Commercial Fisheries News - August 1999

Lobster shedding in a nutshell

The larger the lobster, the longer it takes it to shed. A legally sized lobster spends about 1/2-hour escaping from its old shell once it has rolled over on its side.

To begin shedding, the carapace (part of shell covering the body) lifts up away from the tail. The lobster raises the carapace by swallowing water. Then, the whitish colored membrane between the body and tail bursts, the fluid escapes, and the lobster rolls over on its side.

Lobsters shed the body and head first. The gills can be seen beneath the carapace while the lobster molts the lining of its gills (fuzzy stuff attached to legs).

Next, the eyes pop out under the old shell. By now you can see the new shell covering the body. Throughout this time the lobster pulls and pulls until it finally frees the bulky claw meat from the narrow joints.

Once the claws are shed, the entire lobster is freed with the flip of the tail. An intact shell now lies beside the helpless rag.

For the next 1/2-hour, the lobster flops around unable to support itself on its legs. The claws are shriveled up and the antennae fall to the bottom. The lobster swells up again with water to build itself a hydrostatic skeleton. Then, if it is a sexually mature female, it walks toward its mate and copulates. If it is a male, it begins to eat its old shell.

Gradually, the claws swell up to fill in the new shell. In a few hours, the new shell grows to its full size.

If you catch a lobster during the act of escaping from the shell:

Ask the Lobster Doc