1. Phylum Echinodermata

2. Introduction Echinoderms are spiny skinned animals Characteristics
5 part radial symmetry
Internal skeleton
Water vascular system
Tube feet

3. Introduction cont. Shared characteristics with us. Internal skeleton
Certain stages of development similar to ours.

4. Introduction Continued
Diverse living areas
Starfish and sand dollars live in shallow water.
Others live in coral reefs or the floor of the ocean.

5. Form and Function Feeding Tube feet pry open shells of bivalves
Carnivores- include many species of starfish
Tube feet pry open shells of bivalves
Flips stomach inside out
Digestive juices flow out
Begin to digest prey inside the prey’s own shell,

6. Form and Function Continued
Feeding continued
Stomach comes back to normal once finished
Leaves empty bivalve shell behind.
They eat: clams, scallops, snails, corals and other echinoderms.

7. Form and Function Continued
Feeding continued:
Filter Feeders
Sea lillies, basket stars, brittle stars
Use tube feet located on flexible arms to capture plankton that float by on water currents.

8. Brittle Star
Basket Star
Sea Lilly

9. Form and Function cont. Feeding continued Herbivores- Sea Urchins
Scrape algae from rocks using their jaw.

10. Sea Urchin w/ Spines
Sea Urchin without Spines

11. Form and Function Feeding continued Detritus Feeders- Sea cucumbers
Move like a bulldozer across the ocean floor.
Take in sand and ocean soil.
Digest organic materials then rest passes out of organism.

12. Different Species of Sea Cucumber

13. Form and Function cont.
Respiration
Tube Feet- Diffusion of CO2 and O2

14. Form and Function cont. Respiration continued
Skin Gills- some species have, look like bumps.

15. Form and Function cont. Excretion
Solid waste- feces exits through the anus (except Brittle Stars, their feces exits through the mouth)
Excrete ammonia through the tube feet or gills.

16. Form and Function Response
They do not have a head, they have a primitive nervous system.
Nerve ring that surrounds the mouth, radial nerves that connect to the rest of the body.
Eyespots located at the tip of each arm.

17. Form and Function Protection Spiny skin not very protective.
Adaptations:
Basket stars, feather stars, spiny sea urchins move very slow
Hide under rocks
Some fish will turn echinoderms over to expose their soft underside and chow down.

18. Form and Function Movement
Tube feet are attached to plates of the exoskeleton with long skinny muscles to help them move.
Sand dollars and sea urchins skeleton is fused together so spines are attached to skleton which are used to creep along.

19. Form and Function Movement continued
Brittle stars and Feather stars have flexible joints so they can use their arms for locomotion
Feather stars swim for short distances.
Sea cucumbers crawl like worms because endoskeleton is very reduced.

20. Form and Function Reproduction
Most are separate sexes, some are hermaphroditic
External fertilization

21. Form and Function Regeneration
If a starfish is pulled into pieces each piece can grow into a new animal.
Used to cause problems for fishermen- would cut up when they were in their nets then wonder they were twice as many when they came back.

23. Echinoderm Classes
Only found in marine environments- no freshwater or terrestrial.
Starfish
Common starfish is also known as (aka) Sea Stars
5+ arms
Carnivores, prey on bivalves

24. Leather Sea Star,
Dermasterias imbricata

25. Echinoderm Classes Brittle Stars Tropical seas, especially coral reefs
Longer, flexible arms
Shed 1 or more arms when attacked or just “run” away.
Filter & detritus feeders
Hide during the day, hunt at night.

26. Echinoderm Classes Sea Urchins & Sand Dollars
Eat large amounts of algae
Heart Urchins and Sand Dollars hide in burrows.
Sea urchins wedge themselves in rock crevices during the day and come out at night.
Sharp spines- some have poison sacks to make them painful.

27. Sea Urchin

28. Echinoderm Classes Sea Cucumber Look like bumpy moving pickles.
Detritus feeders
Found on ocean floor- very deep
One particular sea cucumber releases a glue-like substance when they are attacked. Causes the attackers to become stuck in a huge ball of glue.

30. Echinoderm Classes Sea Lilies and Feather Stars Filter feeders
50 plus long feathery arms
Ancient species
Not common, but used to be (Found in the fossil record)

32. Place in the World Starfish control population of bivalves.
Sea urchins control algae population.
Sea urchin eggs, sea cucumbers are considered delicacies in some parts of the world.
Useful research subjects.