Although roughtail stingrays are not considered threatened, their large size and low fecundity make them vulnerable to population decreases. They are sometimes taken as bycatch or are accidentally caught through trawl fishing, artisanal fisheries and other fishing practices.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Sharks are the main predators of stingrays, including rougtail stingrays. To avoid visual detection, rays conceal themselves just below the surface of muddy and sandy bottoms. Their barbed spine serves as a defense against certain predators; however, it is not always successful, as stingray spines are found in the mouths of many types of sharks. Great hammerhead sharks have a unique method of eating rays: they pin down a ray to the seafloor using their uniquely shaped head, then pivot around to bite the ray's disc. Some humans also eat roughtail stingrays.
Known Predators:
Anti-predator Adaptations: cryptic
Male roughtail stingrays have an average width of 1.5 m while females have an average width of 1.6 m. Their disc length can be as long as 2.2 m. The body of roughtail stingrays is diamond-shaped, and a long tail trails from their backside. Their whiplike tail has many rows of venomous barbs and can grow up to 2.5 times the length of the body. Body color ranges from dark brown to an olive tone. The underside is white, while the tail is black. The outer edges of their disc bear distinctive conical tubercles. Roughtail stingrays do not have a dorsal finfold, and their snout is fairly long and angular. They can weigh as much as 300 kg.
Range mass: 300 (high) kg.
Range length: 221 (high) cm.
Other Physical Features: ectothermic ; bilateral symmetry ; venomous
Sexual Dimorphism: female larger
Little information is known regarding the lifespan and longevity of roughtail stingrays. Some sharks and rays do not reach full maturity for 20 to 30 years. Large rays live about 70 years, some living for more than 100 years.
Roughtail stingrays usually reside in benthic environments and in marine and brackish waters. They prefer areas with sandy bottoms. In the summer, they favor bays, estuaries, and coastal waters, and in winter, they move away from the coast but not beyond the continental shelf. They generally swim at depths of 50 to 200 m, but they have been seen at depths of 274 m in the Bahamas. In the eastern Atlantic Ocean, roughtail stingrays remain near shore and are found at an average depth of 60 m, while rays in the western Atlantic are found deeper at 200 m.
Range depth: 50 to 274 m.
Habitat Regions: tropical ; saltwater or marine
Aquatic Biomes: benthic ; coastal ; brackish water
Other Habitat Features: estuarine
Roughtail stingrays, Dasyatis centroura, reside in tropical and temperate waters of the coastal Atlantic Ocean, ranging from the coast of Massachusetts to Brazil, the Mediterranean Sea, the Bay of Biscay, and Angola. During summer months, roughtail stingrays are more prevalent in bays, estuaries and coastal waters. From December to May, they tend to migrate to northern waters away from the coast but not beyond the continental shelf.
Biogeographic Regions: nearctic (Native ); palearctic (Native ); ethiopian (Native ); neotropical (Native ); atlantic ocean (Native ); mediterranean sea (Native )
Roughtail stingrays are opportunistic carnivores, adapting their diet to include the most available prey. Crustaceans, such as vernal crabs Liocarcinus vernalis and callianassid shrimp Upogebia affinis, are an integral part of their diet. Stomach content analyses indicate that roughtail stingrays eat cephalopods such as squid Loligo and cuttlefish Sepia latimanus. Other prey include bony fishes, like sand lance Ammodytes dubius and scup Stenotomus chrysops. Infaunal polychaete worms (Glycera dibranchiata) are also consumed.
Animal Foods: fish; mollusks; aquatic or marine worms; aquatic crustaceans; cnidarians
Primary Diet: carnivore (Piscivore , Eats non-insect arthropods)
Rays, such as roughtail stingrays, are avid hunters of benthic mollusks, fish, crustaceans and worms, and they may help regulate infaunal benthic community structure. Rays are also prey for sharks, such as great hammerhead sharks.
Roughtail stingrays are commonly eaten by Australian Aborigines. The Aborigines use stingray spines to make spears tips, daggers, and whips. Rays are also consumed in Europe and Asia, and the fins of some rays are harvested in Asia for traditional medicinal purposes.
Positive Impacts: food ; source of medicine or drug
Roughtail stingrays have an excruciating venomous sting, which serves as their primary defense if stepped on or threatened. In some cases, their sting has been fatal to humans. Although rays are more commonly found in water depths of 50 to 200 m, they occasionally travel to shallower waters, posing a threat to humans.
