1. Spineless Wonders and Other Creatures of
the Deep
- The Oxygen Revolution
- The Diversity of Marine Animals
- Marine Invertebrates and Fish
Reading: 4th Ed., Ch 15 pgs 378-395, 5th Ed., Ch 15 pgs 356-372
Graphics: (top) "Mystery Squid", NOAA and Science, (middle) Lima sea star,
K.Evans, photographer. Courtesy of National MarineSanctuaries Photo Gallery.
(bottom) Red shrimp. National Ocean Service Photo Gallery.
2. Plants - Paving the Way for Marine Animals
The success of early plants changed atmospheric chemistry
Higher oxygen levels favored evolution of animals
Graphic: Garrison, 4th Ed., Fig. 1.15, pg 14, 5th Ed., Fig. 2.10, pg 44
3. The Diversity of Marine Animals
All major animal groups are found in the sea
1/3 of Earth's animal groups are exclusively marine
Marine animals
- span a broad range of complexity
- have evolved diverse strategies for succeeding in the ocean
Graphic: Ribbed jelly fish. Courtesy of National Ocean Service Photo Gallery.
4. Types of Marine Animals
Invertebrates
- soft-bodied
- lack a rigid internal skeleton
Chordates
- stiffened notochord
- transitional between invertebrates and vertebrates
Vertebrates
- fully functional backbone
Graphics: Top: Ghost crab (invertebrate). National Ocean Service Photo Lib.
Middle: Colonial tunicate (chordate). NOAA Photo Library. Bottom: Eagle ray
(vertebrate). M.White Nat. Marine Sancturaries.
5. Sponges - The Most Primitive True Animals
Suspension feeders -no circulatory or digestive system
Widely distributed
Graphics: Left: Garrison, Fig. 15.3b d, 4th Ed., pg 380, 5th Ed., pg 358.
Bottom: Sponge colony. D. Blackwood and P. Valentine, USGS.
6. Cnidaria - Carnivorous Stinging Animals
Jellyfish, anemones, corals
- Stinging cells (cnidoblasts) shoot upward from tentacles penetrate, entangle
or disable prey
-Two forms medusa (jellyfish) and polyp (anemones)
Graphics: Left: Anemone. Collection of Dr. J.P.McVey, NOAA Photo Library. Right:
Garrison, Fig. 15.4, 4th Ed., pg 380, 5th Ed., pg 358.
7. Cnidarian Body Systems
Simple anatomical systems
- food is drawn through the mouth into a digestive cavity
- no distinct "head"
- no circulatory, respiratory or excretory systems
Graphics: (left) Garrison, Fig. 15.6, 4th Ed., pg 382, 5th Ed., pg 360, (right)
Coral polyps, collection of Dr. J.P.McVey, courtesy of NOAA.
8. Worms - Transition to Advanced Animals
Types
Features .
Flat
central nervous system and eye spots
(simple)
Round
flow-through digestive system
Segmented each
segment can have its own
(more complex)
nervous, circulatory, muscular, etc
systems
Graphics: Left: Free-living segmented worm. National Estuarine Research Research
Collection. Right: Polychaete worm. Cordell Bank National Marine Sanctuary Photo
Gallery.
9. The Diversity of Marine Worms
Graphics (clockwise from upper left): Polychaete amphitrite, NOAA National
Estuarine Research Reserve Collection, Tube worms Riftia pachyptila photo by C.
Van Dover OAR/National Undersea Research Program, Coll. of William and Mary,
Flatworm Pseudoceros ferrugineus collection of Dr. J.P. McVey, Tube worms
National Undersea Research Program Collection, Sabellid worm, collection of Dr.
J.P. McVey, tube worms near a Gulf of Mexico hydrocarbon seep OAR/National
Undersea Research Program, Penn. State Univ., Christmas tree worms Spirobranchus
giganteus photo by J. Guttuso. All courtesy of NOAA.
10. Mollusks
Gastropods - snails, nudibranchs
Bivalves - clams, oysters, mussels
Cephalopods - octopus, squid
Most have a foot and a shell
Graphics: Left: Garrison, 4th Ed., Fig. 15.9, pg 385, 5th Ed., Fig. 15.10, pg
363, Top: Octopus. S.Fisher, photographer. Courtesy of National Marine
Sanctuaries Photo Gallery.
11. Abyssal Giants
12. Arthropods - Marine Animals by the Billions
Characteristics:
- exoskeleton
- striated muscle
- articulated movement
Crustaceans:
- most successful class of marine animals
- essential food source for many fish and whales
Graphics: Top: Krill. Courtesy of NOAA Photo Gallery. Bottom: Ampipod. Courtesy
of National Ocean Service Photo Gallery.
13. Echinoderms
- Sea stars, brittle stars, sea urchins, sand dollars, sea cucumbers
- 5-section radial symmetry
- Lack eyes and brains (but makes up for it in guts...)
