A Recent Study of the Marine Hawksbill Turtles' Stomach Contents

Multiple Choice

A recent study of the marine hawksbill turtles' stomach contents revealed that sponges constitute a major portion of their diet.Sponge beds are generally protected from predators by their calcium and silica crystals,but these were found in the turtles' digestive systems.These protective structures are called

A) amoebocytes.
B) osculum.
C) choanocytes.
D) spicules.
E) spongin.