Chelicerates and Echinoderms

1
Chelicerates and Echinoderms

• EQ How are chelicerates and echinoderms
  different from insects and crustaceans?
• 3/12/07

2
Chelicerates

• Examples horse-shoe crabs, spiders, ticks, and
  scorpions

3
Characteristics

• Chelicerae? fangs that stab and paralyze prey
• Pedipalps? grab prey-longer
• 2 body parts cephalothorax and abdomen
• 4 pairs of walking legs/ Horseshoe crab -5 pairs
• Book lungs or book gills

4
Groups of Chelicerates

• Horseshoe crabs
• Heavy plates like crabs
• 5 pairs of walking legs
• Spike like tail for movement
• Arachnids
• Mites, ticks, spiders, scorpions
• Must liquefy their prey
• All spiders produce silk

5
Orb Weaver Spider
6
Fishing Spider
7
Tailless Whipscorpion spider
8
(No Transcript)
9
Echinoderms

• Kingdom Animalia
• Phylum Echinodermata spiny skinendoskeleton
• Definition Spiny skin, internal skeleton,
  radial symmetry, water vascular system and tube
  feet
• Examples sea cucumber, sea star, brittle star,
  sand dollars

10
(No Transcript)
11
Body plan

• There are internal tubes that transfer water.
  Tube feet are located on the bottom. These act
  as suction cups. The stomach is located in the
  center.

12
Form and Function

• Water Vascular system is filled with fluid
• Carries out many essential body functions
• Respiration
• Circulation
• Movement

13
Feeding

• To eat, the sea star will push its stomach out of
  its mouth.

14
Respiration and Circulation

• Water Vascular System
• Internal tubes filled with fluid.
• Carries out respiration circulation and movement.
• This opens to the outside by a madreporite.

15
Excretion and Response

• Excretes solid out the anus
• Cellular wastes exit through tissues
• Response
• Has nerve ring
• Scattered sensory cells, can detect light and
  gravity
• No highly developed nervous system

16
Movement

• Tube feet/ muscles attached to endoskeleton

17
Reproduction

• External fertilization

18
Groups of Echinoderms

• Sea Urchins and Sand Dollars
• Brittle Stars
• Sea Cucumbers
• Sea Stars
• Sea Lilies and Feather Stars