Negative Impacts: injures humans (bites or stings, venomous )
Rays in the family Dasyatidae, including roughtail stingrays, produce relatively few young. Stingrays in general have 1 litter a year, producing between 2 and 6 young. Embryos developing in their mother's womb receive most of their nutriment from the histotroph, a milky substance secreted by the mother’s uterine lining. Embryos absorb nutriment through their skin and spiracles. During this time, embryos absorb the yolk sack and stalk. Roughtail stingrays are born fully developed and relatively large (up to half the size of a full grown adult), increasing their chances of survival.
Roughtail stingrays use touch, taste, sight, hearing, and smell to perceive their enviornment. Furthermore, like other cartilaginous fish, they can detect electical waves produced by other organisms. They use this ability to find infaunal prey buried within the substrate.
Communication Channels: tactile ; chemical
Other Communication Modes: vibrations
Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical ; electric ; magnetic
Little is known about the natural mating behavior and mating system of roughtail stingrays. They, like other stingrays, do not form monogamous pairs, and they may be polygynous like southern sting rays (Dasyatis americana). Rays practice internal fertilization; a male inserts one of his two claspers into the female’s cloaca to deposit sperm.
Male roughtail stingrays reach sexual maturity at a length of 130 to 150 cm and females at 140 to 160 cm. In females ready to reproduce, their left ovary is commonly more developed than the right. Roughtail stingrays generally breed in Autumn or early winter. Gestation lasts 4 months, and females usually give birth in April. Stingrays have one litter a year, producing between 2 and 6 young. Roughtail stingrays measure between 34 at 37 cm at birth.
Breeding interval: Roughtail Stingrays breed once a year.
Breeding season: Roughtail Stingrays breed in Autumn or early winter.
Range number of offspring: 2 to 6.
Average gestation period: 4 months.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; induced ovulation ; fertilization (Internal ); ovoviviparous
Pregnant female roughtail stingrays provide nutritional support to their developing offspring. While young are in the embryonic sac, their stomachs and intestine develop first. This helps them to digest the milky fluid (histotroph) secreted by their mother's uterus. After birth, young rays receive no further investment from their mother and are able to find food on their own.
Parental Investment: no parental involvement; pre-hatching/birth (Provisioning: Female, Protecting: Female)
The roughtail stingray (Bathytoshia centroura) is a species of stingray in the family Dasyatidae, with separate populations in coastal waters of the northwestern, eastern, 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,[2] 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.
Often found lying on the bottom buried in sediment, the roughtail stingray is a generalist predator that feeds on a variety of benthic invertebrates and bony fishes. It is aplacental viviparous, with the embryos receiving nourishment initially from yolk, and later from histotroph ("uterine milk") produced by the mother. In the northwestern Atlantic, females bear an annual litter of 4–6 young in fall and early winter, after a gestation period of 9–11 months. By contrast, in the Mediterranean there is evidence that females bear two litters of 2–6 young per year after a gestation period of only four months. Rays in the northwestern Atlantic are also larger at birth and at sexual maturity than those from the Mediterranean. The venomous tail spine of the roughtail stingray is potentially dangerous to humans. The International Union for Conservation of Nature (IUCN) has listed this species as vulnerable overall.
