The main predators of stingrays are humans. Another predator of southern stingrays are great hammerhead sharks (Sphyrna mokarra). The shape of this shark’s head enables it to hold down stingrays while feeding on them. Stingrays will often bury themselves in the sand to avoid detection by predators, and will also use their venomous tail spine in self defense.
Known Predators:
Anti-predator Adaptations: cryptic
This species is an elasmobranch (a cartilaginous fish) in the superorder Batoidea. Batoid species have a broad, flat, disc-shaped body that is formed by the fusion of the dorsoventrally flattened body, pectoral fins, and the head. In southern stingrays, the body and pectoral fins are expanded to form a diamond-shaped disc, which is about 1.2 times as broad as it is long, with females generally being larger than males. The disc width of Southern stingrays raised in captivity ranges from 48 to 53cm in males and 75 to 80cm for females. In captivity, the maximum reported disc width for male is 80cm and for female is 150cm. Wild southern stingrays have reached a maximum disc width of 200cm and a weight of 97kg. The tail can be up to twice as long as the body, and carries a sharp, serrated, venomous spine that is used in defense. The gills are located on the underside of the body. The eyes are located on top of the head, which is elevated above the rest of the body. Due to its feeding habits and elevated head, southern stingrays have spiracles that enable them to take in water dorsally. The skin is covered with denticles, which are scale-like body coverings. Body coloration ranges between dark gray, green, and brown.
Range mass: 87.7 (high) kg.
Range length: 150 (high) cm.
Average length: 75-80 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry ; venomous
Sexual Dimorphism: female larger
Very little is known about the average lifespan of this species. In a single study, the oldest age recorded for males was 12 years. The oldest recorded female was estimated to be 13 years old.
Range lifespan
Status: wild: 12 to 13 years.
Southern stingrays are a marine species and are generally found in shallow waters (about 2 meters deep) of bays filled with sea grass beds and algal fields.
Range depth: 0 to 53 m.
Habitat Regions: temperate ; tropical ; saltwater or marine
Aquatic Biomes: benthic ; reef ; coastal
Southern stingrays are found in the the western Atlantic Ocean from New England to Brazil, with abundant populations in the Caribbean Sea, Gulf of Mexico, Grand Cayman Island, British West Indies, Bahamas, coastal Belize, and the southern coast of Florida.
Biogeographic Regions: nearctic (Native ); neotropical (Native ); atlantic ocean (Native )
Southern stingrays feed on multiple organisms throughout the day (more so at night), so they are considered to be continuous foragers and opportunistic feeders. One study found the stomach contents of a southern stingray to include prey from 15 families, in four phyla. Major prey were crustaceans, small fishes, and worms.
Animal Foods: fish; mollusks; aquatic or marine worms; aquatic crustaceans
Primary Diet: carnivore (Piscivore , Eats non-insect arthropods)
Southern stingrays act as predators of several marine fish and invertebrate species, as well as serving as prey to larger cartilaginous fish species (particularly hammerhead sharks). A commensal foraging relationship has been documented between southern stingrays and double-crested cormorants (Phalacrocorax auritus), which are common coastal birds ranging from North Carolina to the Gulf of Mexico. As stingrays excavate the substrate in search of prey, they often stir up fish. The birds dive in and swim behind the stingrays to feed on snappers and grunts, though this is only possible in shallow waters. This stingray foraging habit also attracts follower organisms, which remain near a host in hopes of finding food. Some observed follower organisms of stingrays include Carangoides bartholomaei, Caranx latus, Cephalopholis fulva, Halichoeres radiatus, Halichoeres dimidiatus, Dactylopterus volitans, and Lactophrys trigonus. Bluehead wrasse (Thalassoma bifasciatum) serve as mutualistic cleaner organisms for southern stingrays.
Mutualist Species:
Commensal/Parasitic Species:
In developing countries, southern stingrays are an important food resource. Southern stingrays are also a large tourist attraction in coastal and island locations throughout their range. A popular tourist site for stingray interaction, “Stingray City Sandbar”, is located in the Cayman Islands. About 150 southern stingrays are found there yearly. The stingrays at this location are found during the day and in a very crowded space, where tourists can hand feed them. The venoms found in association with the spines of stingrays are currently being researched for possible applications in biomedical and neurobiological applications.
