Stingrays & Skates http://www.bbc.co.uk/nature/life/Stingray Pfauenaugen-Stechrochen_-_Ocellate_river_s wikipedia stingray Characteristics of Rays (and sharks) Belong to Class Chondrichthyes Sharks and rays don’t look similar on the outside, but share a basic anatomy that classifies them together. Sharks and rays are jawed fish lack a swim bladder have cartilaginous skeletons - they lack true bone Special Attributes of Rays (and sharks) Sharks and rays have other interesting characteristics: Both have lateral lines – lines of sensory hair along the length of the body that detect water motion and vibrations Unique to elasmobranchs is electroreception – the ability to sense minute electricity created by muscles and nerves Sharks and rays have organs called ampullae of Lorenzini which you can see as visible pits near their snouts used to detect the electrical current Have a “conveyor belt” of multiple rows of teeth Special Attributes of Rays Superorder Batidoidimorpha Subclass Elasmobranchii consists of the rays, which includes skates, mantas and guitarfish Manta Ray Stingrays Special Attributes of Rays Have an anatomy well suited to life on sandy bottoms where they hide in mud or sand Some are specially adapted to life in midwater such as eagle ray and manta ray Have pectoral fin “wings” that stretch forward over the gills and are fused to the sides of the head Literally fly through the water No longer need a tail for swimming, the tail has become a defensive whip in some species Stingrays family of cartilaginous fish containing nine genera and about 70 species found in all tropical and sub-tropical seas freshwater-only sub-family - the river rays flattened body shape and disc-shaped pectoral fins help stingrays live and hide in sand and mud barbed stinger on the tail is only used in self-defense, often when they are stepped on in shallow waters Ray Anatomy Southern Stingray en.wikipedia.org/wiki/File-Stingray Absolutedivers.com Southern Stingray Opportunistic forager, feeding on small crustaceans such as shrimp and crabs, mollusks, bony fish and lancelets Feeds by opening wing-like pectoral fins and expelling water to disturb sand and expose prey Often found singly or in pairs Population density may equal 245 per sq. km in shallow breeding/ nursery grounds Bottom-dwelling Lie partially buried in sediment Southern Stingray flattened, diamond-shaped body has sharp corners, making it more angular than the discs of other rays top - dorsal side of the body varies between olive brown and green in adults, dark grey in juveniles, while ventral underside is white Slender tail has long serrated spine at the base Covered in venomous mucous Used for self-defense Not fatal to humans but incredibly painful if stepped on The Southern Stingray Zooborns.typepad.com Eyes are on top of head near spiracles Water enters Spiracles while ray is lying on the seabed Water bypasses mouth and exits through gill flaps Females (150 cm) grow larger than males (67cm) in width Southern Stingray- Scientific name: Kingdom: Animalia Phylum: Chordata Class: Chondrichthyes Subclass: Elasmobranchii Order: Myliobatiformes Family: Dasyatidae (whiptail stingrays) Genus: Dasyatis Species: D. americana Stingray city Newswise.com discountexcursions.com Short-tailed Stingray Dasyatis_brevicaudata_(Short-tail_stingray) Blue-spotted Stingray ribbon-tail is rounder with brighter blue and more vivid spots blue-spotted stingray is larger age estimate from one to 18 years of age. preyed on by the killer whale & hammerhead shark targeted by many parasites such as tapeworms, flatworms, and flukes found in SE Asia Favorite catch of fishermen Blue-spotted Stingray Is ovoviviparous – embryos are in eggs within mother’s body until they hatch Embryos receive nourishment from uterine fluid Give birth up to 7 pups per litter Range from 6 to 13 (15 to 33 cm) inches at birth preys on many fish and small mollusks, crabs, and worms overpowers its prey by pinning them to the bottom of the seafloor with its fins does not have teeth, instead it has food-crushing plates on the sides of its mouth