Subclass Actinopterygii The ray-finned fishes Other Orders - Tetraodontiformes – Pufferfish, burrfish and porcupinefish - mostly marine, but a few freshwater species – Tetraodotoxin or tetrodoxin Other Orders - Tetraodontiformes Fugu – Tetraodotoxin or tetrodoxin Other Orders - Tetraodontiformes Ocean Sunfish – 3 species Most fecund vertebrate - >300 million eggs Other Orders – Pleuronectiformes - flatfishes • Benthic, mostly marine - both eyes on same side of head • Eyes on both sides as juveniles, one migrates to other side as individual matures • Both left and right eyed families Other Orders - Pleuronectiformes • 570 species - flounder, soles, halibut Other Marine Vertebrates Class Reptilia Order Testudines - Sea turtles Family Dermochelyidae Family Cheloniidae - 1 species - 6 species Other Marine Vertebrates – sea turtles Family Dermochelyidae Family Cheloniidae - all listed or protected by at least one international conservation organization - usually have both herbivorous and carnivorous life stages - associated with coral reefs during two life-stages 1) immature (growth) and adult foraging (before reproductive activities) 2) pre-nesting by females Other Marine Vertebrates – sea turtles Family Dermochelyidae Generalized life history Family Cheloniidae Other Marine Vertebrates – sea turtles Family Dermochelyidae - largest turtle in the world – up to 6 ft - only turtle that is functional endotherm - can raise body temperature 18 C above ambient water temp - can dive to 1230 m (4,000 ft) - diet is 90% jellyfish Leatherback Other Marine Vertebrates – sea turtles Family Dermochelyidae - Leatherback esophagus is lined with spines to prevent jellyfish from swimming out Other Marine Vertebrates – sea turtles Family Dermochelyidae - Leatherback body temperature is maintained above surrounding seawater - counter-current blood flow system in flippers - thermal inertia - large size and thick layer of fat under skin counter-current blood flow Other Marine Vertebrates – sea turtles Family Cheloniidae – Loggerhead Turtle Flatback Turtle Hawksbill Turtle Olive Ridley Turtle Other Marine Vertebrates – sea turtles Family Cheloniidae Kemp’s Ridley Turtle - rarest of the marine turtles - ~2000 nests in one location Other Marine Vertebrates – sea turtles Family Cheloniidae Green Turtle – most common marine turtle - 20 nesting locations Family Dermochelyidae Family Cheloniidae Sex Determination In most turtles, sex is determined by the incubation temperature of the nest. This is called temperature dependent sex determination (TSD). There are three major patterns of TSD. A. Males at high temps B. Males at low temps C. Males at intermediate temps Conservation of marine turtles - By-catch - Poaching/Products - Predation - Disease - Pollution Conservation of marine turtles - By-catch: both long-line fishing and shrimp fishing/trawling TEDs Conservation of marine turtles - Poaching - turtle products Conservation of marine turtles - Predation Conservation of marine turtles -Disease - fibropapilloma tumors herpes type virus – no known cause Conservation of marine turtles -Pollution •Light plastics Other marine reptiles Order Squamata Family Elapidae - sea snakes (also includes cobras, kraits, coral snakes) - ~ 70 species are marine all marine species are limited to Indian and Pacific Oceans most species are fully aquatic, never leaving the water strong neurotoxins, but rarely aggressive Olive seasnake Yellow-bellied seasnake Other marine reptiles Family Elapidae Venom delivery mechanism Proteroglyphousa single, fixed, hollow fang on the anterior of each maxilla. Other marine reptiles Family Elapidae - toxicity Venom toxicity - The most common measure of toxicity is the LD-50. This is the amount of a substance that is required to kill 50% of the test animals (e.g. mice or rats) in one dose. Name LD-50(mg/kg) Box Jellyfish Taipan Brown Snake Yellow Sea Snake Chinese Cobra Pufferfish Timber Rattlesnake 0.02 -0.04 ? 0.025 0.0365 0.067 0.29 0.334 5.1 Range South Pacific/Australia Australia Australia Pacific Ocean China tropical oceans North America Marine Mammals – Class Mammalia • Mammals first appear in fossil record about 220 mya • at least three lineages have invaded the marine environment Carnivora 1 species Pinnipedia 34 Sirenia 4 Cetacea 90 Marine Mammals – Class Mammalia Most important adaptations - conservation of body heat – large size, blubber - extremely efficient at absorbing/conserving oxygen - carry higher conc.of red blood cells, more hemoglobin in blood - muscles carry more myoglobin Marine Mammals – Class Mammalia - extremely efficient at absorbing/conserving oxygen 4-5 min. Up to 30 min. Up to 30 min. Over an hour Marine Mammals – Class Mammalia Carnivora Pinnipedia Found in cold waters Tail is modified pair of hindlimbs All are carnivorous Most reach large body sizes – conform to Bergmann’s Rule Marine Mammals – Class Mammalia California Harbor seal – 6’ Elephant seal – 20’ Bergmann’s Rule (1847) – within a given group of organisms, those with larger body sizes will be found at higher latitudes Larger animals have a lower surface area to volume ratio – radiate less heat dugong manatee Found in warm waters, fully aquatic All are the only herbivorous marine mammals Have lost hindlimbs entirely Three manatee species occur in Atlantic Ocean coastal areas - Dugong occurs from East Africa to western Pacific islands All four species of conservation concern, all listed as CITES species CITES = Convention on the International Trade in Endangered Species Commander Islands Stellar’s Sea Cow Described by science in 1741 Extinct by 1768 Marine Mammals – Class Mammalia Cetaceans Mostly found in colder waters – warmer waters for reproduction Most complete transformation to aquatic life • very streamlined bodies • loss of hindlimbs • strong convergent evolution Marine Mammals – Class Mammalia Cetaceans Most complete transformation to aquatic life • very streamlined bodies – speeds up to 40 mph • blowhole at top of head – some species can empty and refill lungs in 2 second • most efficient use of oxygen •Best developed system of echolocation Marine Mammals – Class Mammalia Cetaceans Two groups – Baleen Whales 18 species Toothed Whales 72 species