Phylum Echinodermata: “spiny skin”
- sea stars, brittle stars, sea cucumbers, sea lilies, urchins• General Features
– Exclusively marine
– Benthic herbivores, detritovores,
carnivores;
– All habitats/depths
– Bilateral larvae, radial adult
– Endoskeleton
– Non-centralized nervous system
– Water-vascular system
– Non-segmented
– Well developed digestive system
– Cutaneous respiration
– Regenerative Capacity
5 Echinoderm Classes
Figure 33.38 Anatomy of a sea star
Cl. Ophiuroidea
Cl. Asteroidea
Cl. Crinoidea
Cl. Echinoidea
Cl. Holothuroidea
1
Water Vascular System
Tube feet
movies
Echinoidea
Sand dollar
Aristotle’s lantern
Ophiuroidea
2
Crinoids
Tube foot
Food groove
Holothuroidea
Larval Stage
3