Readings:  Ch 15, pgs 406-409 and Ch. 16, p. 461-464

This is a text version of the notes presented in class.

Feel free to email the instructor (alisonjs@kent.edu) with any
comments about the format and ease of use of these online notes.

1.Spineless Wonders - Marine Invertebrates

2. 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

3. Types of Marine Animals
Invertebrates
- soft-bodied
- lack a rigid internal skeleton
Chordates
- stiffened notochord
- transitional between invertebrates and vertebrates
Vertebrates
- fully functional backbone

4. Examples of Marine Animals
Invertebrates:
 - sponges
 - coral, jellyfish, anemones               SIMPLE
 - worms
 - mollusks (e.g., snails, clams, oysters)
 - arthropods (e.g., crabs, shrimp, copopods)
 - echinoderms (e.g., sea stars, urchins)
Invertebrate Chordates:
 - sea squirts (tunicates)
 - salps
Vertebrates:
 - fish
 - reptiles (e.g., sea snakes, turtles)
 - birds                           MORE COMPLEX
 - mammals (e.g., whales, sea lions, otters)

5. Sponges - The Most Primitive True Animals
Suspension feeders -no circulatory or digestive system
Widely distributed
Graphics:  Garrison, Fig. 15.3b-d, pg 410.

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)
Garrison,
  Fig. 15.4, pg 411.

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  Garrison, Fig. 15.6b, pg 412
 

8. Worms - Transition to Advanced Animals (see graphical version of notes for accurate reproduction
   of this table)
Types      Features
Flat        central nervous system and eye spots       simple
Round     flow-through digestive system
Segmented   each segment can have its own nervous   more complex
        circulatory, muscular, etc systems
 

9. Mollusks
Gastropods - snails, nudibranchs
Bivalves - clams, oysters, mussels
Cephalopods - octopus, squid
Most have a foot and a shell
Graphics: Left: Garrison, Fig. 15.10, pg 416.
 

10. 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

11. Abyssal Giants
Most deep-dwelling animals are small, but some mollusks and arthropods are not
Best known - the giant squid of seafaring legends (and reality)
Gigantism may offer specific advantages in the deep sea
 

12. 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...)
 

13. Invertebrate Cordates - Casting a Net
Tunicates (sea squirts) and salps:
- suspension feeders with two body openings
- lose notochrord as they develop
- solitary or colonial
- free swimming or attached
Amphioxus
- transitional to vertebrate fish
Graphic: Garrison, Fig. 15.20a and b, pg 422.

14. Anatomical Comparison -  Sponges and Chordates
Even though tunicates and sponges look similar, tunicates have much more advanced digestive systems
Graphics:  Garrison, Figs. 15.3b (pg 410) and 15.20a (pg 422).

15. Most of the Zooplankton are crustaceans!
Plankton = drifting or weakly swimming organism
Zooplankton = animal members of the plankton classification
Many zooplankton are primary consumers
Examples: copepods, jellyfish, juvenile crabs

16.  Coral Reefs – the rainforests of the sea
•- Largest animal-built structures on Earth (Great Barrier Reef = 2500 km long)
•- Composed of coral animal skeletons
•- Accumulation of skeletons gradually forms the reef
•- Found in brightly lit water (5-10m)
•- Reefs grow slowly (1-10 cm/yr) and are sensitive to changes in sea level and temperature

 
17.  •Coral reefs form in clear, shallow water
•Coral accounts for only about half of reef biomass
•- Competition for space and food is intense
•- Biomass is rapidly recycled
 

18.  Coral reefs are diverse marine communities sustained by invertebrates and home to many vertebrates.
Important economic notes about coral reefs (from NOAA):
a. about 50% of U.S. fisheries depend on coral reefs for part of the fish life cycle
b. new drugs to fight diseases have been developed from coral reef organisms by the pharmaceutical industries
c.-about 25% of the food catch in developing countries comes from reefs
 d.  they are a major source of income through tourism

19. Coral Reef Communities have Global Distribution in Tropical Oceans
 Limited by Surface Water Temperature
 No Reefs in Sea Water Colder than 18C = 65 F
 Optimum Temperature Range  23 – 25 C = 74-77 F

20.  Symbiosis!  Critical in the Reef community, and key to high Biodiversity
 Mutualism:  algae and corals work together and both benefit.
  Algae inside each coral polyp provide oxygen to the coral
  Coral provides carbon dioxide and fertlizer (waste)
 Result:  corals have access to more oxygen, can make the BIG calcium carbonate structures we see as coral reefs.

21.  Coral Bleaching-When the algae inside corals is expelled…
 When the algae leave the corals, coral bleaching occurs
 If the algae can re-enter the coral communities within a short period of time, coral health is okay
 If the algae do not re-enter the coral structure, the corals die.
 Corals have a bleached white look to them when this happens

22.  Why bleaching?
Believed to be linked to unusually warm temperatures. When water temperature climbs more
than 1 degree above maximum values for a region, and holds for a week, bleaching can begin.

 NOAA has a satellite to monitor this.  A coral bleaching index has been developed,
and 24 major reefs around the world are monitored for bleaching conditions using the satellite.

23.  Next Lecture:  Sustainable Marine Fisheries?
Focus Question:  Where have all the fish gone?
ch 17, pgs 484-490