1. Stingrays
Grenada 2015
May 2015
ISAM

2. In the News September 4, 2006 Steve Irwin fatally stabbed in the chest
Batt Reef 2 m.depth
Northeast Queensland
North of Cairns
Bull (short tail) stingray 1.5 m. width largest salt water stingray

3. In the News September 4, 2006 He was struck left side of his chest
He was swimming over the stingray, suddenly the ray stopped swimming turned & struck upward like a scorpion stinger with its venomous barb attached to its tail
He is reported to have pulled the detached barb from his chest, then to have died

4. In the News September 4, 2006

5. Incidence of Stingray Attacks
1500 in U.S. each year
Only 3 fatalities in 10 years Australia
Most injury stings on legs
Infrequent stings to be on trunk
Most common cause of serious wound infection in salt water

6. Stingray Barbs & Behavior
The venom apparatus or "sting" of a stingray barb or modified dermal denticle (the scales covering sharks & stingrays) with 1 or 2 ventral grooves filled with venom-producing tissue

7. Stingray Barbs & Behavior
Larger the ray the larger the barb
Over 12 inches long
Up to 4 barbs on one tail
Barbs strike upward like a scorpion
Rays bury in the sand for protection
Reflex of stingrays: voluntary / involuntary
Sharks are ray predators

8. Classification Characterized by their flattened
shape & long, spine-bearing tails,stingrays are unique elasmobranchs & cartilaginous cousins of the sharks
Stingrays have pectoral fins that are fused to the sides of their rostrum or "head”
External gill openings are located on the stingray's ventral side or "underside”

9. Classification
Over 200 species of stingrays in the scientific order Myliobatiformes
giant stingarees (Family Plesiobatidae)
sixgill stingrays (Family Hexatrygonidae)
stingarees (Family Urolophidae)
river stingrays (Family Potamotrygonidae)
whiptail stingrays (Family Dasyatidae)
butterfly rays (Family Gymnuridae)
eagle rays (Family Myliobatidae)
cownose rays (Family Rhinopteridae)
devil rays (Family Mobulidae)

10. Types of Stingrays: Benthic
Stingrays are 2 different general types:
”Benthic" (or bottom) stingrays
”Pelagic" (or swimming) stingrays
Benthic rays, such as the Atlantic stingray often found buried in the sand
Most are rounded or "diamond-shaped" body & their stings located near the middle or lower third of their "tail”
Bottom feeders, these rays generally feed on worms, clams, shrimp, crabs, snails and occasionally fish

11. Types of Stingrays: Pelagic
Spotted eagle ray & manta ray active swimmers "bat-like" shape
Pelagic stingrays have stings that are located close to the body, just behind their pelvic fins
Like bottom rays, most pelagic rays also feed largely on bottom-dwelling organisms
Devil rays are mainly plankton feeders and use paddle-like cephalic or "head" lobes to direct plankton-rich water into their mouths

12. Types or Rays

13. Habitat of Stingrays
Stingrays can be found in both freshwater & marine habitats
Family Potamotrygonidae: river stingrays live permanently in freshwater & unable to survive in marine habitats
Atlantic stingrays living in Florida's St. Johns River spend entire life in freshwater, but can adapt to saltwater

14. Types of Stingrays
Some stingrays don’t have barbs: butterfly & devil ray (Manta)

15. Strange Stingrays Smalltooth sawfish, Pristis
pectinata, is largest & most
distinctive species of ray
in the world

16. Strange Stingrays
Torpedo Ray:
Electric ray has no barb

17. Strange Stingrays
Guitarfish: Type of ray that does not
Have a barb

18. Skates Not have venomous barbs like stingrays Many have sharp thorns
located on dorsal surface
& tails
Live in marine habitats & rarely enter brackish or freshwater environments
Stingrays give birth to live young
Skates lay eggs in leathery capsules sometimes called mermaid's purses
Clearnose skate

19. Clear-nose Skate

20. Stingray Barbs & Behavior
Serrated barbs slice fine as a razor
Indians used barbs for cutting tool
Calcium carbonate barb fragments
Wound healing impaired due to
Necrosis of tissue
Comtamination of fragments & bacteria
Deep penetration and tears with abscesses

