Help students when necessary. Fish , like other vertebrates, have a backbone but they breathe through gills. Parasites may cling inside their gills. A pair of pectoral and pelvic fins help steer while dorsal and anal fins stabilize. The swim bladder, located in the body cavity, makes the fish almost weightless in water.
Scales provide protection and camouflage.
Show students grass shrimp and oyster posters. Pass out oyster shells to touch. The first two or three pairs of legs are pinchers. The last pairs are used for swimming. Shrimp are mainly bottom dwellers, living among algae, sea grasses, stones and shells.