Cuttlefish peer out of clear eggs for first lessons in dinner
Cuttlefish could be the first animals shown to learn visually before birth or hatching, researchers say.
Cuttlefish embryos that develop in their translucent eggs with crabs nearby hatch into youngsters with a distinct preference for eating crabs, says Ludovic Dickel of the University of Caen in France. Without that pre-hatch view of crabs, the little cuttlefish attack shrimp in preference to crabs, he and his colleagues report in the July Animal Behaviour.
The preference develops from sight alone, Dickel says. The researchers kept the crabs in containers that prevented crab scents from getting into the water with the eggs.
Earlier work by the cuttlefish team showed that within a few hours of hatching, the babies need only one good look at crabs to develop a preference for them. Now the window of learning seems to be open even before hatching, Dickel says.
Other research teams have demonstrated that embryo