Conservation of Nature (IUCN).

<span class="mw-page-title-main">Broad stingray</span> Species of cartilaginous fish

The Broad stingray, also known as the Brown stingray or Hawaiian stingray, is a species of stingray in the family Dasyatidae. The predominant species of stingray in the inshore waters of the Hawaiian Islands, this benthic fish typically inhabits sandy or muddy flats at depths greater than 15 m (49 ft). Usually growing to 1 m (3 ft) across, the broad stingray has a wide, diamond-shaped pectoral fin disc with a protruding snout tip and a long tail with a ventral fin fold. At night, this species actively forages for bottom-dwelling invertebrates and bony fishes, often near the boundaries of reefs. Reproduction is aplacental viviparous. As substantial threats to its population exist in many areas of its wide distribution, IUCN has listed this species as Vulnerable.

<span class="mw-page-title-main">Common stingray</span> Species of cartilaginous fish

The common stingray is a species of stingray in the family Dasyatidae, found in the northeastern Atlantic Ocean and the Mediterranean and Black Seas. It typically inhabits sandy or muddy habitats in coastal waters shallower than 60 m (200 ft), often burying itself in sediment. Usually measuring 45 cm (18 in) across, the common stingray has a diamond-shaped pectoral fin disc slightly wider than long, and a whip-like tail with upper and lower fin folds. It can be identified by its plain coloration and mostly smooth skin, except for a row of tubercles along the midline of the back in the largest individuals.

<span class="mw-page-title-main">Roughtail stingray</span> Species of cartilaginous fish

The roughtail stingray is a species of stingray in the family Dasyatidae, with separate populations in coastal waters of the northwestern and southwestern Atlantic Ocean. This bottom-dwelling species typically inhabits sandy or muddy areas with patches of invertebrate cover, at a depth of 15–50 m (49–164 ft). It is seasonally migratory, overwintering in offshore waters and moving into coastal habitats for summer. The largest whip-tail stingray in the Atlantic, the roughtail stingray grows up to 2.6 m (8.5 ft) across and 360 kg (800 lb) in weight. It is plain in color, with an angular, diamond-shaped pectoral fin disc and a long, whip-like tail bearing a subtle fin fold underneath. The many thorns on its back and tail serve to distinguish it from other stingrays that share its range.

<span class="mw-page-title-main">Smalleye stingray</span> Species of cartilaginous fish

The smalleye stingray is a large species of stingray in the family Dasyatidae, measuring up to 2.2 m (7.2 ft) across. Rare but widely distributed, it is found in the Indo-Pacific from Mozambique to India to northern Australia. This species may be semi-pelagic in nature, inhabiting both deeper waters and shallow coastal reefs and estuaries. It is characterized by a diamond-shaped pectoral fin disc much wider than long, a tail that is broad and flattened in front of the spine but whip-like behind, and large white spots over its back.

<span class="mw-page-title-main">Jenkins' whipray</span> Species of cartilaginous fish

The Jenkins' whipray is a species of stingray in the family Dasyatidae, with a wide distribution in the Indo-Pacific region from South Africa to the Malay Archipelago to northern Australia. This large species grows to 1.5 m (4.9 ft) across and has a broad, diamond-shaped pectoral fin disc and a whip-like tail without fin folds. It has a band of heart-shaped dermal denticles running from between the eyes to the tail on its upper surface, along with a characteristic row of large spear-like thorns along the midline. It is uniform yellowish brown above, becoming grayish on the tail past the stinging spine, and white below; there is apparently a spotted color variant that had previously been described as a different species, the dragon stingray.

<span class="mw-page-title-main">Chinese stingray</span> Species of cartilaginous fish

The Chinese stingray, Hemitrygon sinensis, is a little-known species of stingray in the family Dasyatidae, found in the northwestern Pacific Ocean off the coasts of China and Korea. This species is characterized by a band of small dermal denticles running along the upper surface of its diamond-shaped pectoral fin disc, from the snout to the tail spine. It can grow to 40 cm (16 in) across and 82 cm (32 in) long. The Chinese stingray is taken incidentally in bottom trawls and is one of the three most commonly marketed stingrays in China. At present, the International Union for Conservation of Nature (IUCN) has assessed its conservation status as endangered.