Graphics: Top: Lima Star. K.Evans photographer. Courtesy of National Marine
Sanctuaries Photo Gallery. Bottom: Sea cucumber. E.Williams, photographer.
Courtesy of National Undersea Research Program.
14. Invertebrate Chordates - Casting a Net
Tunicates (sea squirts) and salps:
- suspension feeders with two body openings
- lose notochord as they develop
- solitary or colonial
- free swimming or attached
Amphioxus
- transitional to vertebrate fish
Graphic: Garrison, 4th Ed., Fig. 15.20b, pg 390, 5th Ed.,. Fig. 15.21, pg 368.
15. Anatomical Comparison - Sponges and Chordates
Even though tunicates and sponges look similar, tunicates have much more
advanced digestive systems
Graphics: Garrison, 4th Ed., Figs. 15.3b (pg 380) and 15.20a (pg 390), 5th Ed.,
Figs. 15.3, pg 358, Fig. 15.21, pg 368.
16. Vertebrate Evolutionary Tree
Vertebrates evolved over 500 million years ago
All classes are found in the modern ocean except amphibians
Graphic: Garrison, 4th Ed., Fig. 15.22, 5th Ed., Fig. 15.23, pg 369.
17. Jawless Fish
Primitive fish
- cartilage skeleton
- lack jaws
- modified fins
- some can survive in fresh or salt water
Examples:
- hagfish
- lamprey
Graphics: (top) Sea lamprey on a lake trout, (center) sea lampreys, (bottom) sea
lamprey mouth, all courtesy of Great Lakes Fishery Commission.
18. Hagfish - Macrame Artists of the Sea
Hagfish can tie themselves in knots - this gives them leverage while feeding
Hagfish defend themselves by producing noxious slime - after the threat is gone,
they slide a knot down their bodies to shed the slime
Economics - hagfish flesh is dried to make "eelskin“ products
Graphic: (top) Garrison, 4th Ed., Fig. 15.23, pg 392, 5th Ed., Fig. 15.24, pg
370, (middle) Hagfish in the wild, courtesy of NOAA, (bottom) Hagfish slime.
19. Cartilaginous Fish
- Ancient group
- Includes sharks, skates and rays
- Bony teeth
- Cartilage skeletons
Many are top-level predators
- feeding by these species helps maintain ecological balance
Others restructure their environment
- many skates and rays burrow into sediments for food, displacing some organisms
and creating habitat for opportunists
Graphics: (top) Eagle ray, M.White Nat. Marine Sancturaries, (bottom) blue
shark, S.Anderson, photographer, courtesy of Channel Islands National Marine
Sanctuary.
20. Sharks and the Food Web
Apex predators vulnerable to overfishing
- excellent sensory systems (smell, vision, lateral line, electroreceptors)
- many years to maturity
- have few young
- need specific habitats for nurseries
In 1999, Atlantic Commercial Shark harvest estimated at 2,265 metric tons1
In 2002, 60 confirmed unprovoked attacks worldwide with 3 fatalities2
Most attacks are "hit and run" due to mistaken identity
1 NOAA Fisheries 2000 Shark Evaluation Annual Report
2 Florida Museum of Natural History
Graphics: (top) White shark, photo by S. Anderson, (bottom) Tiger shark caught
off Hawaii, photo by Dr. J.P.McVey. Both courtesy of NOAA.
21. Bony Fish
- Bony skeleton
- Dominant marine invertebrate
- Very diverse class
Ray-finned fish
- jointed, bony rays support fins
- most common type of bony fish
Lobe-finned fish
- fins supported by fleshly lobes with bones
- ancestors of amphibians
Graphic: (top) Garrison, 4th Ed., Fig. 16.16, pg 429, see 5th Ed., Fig. 16.16,
ph 405, (bottom) Garrison, Fig. 15.28, pg 395, 5th Ed. Fig. 15.29, pg 373.
22. Coelacanth: The Fish That Time Forgot
Group of fish that first evolved about 410 Ma
Adults ~2m long, ~100kg, with four distinct lobe fins that can support its
weight (possibly an adaptation that led to the development of walking appendages
on land)
Until 1930's, believed to have gone extinct ~65Ma, but found recently in waters
off Madagascar and Indonesia
23. Form and Function in Swimming
24. Preview of Next Lecture
- Charismatic Megafauna (Marine Mammals)
- Review for Exam 3 (Exam 3: Tues Nov 15)
Reading:
4th Ed, Ch 15 Secs 35-39, Ch 6 Secs 21-22, Ch 17 Sec 19
5th Ed, Ch 15 Secs 35-38, Ch 6 Secs 24-25, Ch 17 Sec 21
Graphic: Humback whale breaching. Cmmdr. J. Bortniak, NOAA Corps, photographer.
Courtesy of NOAA.