Embryonic Learning

Embryonic learning can be important (apparently) for species that are on their own once they hatch from the egg. Hatchlings of many species get help with protection, feeding and other life lessons from one or both parents, but this is not always the case.

Newly hatched turtles have to make a dash for the sea and learn on the fly. Cuttlefish hatchlings are already in the sea, but they too are on their own. Romagny et al decided to document the perception and learning of cuttlefish embryos in the latter stages of development (1,2). They have lots of stages, but stages 23, 25 and 30 were chosen for them to sit their tests.

Once they get big enough to flex their mantles, they are showing their ability to respond. They had to be taken out of their protected egg cases for their test program. They were exposed to the fishy smell of sea bass. That startled them and they flexed in consternation as sea bass like to lunch on young, succulent cuttlefish. They also weren’t very keen on being poked and prodded with a needle, blunt, of course, but nevertheless they flexed away.

Later on, they were exposed to light when their visuals were operational, and that too startled them into flexing. At stage 30, light was becoming a little boring and they would only bother flexing for a short while before quitting.

The team wondered if they were just getting tired from overwork so they decided on the willing horse solution – they spurred them on with a prod from their needle. That got them working again. They weren’t tired. They had learned that they didn’t need to respond to the light as nothing else happened. The spur, though, reminded them that they were supposed to be performing for the team of researchers and they went back to work with a will.

So it seems that it never to early to learn which side of your bread is buttered and to mind your p’s and q’s.

  1. http://jeb.biologists.org/content/215/23/4125.abstract
  2. http://jeb.biologists.org/content/215/23/i.2.full

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