1 / 47

Stingrays

Discover the world of stingrays, from their unique classification to their fascinating behavior and the rare instances of attacks. Learn about the various species, habitats, and barbs, and understand the importance of caution around these intriguing creatures.

michellehowe
Download Presentation

Stingrays

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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

More Related