Surviving in an antagonistic environment without a skeleton literally, is a dangerous challenge to life. But, this is what crabs and other animals periodically do to grow larger! — shed their hard shells, or exoskeletons.
But, new research says that they don’t survive in a state as vulnerable as thought. At least one crab species creates an internal so-called ‘skeleton’ made of gas produced from its guts and hence stays adapted to this shading phase.
Jennifer Taylor, a biology doctoral student at the University of North Carolina in Chapel Hill said,
They essentially secrete what looks like a whole [shell] under the old one… They pump themselves up and inflate their gut, and that increased pressure will cause the old outer skeleton to crack, so that the crab can back out of it… In the case of this crab the inflation of the gut is increasing the pressure of body fluids throughout the whole animal, making it more rigid. That provides something for muscles to contract against.