Positive Impacts: food ; ecotourism ; source of medicine or drug ; research and education
One report speculates that southern stingrays may communicate using pheromones. It was observed that the birth of offspring attracts males, leading scientists to suspect that birth produces some kind of olfactory attractant that alerts neighboring males, perhaps arising from organic molecules produced in the female's cloaca. Since female southern stingrays are able to mate soon after parturition, these could be considered to be sexual pheromones. Males occasionally touch females before, and bite them during mating, which may also serve in some communicative capacity.
Like other elasmobranchs, southern stingrays are equipped with highly developed senses of smell. They also possess thousands of Ampullae of Lorenzini on their undersides, particularly concentrated around the head, which allow them to sense electrical field produced by buried prey. Elasmobranchs also have lateral lines for sensing vibrations in the water, and a well-develped sense of hearing. The eyes of southern stingrays are not likely to be useful in sensing prey, being placed on top of the head. However, they are still rather large and well-developed and are likely used to sense predators and other disturbances in the water above.
Communication Channels: tactile ; chemical
Other Communication Modes: pheromones
Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical ; electric
Because southern stingrays are large elasmobranchs with relatively low reproductive rates and slow growth, they are at risk of overfishing. Currently, this species has no special conservation status. Populations near the United States appear to be healthy, but there is little information on the populations in other areas where fishing pressure is heavier.
Growing tourism also appears to be affecting southern stingray populations. This is illustrated by the case of “Stingray City Bar”. This species is normally active at night and is a solitary forager, but at this site it is found during the day (when tourist activity is high) and in close proximity with conspecifics year-round. The continuous supply of food keeps the stingrays in this area and causes alterations to their behavior. Another issue is the hand feeding of these wild animals with foods such as squid, which are not found in their natural diet. Long term feeding with these abnormal foods can negatively impact southern stingrays by affecting their health and mobility.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Fully-developed young are born soon after hatching from their egg capsules, which occurs inside the mother's body. Hatchlings resemble minature versions of their parents.
Development - Life Cycle: indeterminate growth
Southern stingrays are not known to be aggressive towards humans. Since the they are often found buried in the sand in shallow waters, it is easy to step on them. When stepped on, they will use their venomous spine in self-defense.
Negative Impacts: injures humans (bites or stings, venomous )
Very little is known about the mating systems of southern stingrays. However, one study was able to report observations based on a single female southern stingray mating with two males. The female was followed by the two males, with one male eventually biting and holding onto her pectoral fin. This male then positioned himself so that his pelvic region was curled toward the female’s urogenital opening (also known as the cloaca). The male then flipped upside down and thrust his pelvic region in a rapid sequence for 10 to 33 seconds. Following this, the male released his bite from the female’s pectoral disc. Females are able to mate again soon after giving birth
Mating System: polygynandrous (promiscuous)
Age at sexual maturity varies with the geographical region. In captivity, females were impregnated, and thus considered mature, at about 5 to 6 years. Males, on the other hand, were considered mature at about 3 to 4 years. Maternal size is positively correlated with the number of offspring, which can range from 2 to 10. Stingrays that are raised in captivity bear young biannually, while in wild stingrays, it is usually once a year. Breeding behavior has been observed in early September in the Grand Cayman Islands, and in late August at Bimini, Bahamas. Gestation period ranges from 125 to 226 days with a mean of 175 days.
Southern stingrays use both primary and secondary nurseries for the development of young. The primary nursery is a habitat where a female gives birth to her offspring, while the secondary nursery is habitat where juveniles reach maturity. Little is known about the specific locations of these nurseries and migration of the offspring between the two habitats. In Belize, Glovers Reef is a known primary nursery where adult southern stingrays only visit seasonally for mating or to give birth. Scientists caught juvenile southern stingrays during the months of May, November, and December at a depth of 10 to 20 m on nearby rocky reef surfaces, which is believed to be a secondary nursery.
Breeding interval: Breeding occurs annually in the wild, biannually in captivity.
Breeding season: Breeding occurs in summer to early fall, varying depending on geography.
Range number of offspring: 2 to 10.
Average number of offspring: 4.2.
