An Elementary School Science Teacher Decided to Liven Up the Classroom

Multiple Choice

An elementary school science teacher decided to liven up the classroom with a saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod varieties. Lastly, she added some vertebrates-a parrotfish and a clownfish. She arranged for daily feedings of copepods and feeder fish.
-If the teacher had used a dissecting microscope to examine the outer surfaces of the empty bivalve shells, the teacher would probably have seen marks that had been left by

A) jaws.
B) nematocysts.
C) tubefeet.
D) a lophophore.
E) a madreporite.