Children's book.
Trying to find the title of a book I read as a kid. A group of animals live together in a zoo.. one of them is a lemur who speaks very timidly. The zoo acquires a new animal, a rare coelecanth - a giant fish from the Indian Ocean. The other animals decide that the fish is unhappy, so they concoct a scheme to break him out and return him to the ocean. I know this book exists, but much Googling has failed to find it.