The first description of the roughtail stingray was published by American naturalist Samuel Mitchell in one of the earliest North American works on ichthyology, a short treatise on the fishes of New York in the 1815 first volume of Transactions of the Literary and Philosophical Society of New York.[3][4] Mitchell based his account on specimens caught off Long Island, though did not designate any types, and named the new species Raja centroura, from the Greek centoro ("pricker") in reference to its thorns. Subsequent authors moved this species to the genus Dasyatis.[2][5] This ray may also be referred to as rough-tailed stingray, rough-tailed northern stingray, or thorny stingray.[6][7]
The taxonomy of the roughtail stingray is not fully resolved, with the disjunct northwestern Atlantic, southwestern Atlantic, and eastern Atlantic populations differing in life history and perhaps representing a complex of different species.[1] Lisa Rosenberger's 2001 phylogenetic analysis of 14 Dasyatis species, based on morphology, found that the roughtail stingray is the sister species to the broad stingray (D. lata), and that they form a clade with the southern stingray (D. americana) and the longtail stingray (D. longa).[8] The close relationship between the roughtail and southern stingrays was upheld by a genetic analysis published by Leticia de Almeida Leao Vaz and colleagues in 2006.[9] The roughtail and broad stingrays are found in the Atlantic and Pacific Oceans respectively, and therefore likely diverged before or with the formation of the Isthmus of Panama (c. 3 Ma).[8]
The roughtail stingray is broadly but discontinuously distributed in the coastal waters of the Atlantic Ocean. In the western Atlantic, it occurs from the Georges Bank off New England southward to Florida, the Bahamas, and the northeastern Gulf of Mexico; there are also scattered reports from Venezuela to Argentina and on the Barrier reef in Belize. In the eastern Atlantic, it occurs from the southern Bay of Biscay to Angola, including the Mediterranean Sea, Madeira, and the Canary Islands. A single record from Kollam, India was likely a misidentification.[1]
One of the deepest-diving stingrays, the roughtail stingray has been recorded to a depth of 274 m (899 ft) in the Bahamas and regularly occurs down to 200 m (660 ft) in the Mediterranean.[7] However, it is most common at a depth of 15–50 m (49–164 ft).[6] This bottom-dwelling species favors live-bottom habitat (patches of rough terrain that are densely encrusted by sessile invertebrates), and also frequents adjacent open areas of sand or mud.[7] Rays in the northwestern Atlantic do not usually enter brackish water, whereas those off West Africa have been recorded from the lower reaches of large rivers.[10][11]
The favored temperature range of the roughtail stingray is 15–22 °C (59–72 °F), which is the most important factor determining its distribution. It conducts seasonal migrations off the eastern United States: from December to May, this ray is found over the middle and outer parts of the continental shelf from Cape Hatteras in North Carolina to Florida, with larger rays occurring further south than smaller ones. In the spring, the population moves north of the Cape and towards the coast into bays, inlets, and saltier estuaries, though preserving the north-south gradient of body sizes. A similar migration, from shallow coastal waters in summer to deeper offshore waters in winter, apparently occurs in the Mediterranean.[7] Pregnant females tend to be found apart from other individuals.[7][12]
The roughtail stingray has a diamond-shaped pectoral fin disk 1.2–1.3 times as wide as long, with straight to gently sinuous margins, rather angular outer corners, and a moderately long, obtuse snout. The eyes are proportionally smaller than other stingrays in its range and immediately followed by larger spiracles. There is a curtain of skin between the nostrils with a finely fringed posterior margin. The mouth is bow-shaped with a row of six papillae (nipple-like structures) across the floor. The seven upper and 12–14 lower tooth rows at the center are functional, though the total number of tooth rows is much greater. The teeth are arranged with a quincunx pattern into flattened surfaces; each has a tetragonal base with a blunt crown in juveniles and females, and a pointed cusp in adult males.[10][13]
The pelvic fins have nearly straight margins and angular tips. The tail is long and whip-like, measuring some 2.5 times the length of the disc. A long, saw-toothed spine is placed atop the tail at around half a disc length back from the tail base; sometimes one or two replacement spines are also present in front of the existing one. Behind the spine, there is a long ventral fin fold that is much lower than that of the southern stingray. Individuals under 46–48 cm (18–19 in) across have completely smooth skin. Larger rays develop increasing numbers of distinctive tubercles or bucklers (flat-based thorns) over the middle of the back from the snout to the tail base, as well as dorsal and lateral rows of thorns on the tail. The bucklers vary in size, with the largest of equal diameter to the eye, and may bear up to three thorns each. This species is a uniform dark brown or olive above, and off-white below without dark fin margins.[10][13] Among the largest members of its family, the roughtail stingray can reach 2.6 m (8.5 ft) across, 4.3 m (14 ft) long, and 360 kg (800 lb) in weight.[14][15] Females grow larger than males.[12]