<span class="mw-page-title-main">Pitted stingray</span> Species of cartilaginous fish

The pitted stingray is a species of stingray in the family Dasyatidae, endemic to the waters around Japan and the Sea of Japan. It typically found near the coast at depths of 40–60 m (130–200 ft), but may also venture into the open sea. Measuring up to 2 m (6.6 ft) across, the pitted stingray has a diamond-shaped pectoral fin disc with a characteristic W-shaped groove on the underside. The total length including the tail has a record of 2.8 m (9.2 ft). Other identifying characteristics of this species include its dark gray dorsal coloration with small white spots, and the presence of dorsal tubercles in adults. Pitted stingrays are caught as bycatch in coastal fisheries and brought to market. The International Union for Conservation of Nature (IUCN) does not yet have sufficient data to assess this species beyond Data Deficient. This species is now regarded as a population of the Short-tail stingray.

<span class="mw-page-title-main">Daisy stingray</span> Species of cartilaginous fish

The daisy stingray, Fontitrygon margarita, is a little-known species of stingray in the family Dasyatidae, found in shallow waters along the coast of West Africa. This species typically grows to 60 cm (24 in) across and has a rounded pectoral fin disc and a wide band of dermal denticles over its back. It is characterized by a greatly enlarged, nacreous denticle in the middle of its back called a "pearl spine"; this feature is shared with the similar but much smaller pearl stingray, which has often been confused with this species. The daisy stingray feeds mainly on crustaceans and exhibits aplacental viviparity, with litters of 1–4 young. Heavily pressured by fisheries and possibly habitat degradation, this once-common species is declining and has been assessed as Vulnerable by the International Union for Conservation of Nature (IUCN).

<span class="mw-page-title-main">Bennett's stingray</span> Species of cartilaginous fish

The Bennett's stingray or frilltailed stingray is a little-known species of stingray in the family Dasyatidae, with a wide but ill-defined distribution in the Indian and Pacific Oceans. This species is characterized by a rhomboid, yellow-brown pectoral fin disc with a fairly long snout, and an extremely long tail with a correspondingly long ventral fin fold. It measures up to 50 cm (20 in) across. It feeds on fish, and is aplacental viviparous. It is likely caught by demersal fisheries.

