intro to echinoderms notes
TRANSCRIPT
Phylum: EchinodermataPhylum: Echinodermata
The Spiny-skinned AnimalsThe Spiny-skinned Animals
Phylum: Echinodermata
Echino – spinyDerm – skinSpiny-Skinned Animals
Sea Lily – Tunicate Cove, Belize
Echinodermata Characteristics
Bilateral as larvae and then Radial as adultsTriploblasticComplete digestive systemRadial nervous system with no brainWater Vascular System (no blood)
Echinoderms have a unique system called the water vascular system. It allows them to move, eat, and exchange gases with their environment.
Ring canal
Radial canal
Ampulla
Tube Feet
Madreporite
Tube feet on sea stars are located on the ventral side of the arms. They can be pulled into slits called ambulacral grooves.
Tube feet on sea stars are located on the ventral side of the arms. They can be pulled into slits called ambulacral grooves. Water is pumped into the tube feet from the ampullae (see previous slide) to cause the tip of the tube foot towiden into a suction cup.
Tube feet on sea stars are located on the ventral side of the arms. They can be pulled into slits called ambulacral grooves. Water is pumped into the tube feet from the ampullae (see previous slide) to cause the tip of the tube foot towiden into a suction cup. By moving each tube foot in tiny steps in a synchronized fashion, echinoderms are able to walk on them. The steps are so small that the animal appears to be gliding.
Four Classes of Echinoderms
Class: Asteroidea – sea stars
Brittle stars have long, stringy arms. They move by walking with their arms. Their tube feet are like cleats to provided added traction.
Four Classes of Echinoderms
Class: Asteroidea – sea starsClass: Echinoidea – sea urchins
South Water Caye, Belize
Four Classes of Echinoderms
Class: Asteroidea – sea starsClass: Echinoidea – sea urchinsClass: Holothuroidea – sea cucumbers
Sea Cucumbers
Four Classes of EchinodermsClass: Asteroidea – sea starsClass: Echinoidea – sea urchinsClass: Holothuroidea – sea cucumbersClass: Crinoidea – crinoids/sea lillies