Range gestation period: 125 to 226 days.
Average gestation period: 175 days.
Range age at sexual or reproductive maturity (female): 5 to 6 years.
Range age at sexual or reproductive maturity (male): 3 to 4 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; induced ovulation ; fertilization (Internal ); ovoviviparous
Southern stingrays are ovoviviparous (producing young by means of eggs that are hatched inside the body of the female), meaning that unborn young are protected by the mother due to developing inside her body. During early development, the embryo uses a yolk sac for its nutrition. After the yolk sac is absorbed, nutrients are provided by the mother through the secretion of histotroph ("uterine milk"). No further parental investment occurs after the young stingrays are born.
Parental Investment: female parental care ; pre-hatching/birth (Provisioning: Female, Protecting: Female)
Der Amerikanische Stechrochen (Hypanus americanus), auch Südlicher Stechrochen genannt, ist eine Stechrochenart und lebt im westlichen Atlantik von nördlich der Küste New Jerseys bis zum südlichen Brasilien, in der Karibik und im nördlichen Golf von Mexiko.
Hypanus americana wird maximal zwei Meter lang, bleibt aber für gewöhnlich bei 90 Zentimeter. Er hat eine rautenförmige Brustflossen-Scheibe die maximal 1,20 Meter breit wird und an den Seiten und der Schnauze nur wenig abgerundet ist. Die Oberseite zeigt kein Muster und ist meist olivbraun, seltener fast schwarz, bei Jungtieren grau. Die Unterseite ist weiß, mit grauem oder braunem Rand. Entlang des Rückens zieht sich eine Reihe spitzer Warzen. Auf dem Schwanz trägt er meist zwei Giftstachel.
Der Rochen lebt küstennah über sandigem Grund und Seegras sowie in Lagunen und Riffen in Tiefen von einem bis 25 Metern. Amerikanische Stechrochen leben einzeln, paarweise oder in Gruppen. Tagsüber liegen sie oft, von einer dünnen Sandschicht bedeckt, inaktiv herum.
Sie ernähren sich von kleinen Knochenfischen, Krusten- und Weichtieren, die sie aktiv erjagen oder aus dem Meeresboden ausgraben. Seinen Giftstachel benutzt der Amerikanische Stechrochen nur zur Verteidigung. Er ist ovovivipar mit Würfen von drei bis fünf Jungtieren, die bei der Geburt etwa 20 Zentimeter lang sind.
Gegenüber Tauchern sind die Tiere wenig scheu. Bei den Cayman-Inseln wurden Amerikanische Stechrochen angefüttert und an Menschen gewöhnt. Dieser als „Stingray City“ bekannte Platz ist ein beliebtes Ziel des Tauchtourismus.
Die Rochenart wurde im Jahr 1928 durch die US-amerikanischen Ichthyologen Samuel Frederick Hildebrand und William C. Schroeder unter der wissenschaftlichen Bezeichnung Dasyatis americana beschrieben. Bei einer Mitte 2016 erfolgten Revision der Dasyatidae wurde die Art in die Gattung Hypanus gestellt.[1]
Der Amerikanische Stechrochen (Hypanus americanus), auch Südlicher Stechrochen genannt, ist eine Stechrochenart und lebt im westlichen Atlantik von nördlich der Küste New Jerseys bis zum südlichen Brasilien, in der Karibik und im nördlichen Golf von Mexiko.
The southern stingray (Hypanus americanus) is a whiptail stingray found in tropical and subtropical waters of the Western Atlantic Ocean from New Jersey to southern Brazil.[2] It has a flat, diamond-shaped disc, with a mud brown, olive, and grey dorsal surface and white underbelly (ventral surface).[3] The barb on its tail is serrated and covered in a venomous mucus, used for self-defense.
