At night, because lighting is so bad anyway, fish tend to have smaller eyes because of the lack of their use. Fishes' mouths tells us how a fish makes its living. A big mouth with sharp teeth tells us that the fish is a predator of other fish and animals. Basically, the smaller the mouth, the smaller the prey. Color can be used for camouflage.
Silvery fish tend to be active in the day where their shininess blends in with sunlight.
One group will do the first activity while the other does the second. After perhaps 15 minutes, they will switch. The below activities are listed individually at the end of this lesson. They can color these and compare them to other students' work. If you can, get butcher paper from the teacher and have the students draw on one big piece.