Everything I Know About Change I Learned From The Giant Mud Crab

Everything I Know About Change I Learned From The Giant Mud Crab

Ecdysis is the scientific term to describe the process of shedding old skin. Snakes, insects, and even crabs do it. If you’ve ever eaten crab, you know that the meat is encased in a small armored shell. This is the part they shed.

In the days leading up to the molt, enzymes cause the upper and lower layers of the crab’s shell to soften and separate. This allows room for water to flood the shell. Its body expands. The actual molting process can take several hours with a day or two post-molt period spent healing and hardening again.

I became intrigued with crab molting and took to the internet to learn more. In one video, you can see a Giant Mud Crab (Scylla serrata) pull itself from its carapace, like a hand emerging from a glove. The hard exoskeleton slices open along the long rear edge. Bulging paper body emerges first. Legs and arms follow, tumbling awkwardly nearby.

There now appear to be two crabs. The soft, freshly molted one, and its hardened hollow twin. A reminder of the body it outgrew. I imagine all of the hollow crab bodies rising to the top of all the oceans. A sea of floating specters.

I call a friend who is a biologist. She also happens to own a leopard spotted gecko, another species that goes through ecdysis. When I inquired about the molting process, she said, “Why the hell are you asking?"

“Because I think I relate.”

“Well crabs have to go through ecdysis. Which is different from snakes and geckos, where the process is healthy and normal, but sometimes doesn’t happen. Crabs physically outgrow their shell. The molt is inevitable.”


Humans, of course, don’t go through ecdysis like crabs or snakes. Our growth is processed internally, with maybe slight external manifestations. I’m not sure if this makes the process better or worse. Maybe I’d prefer everyone to see my skin actually slough off, just so they’d leave me alone until I’m new and shiny again.

I watch videos of molting crabs, crickets, lobsters, and tarantulas. In all of them I feel a moment of panic. Are they ok? It looks painful at worst and extremely uncomfortable at best. I root for them, knowing that if any body part gets stuck they will die.

Reading more about our friend the Giant Mud Crab I learn that during the molt, when the crab is most soft and vulnerable, other hard-shelled crabs will sometimes attack and devour them. Cannibalistic crabs. Who knew?

But this is the exciting part, after ridding itself of its too-small skin, the new body will expand, rapidly, making room for future growth. It’s also a fresh start. Opportunity to grow a new shell free of parasites and barnacles.

A crab may molt 20 times depending on its lifespan. I take note. Exoskeletons of previous selves float to the surface. For once I entertain them, diving headfirst into the inevitable.