Cuttlefish go light on lunch when there's shrimp for dinner
A team of scientists led by the University of Cambridge has found that when cuttlefish know they're getting shrimp for dinner, they'll only have a light lunch of crabs. This ability to anticipate their favorite food is an indication of the cephalopod's complex brain and cognitive abilities.
The European common cuttlefish, Sepia Officinalis, may not know much about food, but it does know what it likes, and it likes shrimp. It also has a relatively complex foraging strategy and can switch from an opportunistic strategy where it will eat anything that comes along, to a selective strategy, where it can seek out or wait for a preferred food based on learned behavior.
In order to learn more about this, the Cambridge team fed cuttlefish in different ways. In one experiment, the tentacled mollusks were fed crabs during the day and then shrimp in the evening on a regular basis. In a second experiment, they were fed crab during the day and randomly fed shrimp in the evening. This way, in the first experiment, the cuttlefish could predict that they would be fed shrimp, but couldn't when the special appeared at random in the second.
According to the team, when the cuttlefish knew they were getting shrimp for dinner, they wouldn't eat many crabs during the day, but when they couldn't anticipate their preferred meal, they filled up on crab. Not only that, but when the feeding routines were changed, the cuttlefish quickly learned and adapted. In this way, the animals could make sure they were well-fed, yet not miss out on a treat if they knew it was on the menu.
Just to make sure the cuttlefish were shrimp aficionados, 29 were given a choice of crab and shrimp five times a day for five days by placing each food item an equal distance from the diner, who, it turns out, always went for the shrimp entree.
"This flexible foraging strategy shows that cuttlefish can adapt quickly to changes in their environment using previous experience," says team leader Nicola Clayton in the University of Cambridge’s Department of Psychology. "This discovery could provide a valuable insight into the evolutionary origins of such complex cognitive ability."
The study is published in the Biology Letters.
Source: University of Cambridge