Details of Horseshoe Development

Eggs to Hatching Out
The first 14 days of embryonic development

Getting Larger
Molting: how horseshoe crabs molt to increase their size

Lifecycle of the Horseshoe Crab: An Overview

Scroll over the timeline below for a quick look at the horseshoe crabs's life stages:

Growing Up

Juvenile horseshoe crabs generally spend their first and second summer on the intertidal flats — feeding before the daytime low tide and burrowing in the sand for the rest of the day. As they grow, young crabs move away from the shoal water “nursery” into deeper water.

For the horseshoe crab to grow larger, it must molt and shed its shell. By the end of its first year, the crab will have molted several times, but will still be small — about 1/2" wide. By year three or four, it will shed its shell only once a year, sometime during July or August.