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October 19, 2017

Red crabs on Christmas Island in the Indian Ocean

Red crabs on Christmas Island in the Indian Ocean.

More about this image
Tens of millions of red crabs inhabit Christmas Island in the Indian Ocean. All the crabs live in the middle of the island and are fully terrestrial, but their eggs have to develop in the ocean. In order for the crabs to reproduce, that is, to actually have eggs that develop into offspring, they have to migrate to the beaches and release their eggs in the water. If the crabs don't make the trek to the ocean they will not reproduce that year.

Allison K. Shaw, a Ph.D. student at Princeton University at the time, went to Christmas Island to study the crab migration. Her work was supported by a U.S. National Science Foundation Graduate Research Fellowship (grant DGE 0646086).

Shaw's research was detailed in the National Geographic television program "Great Migrations" in the episode titled "Born to Move." (Date image taken: October-December 2008; date originally posted to NSF Multimedia Gallery: Oct. 19, 2017)

Credit: Allison Shaw, Princeton University

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