Who needs bones to swim the seven seas? Learn all about marine invertebrates, the ocean's amazing boneless animals in this cool Smithsonian reader. Octopuses, clams, sea worms, even coral: they're all marine invertebrates. Having no internal skeleton gives them an interesting shape--not to mention unusual ways of moving around, getting food, and protecting themselves. Fascinating underwater photography and lively, accessible text draw kids into the watery world of these cool ocean creatures.