Ever find an empty crab shell on the beach? Video shows how it ended up that way
A dramatic video of a crab shedding its shell was posted on Facebook Wednesday by the South Carolina Department of Natural Resources, which called the process “pretty amazing.”
The timelapse video shows the process called molting. That is when an animal, a blue crab in this case, will “cast or shed” its shell “that will be replaced by a new growth,” according to Dictionary.com.
According to SC DNR, blue crabs, like the one in the video, are invertebrates, which “wear their skeletons on the outside.” That skeleton, a shell in this instance, must be replaced during the molt for a new one, per SC DNR’s Facebook post.
Part of the growing process for young crabs, the video shows how a crab molts. SC DNR said the blue crab “absorbs extra seawater, cracks open the back of its shell, and slowly wriggles out, growing about a third in size into a shiny, new soft-shell crab.”
But the process is not over after the crab sheds its old shell.
The new shell must harden over the course of a few days, the post says. Because of that, “newly molted crabs hunker down in a safe place to avoid becoming a soft-shell snack,” SC DNR said of the process that will repeat over and over 18 times before the crab matures.
That means it happens about once every two months, since the life span of a blue crab is three years, Coastal Living reported.
SC DNR’s video came from one of its educational aquarium tanks, according to the Facebook post.
As of 10 p.m. Wednesday, the video on SC DNR’s Facebook page had been viewed more than 5,400 times.
While some of the people who commented on the post marveled at the process and were educated by the video, one made a joke, writing “Soft shell snack!”
While wildly popular in South Carolina, where they can be found along the coast in the Low Country, as well as North Carolina, blue crabs range from Texas to Massachusetts, according to SC DNR.
This story was originally published February 6, 2019 at 10:19 PM with the headline "Ever find an empty crab shell on the beach? Video shows how it ended up that way."
