A stingray injury is caused by the
venom
Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...
ous tail spines, stingers or
dermal denticle
A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scale (zoology), scales, which can also provide effective Underwater camouflage, camouflage through the us ...
s of
rays in the order
Myliobatiformes
Myliobatiformes (), commonly known as stingrays, are one of the four orders of batoids, cartilaginous fishes related to sharks. They are members of the subclass elasmobranchs. They were formerly included in the order Rajiformes, but more recent ...
, most significantly those belonging to the families
Dasyatidae,
Urotrygonidae
Urotrygonidae is a family of rays in the order Myliobatiformes, commonly referred to as the American round stingrays or round rays. They are native to the tropical and warm temperate marine waters of the Americas. There are 20 recognized spec ...
,
Urolophidae
The Urolophidae are a family (biology), family of Batoidea, rays in the order Myliobatiformes, commonly known as stingarees or round stingrays. This family formerly included the genera ''Urobatis'' and ''Urotrygon'' of the Americas, which are pre ...
, and
Potamotrygonidae
River stingrays or freshwater stingrays are Neotropical freshwater fishes of the family (biology), family Potamotrygonidae in the Order (biology), order Myliobatiformes, one of the four orders of Batoidea, batoids, cartilaginous fishes related to ...
.
Stingray
Stingrays are a group of sea Batoidea, rays, a type of cartilaginous fish. They are classified in the suborder Myliobatoidei of the order Myliobatiformes and consist of eight families: Hexatrygonidae (sixgill stingray), Plesiobatidae (deepwate ...
s generally do not attack aggressively or even actively defend themselves. When threatened, their primary reaction is to swim away. However, when attacked by predators or stepped on, the stinger in their tail is whipped up. This is normally ineffective against
shark
Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...
s, their main
predator
Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...
.
Depending on the size of the stingray, humans are usually stung in the lower limb region.
Stings usually occur when swimmers or divers accidentally step on a stingray,
but a human is less likely to be stung by simply brushing against the stinger. Those who enter waters with large populations of stingrays are advised to slide their feet through the sand rather than taking normal steps, as the rays detect the vibrations in the sand and swim away.
There are reports of stingers breaking off in wounds, but this may be rare.
This would not be fatal to the stingray as it will be regrown at a rate of about per month (though with significant variations depending on the size of the stingray and the exact species). Contact with the stinger causes local trauma (from the cut itself), pain, swelling, and muscle cramps from the venom, and possible later infection from bacteria
or fungi.
Immediate injuries to humans include
envenomation
Envenomation is the process by which venom is injected by the bite or sting of a venomous animal.
Many kinds of animals, including mammals (e.g., the northern short-tailed shrew, ''Blarina brevicauda''), reptiles (e.g., many snakes), spiders, i ...
, punctures, severed
arteries
An artery () is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in ...
and
vein
Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and feta ...
s, and rarely death.
Fatal stings are very rare;
the most famous case is when Australian wildlife expert
Steve Irwin
Stephen Robert Irwin (22 February 19624 September 2006), known as "the Crocodile Hunter", was an Australian zookeeper, Conservation movement, conservationist, television personality, wildlife educator, and environmentalist.
Irwin grew up ar ...
died in 2006, which was only the second case recorded in Australia since 1945. In Irwin's case, the stinger penetrated his
thoracic wall
The thoracic wall or chest wall is the boundary of the thoracic cavity.
Structure
The bony skeletal part of the thoracic wall is the rib cage, and the rest is made up of muscle, skin, and fasciae.
The chest wall has 10 layers, namely (from su ...
, causing massive trauma.
Signs and symptoms
Symptoms may include nausea, vomiting, diarrhea, extreme pain at the wound, muscle cramps, and a laceration at the puncture site. There have been cases of severe consequences which may include embedded spines, infection, hypotension, and even possible amputations or death. Pain normally lasts up to 48 hours, but is most severe in the first 30–60 minutes and may be accompanied by nausea, fatigue, spreading cramps, headaches, fever, and chills. Stingray wounds have also been found to bleed for a relatively long time following the initial puncture, although there is no evidence that the secreted
venom
Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...
possesses
anti-coagulant properties, as some have previously believed.
Pathophysiology
The barb is covered with rows of flat spines, composed of vasodentin. Vasodentin is an incredibly strong cartilaginous material which can easily cut through flesh. The undersides of the spines contain two longitudinal grooves which run along the length of the spine and enclose venom-secreting cells. Both the venom-secreting tissues and vasodentin are enveloped in an
epidermis
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and Subcutaneous tissue, hypodermis. The epidermal layer provides a barrier to infection from environmental pathogens and regulates the ...
that tears open when the barb is plunged into a victim. Some spines may break off as the barb exits the wound and stay within the victim, causing prolonged
envenomation
Envenomation is the process by which venom is injected by the bite or sting of a venomous animal.
Many kinds of animals, including mammals (e.g., the northern short-tailed shrew, ''Blarina brevicauda''), reptiles (e.g., many snakes), spiders, i ...
.
Treatment
Treatment for stings may include application of hot water, which has been shown to ease pain.
Multiple theories as to the mechanism of pain relief from hot water have been suggested. A theory that hot water denatures the stingray venom has been questioned because the temperatures required would need to penetrate deeply into the puncture wound and would likely cause thermal damage to surrounding tissue. Other proposed mechanisms include modulation of pain receptors in the nervous system through mechanism such as the gate control theory and the diffuse noxious inhibitory control theory.
Antibiotics
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...
may be administered to prevent
infection
An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...
if there is a delay in treatment, if the wound is deep, or if there is a large amount of foreign material in the wound.
Pain may be treated with
local anesthetic
A local anesthetic (LA) is a medication that causes absence of all sensation (including pain) in a specific body part without loss of consciousness, providing local anesthesia, as opposed to a general anesthetic, which eliminates all sensati ...
in and around the wound, a
regional nerve blockade, or
parenteral
In pharmacology and toxicology, a route of administration is the way by which a drug, fluid, poison, or other substance is taken into the body.
Routes of administration are generally classified by the location at which the substance is applied. ...
opiate
An opiate is an alkaloid substance derived from opium (or poppy straw). It differs from the similar term ''opioid'' in that the latter is used to designate all substances, both natural and synthetic, that bind to opioid receptors in the brain ( ...
s such as intramuscular
pethidine
Pethidine, also known as meperidine and sold under the brand name Demerol among others, is a fully synthetic opioid pain medication of the phenylpiperidine class. Synthesized in 1938 as a potential anticholinergic agent by the German chemist Ot ...
.
Local anesthetic may bring almost instant relief for several hours.
Vinegar
Vinegar () is an aqueous solution of diluted acetic acid and trace compounds that may include flavorings. Vinegar typically contains from 5% to 18% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting ...
and
papain
Papain, also known as papaya proteinase I, is a cysteine protease () enzyme present in papaya (''Carica papaya'') and mountain papaya (''Vasconcellea cundinamarcensis''). It is the namesake member of the papain-like protease family.
It has wi ...
are ineffective.
See also
*
Weever
*
Scorpion fish
*
Stone fish
*
Snake bite
A snakebite is an injury caused by the bite of a snake, especially a venomous snake. A common sign of a bite from a venomous snake is the presence of two puncture wounds from the animal's fangs. Sometimes venom injection from the bite may ...
*
Skin lesion
A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this ...
*
Findlay E. Russell
* ''
Odysseus Acanthoplex''
References
{{DEFAULTSORT:Stingray Injury
Parasitic infestations, stings, and bites of the skin
Fish attacks
Myliobatiformes