 |
|
|
![Dasyatis pastinaca ( ) [ Original photo copyright permission provided by FishBase ]](images/marine_life/MVP000221.jpg)
|
|
Class: Elasmobranchii (sharks and rays)
|
|
Order: Myliobatiformes
|
|
Family: Dasyatidae
|
|
Genus: Dasyatis
|
|
Species: pastinaca
|
Common Names
Common Stingray
|
|
|
|
|
|
Taxonomy and Biology
|
|
Size: Maximum disc width 60 cm
|
Habitat
Often found in along shallow coastal tropical waters.
|
Habits
Observed lying on the bottom of the flats and bays, shoal lagoons, river mouths and patches of sand between coral area. They could swim rapidly by undulating their pectoral fins. Sometimes they are found swimming near the surface. Most often they are completely or partially buried in the sand or mud with only tail, eyes and spiracles exposed.
Pectoral fins are used to dig in to the floor to excavate prey.
|
Prey
Worms, molluscans, crustaceans, small fishes.
|
|
|
|
Venom
|
General: Neurotoxins
Probably not present
|
General: Myotoxins
Probably not present
|
General: Procoagulants
Probably not present
|
General: Anticoagulants
Probably not present
|
General: Haemorrhagins
Probably not present
|
General: Nephrotoxins
Probably not present
|
General: Cardiotoxins
Probably not present
|
General: Necrotoxins
Probably not present
|
General: Other Toxins
Unknown
|
|
|
|
Clinical Effects
|
General: Dangerousness
Mild envenoming only, not likely to prove lethal from venom, but mechanical trauma potentially lethal
|
|
General: Rate of Envenoming: Unknown
|
|
General: Untreated Lethality Rate: Unknown but lethal potential cannot be excluded
|
General: Local Effects
Local effects include both venom-induced pain and pain, swelling, bleeding due to mechanical trauma
|
General: Local Necrosis
Primary venom necrosis does not occur, but tissue damage can result in secondary necrosis
|
General: General Systemic Effects
Systemic symptoms are uncommon, but nausea, vomiting, hypotension and collapse can occur.
|
General: Neurotoxic Paralysis
Does not occur, based on current clinical evidence
|
General: Myotoxicity
Does not occur, based on current clinical evidence
|
General: Coagulopathy & Haemorrhages
Does not occur, based on current clinical evidence
|
General: Renal Damage
Does not occur, based on current clinical evidence
|
General: Cardiotoxicity
Rare, usually secondary
|
General: Other
In cases of major mechanical trauma, significant tissue damage can occur and if major vessels are severed, exsanguination can occur. Similarly, if the chest or abdomen are punctured, severe, even lethal internal injury can occur. This injury may not be immediately apparent, delayed death being possible.
|
|
|
|
First Aid
|
|
Description: First aid for Stingray stings
|
Details
1. The victim should immediately leave the water.
2. Loose broken stings in limb wounds, away from major blood vessels, can be gently removed. If force is required, leave the sting alone. Stings to the chest and abdomen, in general, should be left untouched, as removal may cause further damage and endanger the patient. In particular, stings to the chest wall, near the heart, can prove lethal and inexpert removal of the sting can precipitate rapid collapse and death.
3. The wound should not be rubbed, or stings crushed as this may worsen the local effects of the sting.
4. There may be significant tissue injury and bleeding. Staunch bleeding by application of local pressure. If necessary, apply a bandage to maintain local pressure over the wound. Only if there is severe bleeding, caused by damage to major blood vessels, apply a tourniquet above the wound, to a single-boned part of the limb (thigh for leg; upper arm for arm) to control the bleeding. Tourniquets are effective at controlling bleeding, but in doing so, deprive the limb of oxygen, so cannot be left on for more than 30-45 minutes, or they will cause permanent injury. They therefore require regular release for short periods.
5. The use of immersion in hot water is controversial. Some authorities suggest that immersing the stung limb in hot water may reduce pain. Others suggest it is useless. For stingray injuries, experience suggests hot water immersion is often very effective at providing pain relief and therefore should always be considered. However, it is potentially hazardous, if used incorrectly, as it may cause burn injuries. If used, immerse the opposite limb to that stung in water which is hot, but bearable with prolonged contact. It should not be so hot as to cause pain. Then immerse the stung limb as far as necessary to include the sting area. Keep both limbs in the water for 15-20 minutes, providing there is relief of pain. If there is no relief of pain in this time, abandon the immersion. If pain has subsided, it may return on removal from the water, in which case, reimmerse for a further 15-20 minutes. Repeat this process up to 4 times. If after 1-2 hours, the pain is still severe on removal from hot water, then other forms of pain relief may be required, but these will require medical intervention.
6. Transport the victim to medical care as soon as safely possible, except where the wound is very minor and pain has been easily and fully controlled and the victim has current anti-tetanus immunisation.
7. All stingray wounds to the chest, abdomen, or neck are potentially very serious, even if the wound looks minor and no sting barb is visible. All such cases require urgent hospital assessment.
|
|
|
|
Treatment
|
Treatment Summary
Stings by marine stingrays are generally associated with significant local pain and physical trauma. Treatment is directed at dealing with these problems, as envenoming is not a major issue (other than any pain-producing effects of the venom).
Initial pain is often responsive to immersion of the stung area in hot (45C, not scalding) water for an hour (ensure no thermal injury occurs). Beyond this, analgesia can be provided by an escalating scale, from oral, through parenteral analgesics, to regional anaesthetic nerve block.
The wound should be inspected for retained sting fragments and these removed. Major bleeding following transection of vessels should be staunched. Beware wounds where the sting has penetrated a body cavity, either the abdomen, or the chest. Penetrating injuries over the heart can prove lethal. Beware early or late haemopericardium.
Stingray wounds can develop late necrosis and secondary infection. Beware tetanus.
|
Key Diagnostic Features
Immediate severe local pain, lacerated wound after walking in shallow (usually sandy) water, rapid local swelling, development of local necrosis/chronic ulceration uncommon, but possible.
|
General Approach to Management
First priority is relief of pain and staunching bleeding if major vessel transected. Thereafter symptomatic care, good wound care.
|
Antivenom Therapy
No antivenom available
|
|
|
|