The southern stingray is adapted for life on the sea bed. Its flattened, diamond-shaped body is more angular than other rays.[4] The top of the body varies between olive brown and green in adults, dark grey in juveniles, whilst the underside is white.[4][5] The wing-like pectoral fins are used to propel the stingray across the ocean bottom, whilst the slender tail possesses a long, serrated and venomous spine at the base, used for defence.[6] These spines are not fatal to humans, but are incredibly painful if stepped on. The eyes are situated on top of the head of the southern stingray, along with small openings called spiracles. The location of the spiracles enables the stingray to take in water whilst lying on the seabed, or when partially buried in sediment. Water enters the spiracles and leaves through the gill openings, bypassing the mouth which is on the underside.[4][6] Female stingrays can grow to a disc width of 150 centimetres (59 in), while the smaller male stingrays reach a maximum size of 67 centimetres (26 in).[7][8]
Southern stingrays are nocturnal predators, who spray water from their mouths or flap their fins vigorously to disturb the substrate and expose hidden prey. This bottom-dwelling species is often found singly or in pairs, and can reach population densities estimated up to 245 per square kilometre (630/sq mi) in certain shallow systems thought to be nursery grounds.[9] Hypanus americanus exhibit wave-like locomotion using their pectoral fins. This wave-like motion is important for Hypanus americanus because it allows them to escape predators, forage efficiently, and generally maneuver quickly. Typically, they travel large distances and their foraging area is very expansive. One study provided observations that Hypanus americanus swim along the tide, because of the greater food availability along tides. Hypanus americanus are able to do this because of their high maneuverability and efficient wave-like locomotion. Hypanus americanus either remain solitary or form groups. Groups of Hypanus americanus are usually observed when they mate, for predator protection or even when they are just resting.[10][11][12][13][14]
When scientists revealed the contents of the stomach of one Hypanus americanus, they found evidence of a great variety of ingested prey, including small fishes, worms, crustaceans and bivalves.[15] As mentioned earlier in this article, the Hypanus americanus are smooth and efficient swimmers, allowing them to capture a variety of mobile as well as sessile prey. They are opportunistic feeders and continuous foragers.[16]
To avoid predators, Hypanus americanus bury themselves in substrate. Venomous spines on the tail are used to repel predators, including humans and great hammerhead sharks.[17][18]
In shallow waters, there is a commensal foraging relationship between Hypanus americanus fish and Nannopterum auritum birds in coastal areas generally like the Gulf of Mexico. When foraging, the Hypanus americanus dig through the substrate in search of food; however, this also helps to expose certain other fish hidden in the substrate after which the Nannopterum auritum will follow behind the Hypanus americanus and eat.[19][20][21][22][23][24]
Hypanus americanus are ovoviviparous. Fertilized eggs develop inside the mother's body. The embryos receive nutrients from the yolk sack early in development. After the yolk sac is absorbed, the embryos obtain nutrients from the histotroph (the mother's uterine milk). Females reproduce annually. This species gives live birth after a pregnancy which usually lasts between seven to eight months.[25] Parental care ceases once the young are born. In captivity, gestation lasted 135 to 226 days, after which a litter of two to ten young were born.[7]
There is little knowledge or published evidence about the mating systems of Hypanus americanus. Mating stingrays are rarely encountered in the wild. One study, however, does provide detailed observations of Hypanus americanus mating. This study involves observations of one female mating with two males. The study mentions that the female was chased by the two males, with one of the male's biting (or "catching") the female's fin and releasing her after copulation. Females have the ability to mate again soon after giving birth.[26]
Geographical location plays a large role in the age of sexual maturity. Observations from studies of breeding behavior (of Hypanus americanus during August at Bimini, Bahamas, and early September in Grand Cayman, Cayman Islands). One study shows that when females were placed in captivity, they were considered mature when they were impregnated (around 5 or 6 years old). In this case, males who were 3 or 4 years old were considered to be mature. There is also a difference in the rate at which the females bear young, depending on whether they are raised in captive natural environments or in natural environments. Females raised in captivity bear offspring twice a year, and females that are raised in the wild bear offspring once a year. In addition, there is a positive correlation between the size of the mother and the number of offspring.[26] There is a difference in nurseries for where the Hypanus americanus offspring are raised: there are primary and secondary nurseries which have a clear distinction. The primary nursery is defined as a habitat where a female Hypanus americanus gives birth to her young. On the other hand, the secondary nursery is a habitat where the juvenile Hypanus americanus are raised to mature adults. Little evidence about locations of and migrations between the primary and secondary nurseries is known. An example of a primary nursery is in Belize, where Hypanus americanus females pay seasonal visits for the purposes of mating and giving birth to offspring. During one study, juvenile Hypanus americanus were caught by scientists at 10 to 20 m depths on rock reef surfaces nearby during the months of May, November and December. This specific location of where these juvenile Hypanus americanus were collected was believed to be a secondary nursery.[7][27]