The roughtail stingray is reportedly not highly active, spending much time buried in the sediment. It is a generalist predator whose diet generally reflects the most available prey in its environment.[7] It mainly captures prey off the bottom, but also opportunistically takes free-swimming prey.[16] A variety of invertebrates, as well as bony fishes such as sand lance and scup, are known to be consumed.[2][7] Off Massachusetts, the main prey are crabs (Cancer), bivalves (Mya), gastropods (Polinices), squid (Loligo) and annelid worms.[10] In Delaware Bay, most of its diet consists of the shrimp Cragon septemspinosa and the blood worm Glycera dibranchiata; the overall dietary composition there is nearly identical to that of bluntnose stingrays (D. say) that share the bay.[16] The shrimp Upogebia affinis is a major food source off Virginia.[1] Off Florida, crustaceans (Rananoides, Ovalipes, Sicyonia brevirostris, and Portunus) and polychaete worms are the most important prey.[7]
Sharks and other large fishes, in particular the great hammerhead (Sphyrna mokarran), prey upon the roughtail stingray.[2] The live sharksucker (Echeneis naucrates) is sometimes found attached to its body.[17] Known parasites of this species include the tapeworms Acanthobothrium woodsholei,[18] Anthocephalum centrurum,[19] Lecanicephalum sp.,[20] Oncomegas wageneri,[21] Polypocephalus sp.,[20] Pterobothrium senegalense,[22] and Rhinebothrium maccallumi,[23] the monogenean Dendromonocotyle centrourae,[24] and the leech Branchellion torpedinis.[25]
Like other stingrays, the roughtail stingray is aplacental viviparous: the developing embryo is initially sustained by yolk and later by histotroph ("uterine milk", containing proteins, lipids, and mucus) delivered by the mother through finger-like projections of the uterine epithelium called "trophonemata". Only the left ovary and uterus are functional in adult females. Off the eastern United States, reproduction occurs on an annual cycle with mating in winter and early spring. After a gestation period of 9–11 months, females give birth to 4–6 (typically five) young in fall or early winter. The newborns measure 34–37 cm (13–15 in) across.[7] Off North Africa, birthing occurs in June and December, indicating either that females bear two litters per year with a four-month gestation period, or that there are two cohorts of females bearing one litter per year with a ten-month gestation period. The newborns are much smaller than those in the northwestern Atlantic at 8–13 cm (3.1–5.1 in) across, which would be consistent with a shorter gestation period.[12] The size at maturity also differs between the two regions: off the eastern United States males and females mature at 130–150 cm (51–59 in) and 140–160 cm (55–63 in) across respectively, while off North Africa males and females mature at 80 cm (31 in) and 66–100 cm (26–39 in) across respectively.[7][12]
With its large size and long, venomous spine, the roughtail stingray can inflict a severe wound and can be very dangerous for fishers to handle. However, it is not aggressive and usually occurs too deep to be encountered by beachgoers.[10] It has been reported to damage farmed shellfish beds. The pectoral fins or "wings" are sold for human consumption fresh, smoked, or dried and salted; the rest of the ray may also be processed to obtain fishmeal and liver oil.[6] The International Union for Conservation of Nature (IUCN) has assessed the roughtail stingray as of Least Concern worldwide, while noting that as a large, slow-reproducing species it is susceptible to population depletion.[1]
In the northwestern Atlantic, the roughtail stingray is listed under Least Concern; it is not targeted or utilized by commercial fisheries, though inconsequential numbers are captured incidentally in trawls and on demersal longlines.[1] Historically, it was sometimes ground up for fertilizer.[10] In the Mediterranean, intensive fishing occurs in the habitat of the roughtail stingray, and it is caught incidentally by artisanal and commercial fishers using trawls, longlines, gillnets, and handlines. Though no specific data is available on this species, declines of other species and its intrinsic susceptibility to depletion have led it to be assessed as Near Threatened in the region. In the southwestern Atlantic, the roughtail stingray and other large rays are heavily fished using demersal trawls, gillnets, longlines, and hook-and-line; this fishing pressure is liable to increase due to growing commercial interest in using large stingrays for minced fish products. Anecdotal reports suggest that landings of this species are decreasing, leading to an assessment of Vulnerable.[1]
The roughtail stingray (Bathytoshia centroura) is a species of stingray in the family Dasyatidae, with separate populations in coastal waters of the northwestern, eastern, 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.
Often found lying on the bottom buried in sediment, the roughtail stingray is a generalist predator that feeds on a variety of benthic invertebrates and bony fishes. It is aplacental viviparous, with the embryos receiving nourishment initially from yolk, and later from histotroph ("uterine milk") produced by the mother. In the northwestern Atlantic, females bear an annual litter of 4–6 young in fall and early winter, after a gestation period of 9–11 months. By contrast, in the Mediterranean there is evidence that females bear two litters of 2–6 young per year after a gestation period of only four months. Rays in the northwestern Atlantic are also larger at birth and at sexual maturity than those from the Mediterranean. The venomous tail spine of the roughtail stingray is potentially dangerous to humans. The International Union for Conservation of Nature (IUCN) has listed this species as vulnerable overall.