21. Stingray: Voluntary / Involuntary Reflexes
Trapped or cornered or distressed
In pain hooked or pulled ashore or in boat
Shadow or swimming closely over ray especially if ray is not covered in sand
Usual ray defense is to hid under sand
Rays are very docile even friendly but always remember they are wild animals

22. Stingray: Voluntary / Involuntary Reflexes
Rays have electric sensors mouth and nose area gives a proximity sensor
Sharks have similar locators to detect rays in the sand
Sharks tend to hover only a few feet above the sand to detect a buried ray
Rays will strike upward if they detect a suspected shark

23. Ampullae of Lorenzini Shark has the greatest
electricity sensitivity known in all animals
Used to find prey hidden in sand by detecting the electric fields inadvertently produced by all fish
Hundreds to Thousands of ampulae
Found in Rays and Skates

24. Venom Apparatus surrounded by cell-rich sheath
Sheath may also produce lesser amounts of venom
Venom is a largely protein-based toxin causes excruciation pain & may also alter heart rate & respiration

25. Venom
Proteinaceous, it can be inactivated by exposure to high temperatures
Immersion of the wound in hot water or application of a heat compress are recommended as an immediate treatment
Not by denaturing of the protein the heat is not that hot but may be related to electrical gate effect blocking the protein effect on the human nerve transmission

26. Skates vs Stingrays ate Skates lay eggs & no stingers only spines/fins
Stingrays have live birth + have stingers of venom
Clear-nosed skate

27. skate
Short tail stingray

28. Skate
Skate: no stinger

29. Largest Stingray: Bull or Short-tailed Ray

30. Venom Vasoconstrictors
Proteins cause arteries & capillaries at injection site to constrict & reduce blood flow
Common among venomous animals
Restricts blood flow to the wound so that the other toxins remain & cause damage without being carried away or diluted by blood flow

32. Symptoms & Signs N&V&D Seizures Fasciculations
Abdominal & muscle cramps
Diaphoresis & severe pain locally
Hypotension
Syncope

34. Venom
5-nucleotidase & phosphodiesterase which are cytotoxins (kill cells/tissue) result in local necrosis (tissue death)
Bacterial infection & severe wounds may take months to heal
Stingray toxin also contains serotonin, which causes severe localized pain lasting up to 48 hours

35. Complications of Stingray barb
Local infection
Tetanus prophylaxis
Halophilic vibrio
Deep wound penetration
Organ or bone
Fragmentation of barb (radio-opaque)
Poor healing

36. Marine pathogens Vibrio vulnificus Aeromonas hydrophila
Edwardsiella tarda
Erysipelothrix rhusiopathiae, Mycobacterium marinum
Streptococcus iniae
Vibrio damsela

37. Stingray Wound
Injury results in a deep puncture & evenomation after the integument over the spine is ruptured
Fatalities are possible if the pericardium, peritoneum, or pleural cavity is perforated

38. Venom
Venom is a heat-labile & water-soluble protein with an IV LD50 of 28.0 mg/kg
Pain is the initial symptom that increases over 1-2 hours & decreases over the following 6-48 hours
Bleeding may be present, and in some cases profuse
May actually lessen the degree of pain

39. Stingray wound Wound commonly becomes ulcerated and necrotic
Secondary infection of the damaged tissue
Osteomyelytis has been reported

40. Rays and Skates Uses Taste like scallops Favorite food for many sharks
NC law allows cookie cutter pieces of rays & skates to be sold as scallops

41. Treatment
Initial treatment can be started by immersion of injured extremity in hot water (preferably ｡F)
Water should be as hot as the patient can tolerate but should not cause burns
Water should be exchanged for more hot water as it cools, for an immersion duration of minutes

42. Treatment
Plain radiographic image of injured area to look for retained barbs or other foreign material
Explore the wound thoroughly & irrigate it Perform any necessary debridement
Remove any foreign body from the wounds: spine,sheath, dirt or sand
Administer tetanus booster as needed

44. Treatment
Assume potentially contaminated wound, allow wound to heal without closure
Most wounds are small, & usually is not an issue
If the wound is very large or gaping, consider loose primary closure
Vinegar may dissolve calcium fragments

46. (Himantura Chaophraya) measured 4.2 meters in length
My be the worlds largest stingray is fresh water
Mekong river
>1000# stingray

47. Mekong River Catfish
Largest fresh water
Fish