When Charlie’s class visits the aquarium, little does anyone know that there is an extra student along for the ride—his goldfish Wishy is stashed in a plastic bag in his backpack. Charlie is determined to teach Wishy everything he finds out, reasoning that if dolphins can learn, so can goldfish. Throughout the trip he confuses many of his classmates by continually whispering to his backpack. But finally, the excitement of his own learning overcomes him and he leaves his backpack behind. The class’s search for the lost pet is so memorable that every student chooses it as the favorite part of the trip. Charlie’s enthusiasm for learning is refreshing and, one hopes, contagious, even though his teaching methods leave a little to be desired, as Poydar points out in both the story and the list of fish facts in the backmatter. Her gouache artwork reflects the text: While the aquarium fish are not very detailed, they are all identified, and the focus is kept on the emotionally expressive faces of the schoolchildren. A novel look at pet ownership. (Picture book. 4-8)