Stingray Anatomy, Diet, and Defense
Uncover the secrets beneath the sand — how stingrays live, hunt, and protect themselves.
Habitat and Daily Life
Stingrays are a group of fish in the suborder of Myliobatoidei [1], inhabiting a wide range of environments from shallow coastal waters to deep-sea trenches more than 3,000 meters below the surface [2]. Most are “benthic”, meaning they spend the majority of their lives on or near the ocean floor. Common habitats include sandy bays, coral reefs, estuaries, and seagrass beds, though some species, like the river stingrays, are fully adapted to freshwater environments in South America [3].
Stingray behavior varies, but some stingrays bury themselves in sand or mud to avoid predators, or to surprise their prey [4]. Their flat shape and the placement of their eyes on top of their bodies allow them to stay camouflaged while keeping a lookout [1]. This stealthy behavior is why the "stingray shuffle" – shuffling one's feet along the ocean floor – is sometimes recommended to avoid stepping on a hidden ray. The idea is that by shuffling your feet, you’re more likely to bump into the side of a stingray, and give it a chance to swim away, rather than accidentally pinning it down with your foot and causing it to sting you.
Daily life for stingrays involves foraging for food, avoiding predators, and occasionally gathering at cleaning stations or during mating seasons [5]. Their movement is usually calm and deliberate, using either oscillatory (wing-like) or undulatory (wave-like) motions to efficiently glide just above the seafloor [6].
Anatomy: Built for the Bottom
Stingrays are cartilaginous fish, meaning their skeletons are made of cartilage rather than bone. This lightweight, flexible material enhances their mobility and allows for their signature flattened body shape, formed by wide pectoral fins fused to their head [7].
The stingray mouth is located on the underside of the body, hidden from view when seen from above. Even though they have cartilage in place of bones, their teeth are adapted for bottom-feeding, with flat, plate-like dental structures designed to crush hard-shelled prey [8]. Along with other adaptations, this makes them strong enough to crush mollusks and crustaceans [1].
For respiration, stingrays use small openings just behind their eyes (called “spiracles”) that draw water into the gills. Like other cartilaginous fish, stingrays don’t have a swim bladder and don’t “float” in the water unless they’re moving. They rely on their large pectoral fins for buoyancy and maneuverability. Their cloaca handles both reproduction and excretion [9].
Senses: More Than Meets the Eye
It is still somewhat unknown how good stingray vision is. Early researchers concluded that sharks and rays had poor vision, just suitable for low light and not able to see color. However, this was largely because the exact species they studied were ‘unlucky’ – they happened to look at the species with the worst vision. More recent research suggests that batoids (which include stingrays) likely have the capability for color vision, and behavioral testing on shovelnose rays shows that they do have color vision [10].
Because their eyes are positioned on top of the body, stingrays do not rely heavily on vision to locate food. Instead, they use electroreception: special sensory pores called ampullae of Lorenzini located near the mouth detect the faint electric fields emitted by prey [1]. This gives them a near sixth-sense advantage when hunting in murky environments.
In addition to using electroreception to sense their prey, scientists suspect that stingrays use magnetoreception – the ability to detect Earth’s magnetic fields – for navigation, especially during migrations or when orienting in complex marine habitats. A recent study showed that yellow stingrays can sense and respond to geomagnetic fields, lending more weight to this suspicion [11].
Their skin is covered in dermal denticles – tiny, tooth-like scales that reduce drag and offer protection. In some freshwater species, females exhibit thicker skin for added protection during mating [9].
Let’s get to the Point: The Barb
Perhaps the most feared feature of the stingray is its tail-mounted stingray barb. This structure is a modified dermal denticle – essentially a serrated, keratinous spine – often coated in venomous mucus. Located near the base or midsection of the stingray tail (depending on the species). Their barbs are regrown periodically, and depending on the season some rays can temporarily possess two barbs at the same time [12]. You can read more about stingray barbs here.
So how do stingrays sting? When a stingray feels threatened (often when stepped on by an unsuspecting beachgoer) stingrays reflexively whip their tail forward in a powerful motion, driving the barb into the perceived threat [13]. The action is fast and forceful, and the serrated spine can embed deeply into tissue. Upon impact, the venomous sheath surrounding the barb tears, delivering stingray venom into the wound [14].
