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Stingrays

Stingrays. Grenada 2015. In the News September 4, 2006. Steve Irwin fatally stabbed in the chest 1962-2006 Batt Reef 2 m.depth Northeast Queensland North of Cairns Bull (short tail) stingray 1.5 m. width largest salt water stingray. In the News September 4, 2006.

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Stingrays

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  1. Stingrays Grenada 2015 ISAM

  2. In the News September 4, 2006 • Steve Irwin fatally stabbed in the chest • 1962-2006 • 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 scalescovering 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 havepectoral finsthat are fused to the sides of their rostrum or "head” • External gill openings are locatedon 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

  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

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

  32. 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

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

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

  35. 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

  36. 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

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

  38. 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

  39. Treatment • Initial treatment can be started by immersion of injured extremity in hot water (preferably 110-115｡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 30-90 minutes

  40. 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

  41. 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

  42. (Himantura Chaophraya) measured 4.2 meters in length Mekong river >1000# stingray

  43. Mekong River Catfish Largest fresh water Fish

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