Studies of Hypanus americanus have shown that they communicate through pheromone signaling. Males communicate with females before copulating by touching and biting the females. Also, after the female gives birth, she releases pheromones that are most likely believed to be produced in her cloaca; one study reported that the birth of offspring attracted males. As previously mentioned in the article, since a female has the ability to mate soon after giving birth, it is plausible that these are sex pheromones. The role of pheromones in communication also make sense since Hypanus americanus have strong senses of smell. They have many Ampullae of Lorenzini, usually heavily concentrated around the head. In addition, this gives them the ability to sense certain electric fields which are emitted from hidden prey. In addition, they have special mechanisms for senses vibrations in the water as well as for hearing.[26][28]
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In many parts of the Caribbean such as Grand Cayman, Cayman Islands and Antigua, the southern stingray swims with divers and snorkelers, and are hand fed at locations such as Stingray City and the Sandbar.[13] On Turks & Caicos, they can be hand fed at a location called Gibbs Cay. Some have become tame enough to be cradled in visitors' arms and feed with pieces of cut up fish. This docile and food-reward driven behaviour has led to many locals comparing the hand-fed and belly-rubbed stingray to an over-fed household canine. There are concerns that this feeding, and the high levels of interaction with humans, may be having some negative impacts on their behaviour and ecology.[29]
The southern stingray may make its way into the aquarium trade. Despite its relative hardiness, it is best avoided as it requires an immense 4,200 gallon capacity system and will devour any fish or invertebrate it is able to capture.[30] They are also housed within public aquariums and animal theme parks including Six Flags Discovery Kingdom in Vallejo, California and the Long Island Aquarium in Riverhead, New York where visitors are allowed to pet the rays in a touch pool.[31][32] In public aquariums, female southern stingrays have been seen biting one another on the edges of their fins. Reproduction has also been known to occur within large public aquariums.[30]
A southern stingray in Bonaire.
Several southern stingrays swimming around at Grand Cayman.
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A southern stingray in resting under a layer of sand in Costa Rica.
A southern stingray at the Georgia Aquarium in Atlanta, Georgia.
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A southern stingray resting near rock outcrops at San Salvador Island.
A southern stingray accompanied by a rainbow runner (Elagatis bipinnulata) in Anegada.
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A southern stingray swimming over a meadow of turtle grass (Thalassia testudinum) at Caye Caulker in Belize.
The underside of a southern stingray along with a few yellowtail snapper (Ocyurus chrysurus).
This article incorporates text from the ARKive fact-file "Southern stingray" under the Creative Commons Attribution-ShareAlike 3.0 Unported License and the GFDL.
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{{cite journal}}: CS1 maint: multiple names: authors list (link) Wikimedia Commons has media related to Hypanus americanus. The southern stingray (Hypanus americanus) is a whiptail stingray found in tropical and subtropical waters of the Western Atlantic Ocean from New Jersey to southern Brazil. It has a flat, diamond-shaped disc, with a mud brown, olive, and grey dorsal surface and white underbelly (ventral surface). The barb on its tail is serrated and covered in a venomous mucus, used for self-defense.
La raya de espina o raya-látigo americana (Hypanus americanus) es una especie de elasmobranquio rajiforme de la familia Dasyatidae propia de los mares tropicales y subtropicales del Océano Atlántico meridional, el mar Caribe y el Golfo de México. Tiene un cuerpo plano, de forma diamantada, con un color marrón fango en la parte superior y blanco en el vientre. La lengüeta en su cola es venenosa y la utiliza para la autodefensa.
Es una especie que tolera amplios intervalos de temperatura y de salinidad. Se alimenta de grandes invertebrados así como de pequeños peces bentónicos, lo cual hace principalmente de noche, mientras que durante el día permanece casi completamente enterrada en el sustrato arenoso, aunque también se la puede encontrar en fondos fangosos.
