What is modified leg in crayfish?

Anaplastic ferns have a modified leg, the "stegosoma. " In crayfish, the leg is shaped like a horseshoe and, like a horseshoe, has some spines on it. Anaplastic ferns have this modified stegosoma because it allows them to move freely.

When they do, they have an advantage in a fight: it forces them to remain in one place, and allow others to do the same. A crayfish can also break the fern's modified leg, which allows it to escape.

Some crayfish also can use the modified leg to kill smaller crayfish while it is trapped.