References

  1. 1 2 3 4 5 6 7 Kyne, P.M.; Barreto, R.; Carlson, J.; Fernando, D.; Francis, M.P.; Fordham, S.; Jabado, R.W.; Liu, K.M.; Marshall, A.; Pacoureau, N.; Romanov, E.; Sherley, R.B.; Winker, H. (2019). "Pteroplatytrygon violacea". IUCN Red List of Threatened Species . 2019: e.T161731A896169. doi: 10.2305/IUCN.UK.2019-1.RLTS.T161731A896169.en . Retrieved 20 November 2021.
  2. ↑ Eschmeyer, W. N. (ed.) violacea, Trygon Archived 2012-02-21 at the Wayback Machine . Catalog of Fishes electronic version (February 19, 2010). Retrieved on March 28, 2010.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Ebert, D.A. (2003). Sharks, Rays, and Chimaeras of California. University of California Press. pp. 219–221. ISBN   0-520-23484-7.
  4. ↑ Fowler, H.W. (April–September 1910). "Notes on Batoid Fishes". Proceedings of the Academy of Natural Sciences of Philadelphia. Academy of Natural Sciences. 62 (2): 468–475. JSTOR   4063435.
  5. 1 2 3 Rosenberger, L.J.; Schaefer, S. A. (August 6, 2001). Schaefer, S. A. (ed.). "Phylogenetic Relationships within the Stingray Genus Dasyatis (Chondrichthyes: Dasyatidae)". Copeia. 2001 (3): 615–627. doi:10.1643/0045-8511(2001)001[0615:PRWTSG]2.0.CO;2. S2CID   85657403.
  6. 1 2 Froese, Rainer; Pauly, Daniel (eds.) (2010). "Pteroplatytrygon violacea" in FishBase. March 2010 version.
  7. 1 2 3 4 Mollet, H.F. (2002). "Distribution of the pelagic stingray, Dasyatis violacea (Bonaparte, 1832), off California, Central America, and worldwide" (PDF). Marine and Freshwater Research. 53 (2): 525–530. doi:10.1071/MF02010. Archived from the original (PDF) on 2016-03-04. Retrieved 2010-04-08.
  8. ↑ Journal of Fish Biology (September 2007). "Occurrence of pelagic stingray Pteroplatytrygon violacea (Bonaparte, 1832) in the North Sea". Journal of Fish Biology. 71 (3): 933–937. doi:10.1111/j.1095-8649.2007.01534.x. Archived from the original on 2013-01-05.
  9. ↑ Debelius, H. (1997). Mediterranean and Atlantic Fish Guide. IKAN. p. 19. ISBN   3-931702-99-5.
  10. 1 2 3 4 Neer, J.A. (2008). "The Biology and Ecology of the Pelagic Stingray, Pteroplatytrygon violacea (Bonaparte, 1832)". In Camhi, M.; E.K. Pikitch; E.A. Babcock (eds.). Sharks of the Open Ocean: Biology, Fisheries and Conservation . Blackwell Science. pp.  152–159. ISBN   978-0-632-05995-9.
  11. 1 2 de Siqueira, A.E. & V.B. de Sant'Anna (2007). "Data on the pelagic stingray, Pteroplatytrygon violacea (Bonaparte, 1832) (Myliobatiformes: Dasyatidae)". Brazilian Journal of Oceanography. 55 (4): 323–325. doi: 10.1590/S1679-87592007000400008 .
  12. 1 2 Last, P.R. & J.D. Stevens (2009). Sharks and Rays of Australia (second ed.). Harvard University Press. pp. 457–458. ISBN   978-0-674-03411-2.
  13. 1 2 3 McEachran, J.D. & J.D. Fechhelm (1998). Fishes of the Gulf of Mexico: Myxiniformes to Gasterosteiformes. University of Texas Press. p. 181. ISBN   0-292-75206-7.
  14. 1 2 3 Bester, C., H.F. Mollett and J. Bourdon. Biological Profiles: Pelagic Stingray. Florida Museum of Natural History Ichthyology Department. Retrieved on November 14, 2008.
  15. ↑ Nishida, K. and K. Nakaya (1990). "Taxonomy of the genus Dasyatis (Elasmobranchii, Dasyatididae) from the North Pacific." in Pratt, H.L., S.H. Gruber and T. Taniuchi. Elasmobranchs as living resources: advances in the biology, ecology, systematics, and behaviour, and the status of fisheries. NOAA Technical Report, NMFS 90. pp. 327–346.
  16. ↑ Last, P.R. & L.J.V. Compagno (1999). "Myliobatiformes: Dasyatidae". In Carpenter, K.E. & V.H. Niem (eds.). FAO identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Food and Agricultural Organization of the United Nations. ISBN   92-5-104302-7.
  17. 1 2 3 Mollet, H.F.; J.M. Ezcurra & J.B. O'Sullivan (2002). "Captive biology of the pelagic stingray, Dasyatis violacea (Bonaparte, 1832)" (PDF). Marine and Freshwater Research. 53 (2): 531–541. doi:10.1071/MF01074. Archived from the original (PDF) on 2017-08-11. Retrieved 2010-04-08.
  18. ↑ Rosenberger, L.J. (2001). "Pectoral fin locomotion in batoid fishes: undulation versus oscillation" (PDF). The Journal of Experimental Biology. 204 (2): 379–394. doi:10.1242/jeb.204.2.379. PMID   11136623.
  19. 1 2 Jordan, L.K (2008). "Comparative Morphology of Stingray Lateral Line Canal and Electrosensory Systems". Journal of Morphology. 269 (11): 1325–1339. doi:10.1002/jmor.10660. PMID   18655157. S2CID   33886896. Archived from the original on 2013-01-05.
