1. The Echinoderms
Phylum Echinodermata

2. Echinoderms Marine Sea stars Brittle stars Sea urchins Sea cucumbers
Sea lilies

3. Brittle Star

4. Sea Urchin

5. Aristotle’s Lantern – chewing mechanism attached to teeth - circular

6. Sea Cucumber

7. Sea Lily

8. Found in all oceans/at all depths
Most common animal in extreme depths
11,000 m – Philippine Trench

9. No parasitic/mostly symbiotic
Many other animals live on and in echinoderms
Algae/protozoa/ctenophores/snails/clams fish etc.
Particle feeders/predators
Scavengers/browsers/deposit or filter feeders

10. Very unusual group of animals
Confusing to scientist even today
Name is derived from their external spines
2 Sub phyla/6 classes
Fossil record dates back to the Cambrian period

11. Subphylum Pelmatozoa Stalk animal Connected to a substrate
Class Crinoidea – lily form
Sea lilies
Feather stars

12. Subphylum Eleutherozoa
Free animal – not bound
Class
Concentricycloidea- sea daisies – center form
Asteroidea- sea stars ( star fish) – star form

13. Ophiuroidea- brittle stars – snake form
Echinoidea- sea urchins – hedgehog form
Holothuroidea- sea cucumbers – sea cucumber from

14. Unusual Characteristics
Free moving – Radial Symmetry
Mirror image more than 1 plane
Bilateral larva- Radial Adults – results in 90% reorientation of body axis
Very complex internal – Radial symmetry
Coelom has been transformed into a water vascular system (system of tubes and ducts) that uses hydraulic power

15. Hydraulic power is used to operate tube feet – small muscular fluid filled tubes
Food gathering/locomotion
Endoskeleton of dermal ossicles – can fuse together to form plate of armor
Ambulacral area –mouth to tip of each arm
Miniature jawlike pinsers(pedicellariae) can have poison glands(little foot)

16. Echinoderms Echinoderms/chordates have common ancestor
Evolutionary history very unknown/has made them different from any other animal
Deuterostome -pattern of development – anus forms first – they have this in common with vertebrates
Protostome – all other invertebrates – mouth forms first

17. Characteristics Nonmetameric body Radial symmetry
5 or more radiating areas
No cephalization – no head or brain
Tactile/photo/chemo
statysts
Nervous system has circumforal ring and radial nerves
2 or 3 systems of rings at different levels
Complete digestive system – usually coiled

18. characteristics
Madreporite or sieve plate takes water in to water vascular system
Respiration – dermal branchiae, tube feet, respiratory tree
Excretory organs absent
Cannot osmoregulate
No brackish water capabilities

19. Reproduction Sexes usually separate Some hermaphroditic
Multiple gonads
Ducts release gametes
Fertilization is usually external
Egg develops into free swimming larva
Bilateral symmetry

20. Regeneration Sea stars can regenerate lost limbs
Can take months to regenerate
Also possess autonomy- can self amputate injured piece of arm or part
Some species can regenerate a new sea star from a lost arm if it contains part of the central disc