Baby Horseshoe Crabs

Article and photos by Sara Buck Lane Tybee Island Marine Science Center

While the team at the Tybee Island Marine Science Center spent 2020 hard at work preparing to open their new location on the north end of Tybee Island, they also became parents, parents of tiny horseshoe crabs that is. These undeniably cute Atlantic horseshoe crab babies hatched from peppercorn-sized eggs and were collected by the center’s team on nearby Little Tybee Island during the height of the pandemic. A true reminder that nature waits for nothing, not even a pandemic!

Frequently seen on our beaches during their mating season, Atlantic horseshoe crabs are fascinating creatures that are more closely related to scorpions and spiders than crabs. Chances are, you’ve seen their molts (shed exoskeletons) that commonly wash up onto the beach year-round. Close cousins to the extinct trilobite, horseshoe crabs are a living fossil and have been in the fossil record for 445 million years. They spawn on the beach in the late spring and early summer, with mature females laying five to seven clumps of 2000-4000 eggs in the sand. In one year’s time, females can lay up to 90,000 eggs. And if that isn’t interesting enough, horseshoe crabs have ten eyes! Much of what we know about the function of our own eyes is the result of studies that began in the 1960s on the large, compound eyes of the horseshoe crab. They have also contributed to the medical research community. A substance found in their copper-based blue blood called Limulus Amebocyte Lysate is used to test for bacterial endotoxins in pharmaceuticals and for several bacterial diseases.

Growing up to 24 inches in length, horseshoe crabs have no jaws or teeth but they use the base of their legs to grind up clams. Their predators include alligators, sea turtles and migratory shorebirds. As a matter of fact, migrating shorebirds that leave the tip of South America for their nesting grounds within the Artic Circle perfectly time their migration up the eastern coast of South, Central and North America just as horseshoe crab eggs are maturing into nutrient-rich, fatty nuggets of energy.

These baby horseshoe crabs joined 11 young adults that were already part of the center’s display. The tiny babes will continue to grow at the Tybee Island Marine Science Center and serve as education ambassadors in the center’s coastal gallery. The current center located on the south end of Tybee Island closed midDecember in preparation of the move to the brand-new center located at 37 Meddin Drive on the north end of the island. The new 5,400 square foot space will feature hands on exploration activity, demonstrations, displays, exhibits, films, presentation kiosks and nature-based play sites throughout the facility and grounds. In addition to the interior space, the center will also feature a ground level, open air undercroft which will be used for classes and programs. The new center is scheduled to open in the spring of 2021. For more information on the Tybee Island Marine Science Center, their efforts and to donate to their capital campaign, please visit TybeeIslandMarineScienceCenter.org.