Starfish Pre-Lab Questions
1. In what phylum are starfish found?
ECHINODERMATA
2. What is the habitat for starfish?
MARINE – Tidal Zone, Rocky Coastal Areas.
3. On what do starfish feed?
BIVALVES – Class in Mollusca – Clams, Muscles,
Scallops etc.
4. What system in their body helps them catch &
hold their food?
Water Vascular System
5. What does echinoderm mean in Greek? Why is
this a good name for this group?
Spiny Skin – Most have an endoskeleton with
plates that project through the skin.
6. Name 2 classes of echinoderms & a member of
each class.
A) Asteroidea : True Starfish
B) Ophiuroidea : Brittle Stars and Basket Stars
7. Where does water enter a starfish? Where
does it leave?
- It enters and leaves through the Madreporite
(Sieve Plate)
8. What type of symmetry did your starfish
have?
RADIAL - Pentaradial
9. What is the upper surface of the starfish
called?
ABORAL - Dorsal
10. What is the lower surface of the starfish
called?
ORAL - Ventral
11. On which surface are these parts of a starfish
visible:
a. Mouth - ORAL
b. Madreporite - ABORAL
c. Suckers ORAL
d. Oral spines - ORAL
e. Eyespots - At Tips of Arms (rays)
d. Ambulcaral groove - ORAL
12. In words, trace the path water takes through
the water vascular system.
Madreporite (Sieve Plate)  Stone Canal  Ring
Canal  Radial Canals  Ampulla of tube foot 
Down Tube Foot
13. What part of the tube foot creates suction to
open clams whenever the starfish feeds?
The suction cup (sucker) being pulled back by
the suction of the ampulla drawing water up.
14. Why do the gonads sometimes appear larger?
Gonads are largest when individual is fully sexually
mature.
15. What type of skeleton, endoskeleton or
exoskeleton, does the starfish have?
ENDOSKELETON
16. Where is the stomach of a starfish located?
What can the starfish do with its stomach when
feeding on clams & oysters?
In the central disc there is a lower cardiac
stomach and an upper pyloric stomach. The
cardiac stomach can extrude out through the
mouth.
17. Name the kingdom, phylum, and class for the
starfish you dissected.
Kingdom – ANIMALIA
Phylum – ECHINODERMATA
Class – ASTEROIDEA