Echinodermata Class: Asteroidea

Question 1

What does the class Asteroidea mean?

Answer 1

Star form

Question 2

What organisms are in Asteroidea?

Answer 2

Sea stars, bat stars, sun stars

Question 3

Name & describe functions of both stomachs of a sea star

Answer 3

Bottom stomach: cardiac stomach - receives ingested food
Top stomach: Pyloric stomach - give rise to ducts that connect to secretory and absorptive structures called pyloric cecae

Question 4

How do sea stars eat?

Answer 4

wrapping itself around bivalve’s mantle margin, tube feet attaches to the outside shell and body wall musculature forces valves apart.

Question 5

3 factors that trigger spawning among sea stars

Answer 5

-photoperiod
-temperature
-gametes released by one individual that results in spawning pheromones that trigger spawning