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Aging cuttlefish can remember what they had for dinner last week

cuttlefishAlex Schnell/University of Cambridge/PA Wire

Cuttlefish have a brilliant memory, whatever age they are.

The invertebrates can remember what, where and when specific events happened right until their last few days of life, a new study has found.

Researchers suggest that this is the first evidence of an animal whose memory of specific events does not decline as they get older.

The study gave 24 cuttlefish memory tests, half of them were 10-12 months old - not quite adult - and the other half 24 months which is the same to humans in their 90s.

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The cuttlefish memory test

  • Cuttlefish were trained to go to a location in their tank marked with a black and white flag

  • They were taught that two of their regular foods were on offer at certain flag-marked locations

  • At one spot, the flag was waved and they were offered a piece of king prawn, a meal they aren't too keen on

  • Every three hours, for four weeks, live grass shrimp - which they like more - was offered at a different spot with another flag

  • The two feeding locations were different each day to make sure the fish weren't learning a pattern

  • The animals watched to see which food appeared first and they could then work out which feeding spot was best each time a flag was waved

Dr Alexandra Schnell, of the University of Cambridge and author of the paper, said: "Cuttlefish can remember what they ate, where and when, and use this to guide their feeding decisions in the future.

"What's surprising is that they don't lose this ability with age, despite showing other signs of ageing like loss of muscle function and appetite."

Humans slowly lose the ability to remember things, that happened at particular times, like what they had for dinner last week, as they get older.

This is called episodic memory and its decline is thought to be due to part of the brain that does this - called the hippocampus - gradually getting weaker over time.

However cuttlefish brains are different and they do not have a hippocampus.

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The part of the brain associated with learning and memory in the cuttlefish, called the vertical lobe, does not decline until the last few days of the animal's life.

Researchers think this explains why their episodic memory is not affected by age.

Dr Schnell said: "The old cuttlefish were just as good as the younger ones in the memory task - in fact, many of the older ones did better in the test phase."

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