Pelagic Larval Stage

September 3, 2011

I love this video of baby giant octopi (5mm long) at the Vancouver Aquarium:

The CBC has an article about the event  and states that it is unlikely that any of the 300 hatchlings will survive:

Chances of survival are very low because giant Pacific octopuses have a seven to ten month long pelagic larval stage. To further our knowledge of octopus reproduction, we will attempt to feed and maintain some the larvae for as long as possible.

Pelagic means open water, think deep blue (i.e. no bottom) vs. a reef. I first read about pelagic larval stages in the book Reef Fish Behavior and was blown away at how profoundly different this mechanism is compared to anything I’m used to in the animal world.

I have a built-in assumption that parents and offspring share the same habitat (think Finding Nemo). With most reef fish, not only do the babies never see their parents again, they most likely will never see the same reef their parents inhabit. There is no nepotism on the reef.

How cool is that? And the giant Pacific octopus larvae can’t survive without this stage, or at least no one has figured out what is missing in an aquarium environment (yet).