Phylum Echinodermata

Question 1

what are the 5 classes in this phylum?

Answer 1

1) Holothuroidea
2) Crinoidea
3) Echinoidea
4) Ophiuroidea
5) Asteroidea

Question 2

describe the phylum echinodermata

Answer 2

• ‘spiny skinned’ animals
• secondarily radially symmetrical
• tube feet
• ossicles
• water vascular system that operates podia

Question 3

what are in the class Holothuroidea and describe them?

Answer 3

sea cucumbers

- fleshy body with tentacles surrounding the mouth

Question 4

what are in the class Crinoidea and describe them?

Answer 4

sea lilies (stalked) and feather stars (have lost stalks) 
- flower like and mouth at the top

Question 5

what are in the class Echinoidea and describe them?

Answer 5

sea urchins

• fused ossicles
• show a degree of bilateral symmetry

Question 6

what are in the class Ophiuroidea and describe them?

Answer 6

brittle stars

star shaped with 5 arms and a central disc

Question 7

what are in the class Asteroidea and describe them?

Answer 7

star fish
star shaped - central disc not as obvious as brittle stars
- some have long arms some short
- some have > 5 arms