2025 Horseshoe Crab Reproduction Research

Horseshoe crabs in marsh.
Photo by SCDNR.

When water temperatures rise to 60-degrees and level off after the last cold snaps of winter, the coastline welcomes horseshoe crabs for their annual spawn. From late March until June is when these hard-shelled arthropods, scientific name Limulus Polyphemus, come crawling onto the beach. However, new research is observing that horseshoe crabs are nesting in the salt marsh too, piling their eggs into pluff mud where they are seemingly safer from predators. 

 

Dr. Daniel Sasson is an assistant marine scientist with SCDNR, who studies horseshoe crabs. “There are fossil remains of horseshoe crabs from 120 million years ago, that show the crabs today are similar to their ancestors,” said Sasson. “Despite their name they are not actually crabs and are more closely related to spiders and scorpions. Some folks at SCDNR had observed horseshoe crabs in the spartina marsh prior to my arrival in 2020, and they had some initial success at locating eggs in the mud.”

Horseshoe crab eggs.
Photo by SCDNR.

To view the feature article in the Post and Courier click on Tideline.

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