  20. ↑ Jordan, L.K.; S.M. Kajiura & M.S. Gordon (2009). "Functional consequences of structural differences in stingray sensory systems. Part I: mechanosensory lateral line canals" (PDF). Journal of Experimental Biology. 212 (19): 3037–3043. doi: 10.1242/jeb.028712 . PMID   19749095.
  21. ↑ Jordan, L.K.; S.M. Kajiura & M.S. Gordon (2009). "Functional consequences of structural differences in stingray sensory systems. Part II: electrosensory system" (PDF). Journal of Experimental Biology. 212 (19): 3044–3050. doi: 10.1242/jeb.028738 . PMID   19749096.
  22. 1 2 3 Véras, D.P.; T. Vaske (Jr.); F.H.V. Hazin; R.P. Lessa; P.E. Travassos; M.T. Tolotti & T.M. Barbosa (2009). "Stomach contents of the pelagic stingray (Pteroplatytrygon violacea) (Elasmobranchii: Dasyatidae) from the tropical Atlantic". Brazilian Journal of Oceanography. 57 (4): 339–343. doi: 10.1590/S1679-87592009000400008 .
  23. ↑ Ribeiro-Prado, C.C. & A.F. de Amorim (2008). "Fishery biology on pelagic stingray Pteroplatytrygon violacea caught off southern Brazil by longliners settled in Sao Paulo state (2006–2007)" (PDF). International Commission for the Conservation of Atlantic Tunas Collective Volume of Scientific Papers. 62: 1883–1891. Archived from the original (PDF) on 2012-02-25. Retrieved 2010-04-08.
  24. 1 2 3 4 5 Wilson, P.C. & J.S. Beckett (December 12, 1970). "Atlantic Ocean Distribution of the Pelagic Stingray, Dasyatis violacea". Copeia. American Society of Ichthyologists and Herpetologists. 1970 (4): 696–707. doi:10.2307/1442312. JSTOR   1442312.
  25. ↑ Baer, J.G. (1948). "Contributions a l'etude das cestodes de selachians IIV". Bulletin de la Société des Sciences Naturelles de Neuchâtel. 71: 63–122.
  26. ↑ Euzet, L. (1959). Recherches sur les cestodes tetraphyllides des selacaens des cotes de France. Thesis, Montpellier.
  27. ↑ Euzet, L. & C. Combes (1965). "Contribution a l'etude de Tetragonocephalum uarnak (Shipley et Hornell, 1906)". Bulletin de la Société des Sciences Naturelles de Neuchâtel. 88: 101–122.
  28. ↑ Llewellyn, J. & L. Euzet (1964). "Spermatophores in monogenean Entobdella diadema Monticelli from skin of sting-rays with a note on the taxonomy of the parasite". Parasitology. 54 (2): 337–344. doi:10.1017/S0031182000067962. S2CID   84808479.
  29. ↑ Forselledo, R.; M. Pons; P. Miller & A. Domingo (2008). "Distribution and population structure of the pelagic stingray, Pteroplatytrygon violacea (Dasyatidae), in the south-western Atlantic". Aquatic Living Resources. 21 (4): 357–363. doi: 10.1051/alr:2008052 .
  30. ↑ Hemida, F.; R. Seridji; S. Ennajar; M.N. Bradai; E. Collier; O. Guelorget & C. Capape (2003). "New observations on the reproductive biology of the pelagic stingray, Dasyatis violacea Bonaparte, 1832 (Chondrichthyes: Dasyatidae) from the Mediterranean Sea". Acta Adriatica. 44 (2): 193–204.
  31. 1 2 Dulvy, N.K.; J.K. Baum; S. Clarke; L.J.V. Compagno; E. Cortes; A. Domingo; S. Fordham; S. Fowler; M.P. Francis; C. Gibson; J. Martinez; J.A. Musick; A. Soldo; J.D. Stevens & S. Valenti (2008). "You can swim but you can't hide: the global status and conservation of oceanic pelagic sharks and rays" (PDF). Aquatic Conservation: Marine and Freshwater Ecosystems. 18 (5): 459–482. doi:10.1002/aqc.975. Archived from the original (PDF) on 2009-09-17.
  32. ↑ Guide of Mediterranean Skates and Rays (Pteroplatytrygon violacea). Oct. 2022. Mendez L., Bacquet A. and F. Briand. http://www.ciesm.org/Guide/skatesandrays/pteroplatytrygon-violacea
  33. ↑ Ward, P. & R.A. Myers (2005). "Shifts in open-ocean fish communities coinciding with the commencement of commercial fishing" (PDF). Ecology. 86 (4): 835–847. doi:10.1890/03-0746. Archived from the original (PDF) on 2007-09-28.
  34. ↑ Duffy, Clinton A. J.; Francis, Malcolm; Dunn, M. R.; Finucci, Brit; Ford, Richard; Hitchmough, Rod; Rolfe, Jeremy (2018). Conservation status of New Zealand chondrichthyans (chimaeras, sharks and rays), 2016 (PDF). Wellington, New Zealand: Department of Conservation. p. 11. ISBN   9781988514628. OCLC   1042901090.
  35. ↑ Piovano, S.; S. Clò & C. Giacoma (2010). "Reducing longline bycatch: The larger the hook, the fewer the stingrays". Biological Conservation. 143: 261–264. doi:10.1016/j.biocon.2009.10.001.

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