Baby Cuttlefish Are Cute, Colorblind Killers

The business end of a cuttlefish is no place a small crustacean wants to be. Cuttlefish are hunters who creep around in camouflage—virtually indistinguishable from a gray patch of gravel or a branching green seaweed—then lash out with their tentacles, turning a passing shrimp into shrimp toast. Oh, and they're colorblind. Despite this apparent handicap, though, learning to hunt doesn't take a lifetime. Baby cuttlefish figure it out almost as soon as they hatch. "Newly hatched cuttlefish are mini adults," says Anne-Sophie Darmaillacq of the Université de Caen Basse-Normandie in France. They behave similarly to full-grown cuttlefish, that is, and look like toy versions of their parents. Yet those grownups are long gone. "Parents die after the spawning season," Darmaillacq says. Since cuttlefish are born as orphans, they have to be able to look after themselves right away. For this reason, Darmaillacq and her coauthors wondered how the eyesight of ...