Stories tagged cuttlefish

Cuttlefish eye: The highly developed organ can take in information during its embryonic stage.
Courtesy sophmattgunnerCuttlefish embryos peering out from inside their eggs are able to identify their prey, and remember them after they’ve hatched, according to a research team at the University of Caen Basse-Normandy, France that has documented the remarkable feat.

Cuttlefish are cephalopods related to squid and octopus, and their eyes are considered some of the most developed in the animal kingdom.

The research team led by Ludovic Dickel harvested wild cuttlefish eggs and placed them inside a series of tanks containing sea water. Cuttlefish eggs are translucent but enclosed in a black ink in their early stages. But this protective cover clears eventually as the eggs develop. Some of the eggs were set up in plain view of crabs, a favorite prey of adult cuttlefish. The crabs were partitioned in glass compartments with varying degrees of clarity, and the embryos could neither smell nor hear them, only see them. Other eggs were placed in tanks without any exposure to crabs.

Cuttlefish on the prowl
Courtesy richard lingAfter hatching, the infant cuttlefish were removed immediately away from the crabs before the hatchlings had a chance to see them, and allowed to develop in isolation. After seven days, they were set free inside tanks containing both crab and shrimp, another favorite cuttlefish food.

Remarkably the cuttlefish that had been exposed as embryos to the crabs preferred to eat them. And those with the clearest view of the crabs, had the greatest taste for them. Those with no prior view of the crabs preferred the shrimp.

Other animals have been known to pick up chemical and audio cues during the embryonic stage, but this is the first evidence of visual learning by embryos. The study’s results appear in the journal Animal Behaviour.

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Tags : animal behavior, cuttlefish, cephalopods, animals, embryos

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