En muchas partes del Caribe, como las islas Caimán y la isla de Antigua, pueden verse nadar con los buzos y nadadores que se le acerquen, e incluso son alimentadas a mano (normalmente con sobras de pescado) en algunas localidades. Algunas se han hecho lo suficientemente mansas para acurrucarse en los brazos.
El embarazo dura cinco meses en esta especie, aunque incluso puede llegar a durar hasta nueve, y tienen por lo general de tres a cinco crías por camada.
La raya de espina o raya-látigo americana (Hypanus americanus) es una especie de elasmobranquio rajiforme de la familia Dasyatidae propia de los mares tropicales y subtropicales del Océano Atlántico meridional, el mar Caribe y el Golfo de México. Tiene un cuerpo plano, de forma diamantada, con un color marrón fango en la parte superior y blanco en el vientre. La lengüeta en su cola es venenosa y la utiliza para la autodefensa.
Dasyatis americana Dasyatis generoko animalia da. Arrainen barruko Dasyatidae familian sailkatzen da.
Dasyatis americana Dasyatis generoko animalia da. Arrainen barruko Dasyatidae familian sailkatzen da.
Raie pastenague américaine
Dasyatis americana, communément nommée Raie pastenague américaine[2], est une espèce de poissons marins de la famille des Dasyatidae.
La Raie pastenague américaine est présente dans les eaux tropicales de l'océan Atlantique occidental, soit des côtes de l'état du New Jersey aux côtes orientales du Brésil incluant le golfe du Mexique ainsi que la mer des Caraïbes[1].
Le diamètre maximal de son disque est de 150 cm mais le diamètre moyen observable est 80 cm[3].
Raie pastenague américaine
Dasyatis americana, communément nommée Raie pastenague américaine, est une espèce de poissons marins de la famille des Dasyatidae.
La Raie pastenague américaine est présente dans les eaux tropicales de l'océan Atlantique occidental, soit des côtes de l'état du New Jersey aux côtes orientales du Brésil incluant le golfe du Mexique ainsi que la mer des Caraïbes.
Le diamètre maximal de son disque est de 150 cm mais le diamètre moyen observable est 80 cm.
La pastinaca americana (Dasyatis americana) è un pesce cartilagineo della famiglia Dasyatidae, distribuito nelle acque tropicali e subtropicali dell'oceano Atlantico occidentale, dalle coste del New Jersey al Brasile. Nota anche come trigone meridionale o trigone atlantico, vive in prevalenza in fondali sabbiosi, in lagune e intorno alle distese di alghe non oltre i 25-30 metri di profondità.
La pastinaca americana è una razza caratterizzata da un corpo grande e robusto: la lunghezza oscilla tra i 150 e i 190 cm . Il dorso è di color grigio-brunastro scuro uniforme, mentre il ventre è bianco. La lunga coda è dotata di un robusto aculeo seghettato in prossimità del corpo. Il dorso è percorso da una fila di tubercoli spinosi. Gli occhi sporgenti sono dotati di una pupilla protetta da un lembo cutaneo utile alla mimetizzazione e alla regolazione della quantità di luce disponibile.
Dietro la cavità orbitale è evidente uno spiracolo, spesso l'unico elemento visibile sporgente dalla sabbia.
È una specie intelligente, dall'indole timida ma curiosa, in grado di infliggere gravi danni con il lungo aculeo caudale se molestata. Sono alcuni i casi mortali attribuiti a questa pastinaca di grosse dimensioni. Animale prevalentemente notturno, trascorre il giorno nascosto sotto la sabbia. Si nutre di invertebrati come granchi, gamberi, vermi e piccoli pesci bentonici. Dà alla luce dai tre ai cinque piccoli, nati per cucciolata solitamente dopo 5 mesi di gravidanza (che in alcuni casi può durare fino a 9 mesi).
La pastinaca americana (Dasyatis americana) è un pesce cartilagineo della famiglia Dasyatidae, distribuito nelle acque tropicali e subtropicali dell'oceano Atlantico occidentale, dalle coste del New Jersey al Brasile. Nota anche come trigone meridionale o trigone atlantico, vive in prevalenza in fondali sabbiosi, in lagune e intorno alle distese di alghe non oltre i 25-30 metri di profondità.