Stingray venom is heat-labile, meaning it breaks down under heat [14]. This is why the standard first aid treatment for a stingray injury is soaking the affected area in hot water (104–113°F) – this helps denature the venom and reduce pain.
Are Stingrays Dangerous?
Despite their fearsome reputation, stingrays are not aggressive. Most injuries occur when someone accidentally steps on a ray resting on the seafloor. People often ask “can a stingray kill you?”, thinking of high-profile incidents like the death of Steve Irwin, who was struck in the chest by a stingray barb. While such fatalities are possible, they are extremely rare [15]. They do however highlight the importance of caution when interacting with stingrays, or any wild animal.
For most people, a stingray sting results in intense localized pain, swelling, and the potential for secondary infection if the barb breaks off in the wound. Rare systemic symptoms include nausea, vomiting, and low blood pressure [15]. Immediate medical evaluation is recommended, especially if the injury is near vital organs or the barb is not fully removed. Sting victims can get advice from lifeguards if they are available, and escalate from there as needed. You can read more about sting treatment here.
To minimize sting risk, beachgoers should heed beach flag warnings – a yellow flag at beach sites indicates moderate hazards like high surf or strong currents, purple flags indicate marine pests like stingrays or jellyfish, while red flags signal more serious conditions [16]. You can read about more flags here. Doing the stingray shuffle (dragging your feet along the ocean floor) is believed to reduce the risk of stings, by allowing them to detect your motion before you step on them. Wearing protective gear like DragonSkin® stingray-resistant surfing booties, can offer another layer of stingray protection.
Footnotes
[1] https://en.wikipedia.org/wiki/Stingray
[2] https://en.wikipedia.org/wiki/Batomorphi
[3] https://en.wikipedia.org/wiki/Potamotrygonidae
[4] https://www.greaterclevelandaquarium.com/ray-discusses-rays/
[5] Blevins E, Lauder GV. Swimming near the substrate: a simple robotic model of stingray locomotion. Bioinspir Biomim. 2013 Mar;8(1):016005. doi: 10.1088/1748-3182/8/1/016005. Epub 2013 Jan 15. PMID: 23318215.
[6] https://en.wikipedia.org/wiki/Batomorph_locomotion
[7] https://en.wikipedia.org/wiki/Batomorphi
[8] Summers, A.P. (2000), Stiffening the stingray skeleton — an investigation of durophagy in Myliobatid stingrays (Chondrichthyes, Batoidea, Myliobatidae). J. Morphol., 243: 113-126. https://doi.org/10.1002/(SICI)1097-4687(200002)243:2<113::AID-JMOR1>3.0.CO;2-A
[9] Nordell, S.E. Observations of the mating behavior and dentition of the round stingray,Urolophus halleri . Environ Biol Fish 39, 219–229 (1994). https://doi.org/10.1007/BF00005124
[10] Nathan S. Hart, Vision in sharks and rays: Opsin diversity and colour vision, Seminars in Cell & Developmental Biology, Volume 106, 2020, Pages 12-19, ISSN 1084-9521, https://doi.org/10.1016/j.semcdb.2020.03.012.
[11] Newton, Kyle & Kajiura, Stephen. (2020). The yellow stingray (Urobatis jamaicensis) can discriminate the geomagnetic cues necessary for a bicoordinate magnetic map. Marine Biology. 3. 10.1007/s00227-020-03763-1.
[12] Lowe, Christopher & Moss, Greg & Hoisington, Greg & Vaudo, Jeremy & Cartamil, Daniel & Marcotte, Megan & Papastamatiou, Yannis. (2007). Caudal Spine Shedding Periodicity and Site Fidelity of Round Stingrays, Urobatis halleri (Cooper), at Seal Beach, California: Implications for Stingray-related Injury Management. Bulletin, Southern California Academy of Sciences. 106. 16-26. 10.3160/0038-3872(2007)106[16:CSSPAS]2.0.CO;2.
[13] https://www.parks.ca.gov/?page_id=31495
[14] Clark RF, Girard RH, Rao D, Ly BT, Davis DP. Stingray envenomation: a retrospective review of clinical presentation and treatment in 119 cases. J Emerg Med. 2007 Jul;33(1):33-7. doi: 10.1016/j.jemermed.2007.03.043. Epub 2007 May 30. PMID: 17630073.
[15] https://www.poison.org/articles/how-to-prevent-and-treat-stingray-injuries-201
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