Phylum Echinodermata Flashcards
Phylum Echinodermata Eumetazoa
Yes
Phylum Echinodermata Radiata or Bilatera
Radiata, but bilateria as larva
Phylum Echinodermata Deuterstomia or Protostomia?
Dueterstomia
Phylum Echinodermata Acoelomate, Pseudocoelomate or Coelomate?
Coelomate
Phylum Echinodermata Diploblastic or Triploblastic?
Triploblastic
Phylum Echinodermata Invertebrate or Vertebrate?
Invertebrate
Echinodermata – starfish, sea urchins, sea cucumbers and crinoids
- Three tissue layers – spiny skin – water vascular system
- Adults have radial symmetry – larva are bilateral
- Unique feature – tube feet
- All are aquatic – marine
- Spines hard CaCO3 plates
- Sexual and asexual (Fragmentation and Regeneration) reproduction
- Feed on detritus – some are active predators feeding on other organisms
Phylum Echinodermata Endoskeleton
Calcium Carbonate
Class Crinoidea
Sea Lilies and Feather Stars
Flower shaped – Feathery arms -attached to the sea bottom
Have tube feet and spines but no CaCO3 plates
Many Ordovician Fossils are crinoids
Class Asteroidea
Sea Stars
All have five or more arms (usually in multiples of five) radiating from a central disk
Have prominent tube feet that are manipulated by a water vascular system of tubes and suckers
Have imbedded spines made of CaCO3 plates
Class Ophiuroida
Brittle Stars
Have five slender arms that tend to break easily
Have tube feet and a water vascular system
Have sharp imbedded spines of CaCO3
Class Echinoidea
Sea Urchins and Sand Dollars
Lack the characteristic “arms” of this group
Spherical (sea urchins) or disk-shaped (sand dollars)
Have tube feet and water vascular system
Sea Urchins have prominent sharp spines
Sand Dollars have CaCO3 plates that form a shell like test under the skin
Class Holothuroidea
Sea Cucumbers
Shaped like cucumbers
Lack “arms” and spines
Their CaCO3 plates are highly reduced or absent
The have a curious defense reflex – when threatened by a predator they disgorge their digestive tract to distract the predator – while they creep away to safety
