Marine Animals - School of Ocean and Earth Science and ......Chordate Tree Invertebrates Vertebrates...
Transcript of Marine Animals - School of Ocean and Earth Science and ......Chordate Tree Invertebrates Vertebrates...
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OCN 201 Biology Lecture 8
Marine AnimalsVERTEBRATES
The Animal Family Tree
Bilateria
Radiata
Ancestral Protist
Round Worms
Molluscs
Segmented Worms
Arthropods
Chordates
Echinoderms
Cnidarians
Ctenophores
Sponges
Flatworms
Placozoa
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Chordate TreeInvertebrates Vertebrates
Animal with the following features:
• Notochord• Dorsal hollow nerve cord• Pharyngeal slits (originally for feeding, later modified)• Post-anal tail
What is a chordate ?
~4% of animals are chordates
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salps
• Pelagic or benthic• Colonial or solitary
(or alternating)
• Suspension feeders
Tunicates
• Small, fish-like, suspension feeder
• Can swim, but usually stays partly buried (as adults)
Lancelets (cephalochordates)
Amphioxus
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Chordate PhylogenyInvertebrates Vertebrates
A chordate with a vertebral column
95% of all chordates are vertebrates
What is a vertebrate ?
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Vertebrate diversityAmphibians*
6%*Mammals*
9%*
Rep2les*13%*
Birds*17%*
Fish*55%*
Marine vertebrate diversityOther&3%&
Fishes&97%&
marine vertebrates ~= fishes
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• Jawless fishes (Agnatha)
• Cartilaginous fishes (Chondrichthyes)
• Bony fishes (Osteichthyes)
The Major Fish Groups
Agnatha• No jaws; have
rasping mouths
• Earliest appearance of cartilaginous skeleton
• Body covered with skin (not scales)
• Parasites or Scavengers
Lamprey
Hagfish
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• Sharks, Skates, Rays, and Chimaeras• Skeleton of cartilage• Earliest appearance of jaws• skin covered with dermal denticles (like
teeth)
• Carnivores or Planktivores
Chondrichthyes (Cartilaginous Fish)
• Planktivores (filter feeders) are largest • Gaping mouth with small or no teeth• Gill rakers• Manta Ray (7 m across!)• Whale Shark (up to >10 m long!)
Chondrichthyes: Planktivores
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Manta Ray
PlanktivoresWhale Shark
Chondrichthyes: Carnivores
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Cookie-Cutter Shark
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Lateral Line System
sensing movement
• Ampullae of Lorenzini
• Detect very weak electrical signals given off by all living things
• Find food in/on sediments
Electrosensory (sharks and rays)
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Cartilaginous Fish
• 22,000 species• From about 1 cm to 8 m• Surface to ≥ 8370 m• Most numerous, most diverse, most
successful of marine vertebrates
Osteichthyes (Bony Fish)
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• Good sense of sight and smell (except where eyes secondarily lost)
• Auditory• Lateral Line System (water movement,
displacement of water / pressure)
Osteichthyes Sensory Systems
Herbivores
Herbivores (algae)
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mouthfilter:gill rakers
gill opening
H2O
gut
Used by the most successful groupsSardines, anchovies
AnchoviesSardines
Planktivores (Filter Feeders)
CarnivoresParrot Fish
Tuna
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Mola mola: Ocean sunfishUp to 1300 kg and 3 m tip to tip
Most Massive bony fish:
Feeds on gelatinous zooplankton
Bony Fishes
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Chordate PhylogenyInvertebrates Vertebrates
Chordate PhylogenyInvertebrates Vertebrates
Ray-finnedfishes(Ac#nopterygii)Bonyfishes
(Teleostei)
Sturgeonsetc.(Chondrostei)
Car8laginousfishes(Chondrichthyes)
Lobe-finnedfishes(Sarcopterigyii)
Amphibians
Rep8les
Birds
Mammals
Coelacanths
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Reptiles, Birds, and Mammals
• Loggerhead• Leatherback• Hawksbill• Olive Ridley• Green Sea Turtle
(Honu)
Sea turtles
> 2 m long up to 1300 lbs
5 cosmopolitan species
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• Chelonia mydas• Adults herbivorous (macroalgae)• Can submerge for 2 hrs when
resting
• Eggs laid on beaches - 2 months to incubate
• Nesting females return to beach where born (natal beach)
Honu (Green Sea Turtle)
• Crocodile - one living marine species
• Sea snakes - 50 species. Venomous, no gills
Other Marine ReptilesTropical West pacific/Indian Ocean
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Seabirds
• albatross, shearwaters• gulls and terns• pelicans, cormorants,
frigate birds
• penguins
Mammals
• Endotherms (warm-blooded)• Breathe Air• Have Hair• Live Young• Milk Production in Females
Features:
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Marine Mammals (Class Mammalia)
Carnivora - polar bears, sea otter, pinnipeds
Sirenians - dugongs and manatees
Cetaceans - whales and dolphins
CARNIVORA
Enhydra lutris
Sea Otters
Ursus maritimus
Polar Bears
Pinnipeds (seals and sea lions)
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Sirenians
• dugongs and manatees
• Herbivores - eat sea grasses
• Near shore inhabitants of warm tropical waters
• Only ~2300 alive today
• Stellar sea cow hunted to extinction
Cetaceans
Includes the whales, dolphins and porpoises
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Two Cetacean Suborders:
• Mysticetes (11 living species) – large – baleen whales - filter feeders – 2 blowhole openings
• Odontocetes (about 67 species) – smaller – toothed whales, dolphins, and porpoises – 1 blowhole opening
Mysticetes (baleen whales)
Use complex vocalizations or “songs” for communication
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Baleen (Mysticetes)
Humpback Bubble Net
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Odontocetes (toothed whales)
Use squeals, chirps and clicks for communication, echolocation and
stunning of prey
Questions?