About Horseshoe Crabs

The Atlantic horseshoe crab, Limulus polyphemus, is a fascinating species that is important both ecologically and medically.  They are distributed from the Gulf of Mexico to Maine. In late spring and summer, adults enter coastal lagoons like the Maryland Coastal Bays to spawn on protected shorelines. Their eggs are an important food source for migratory birds such as the red knot.

Horseshoe crabs are commercially harvested for two purposes: 1) they are used as bait in the conch fishery; 2) their blood is used to detect endotoxins produced by bacterial contamination in pharmaceuticals and medical devices. 

Historically, declines in the abundance of horseshoe crabs in the Mid-Atlantic population have been attributed to unsustainable harvest by the bait fishery (Smith et al. 2017). More recently, the population has remained stable, likely due to regulatory limits placed on bait harvest. 

Despite recent success of fishery regulation, this species remains susceptible to impacts by overharvest, climate change, and habitat loss. Given this species' important role in protecting human health, it is vital to clearly understand its biology in order to inform sound management decisions. Our goal with this project is to improve that understanding.

Links to more information about horseshoe crabs: 

Horseshoe crab anatomy

Horseshoe crab biology

Fishery and stock assessment

Reference: 

Smith, D.R., Brockmann, H., Beekey, M.A. et al. Conservation status of the American horseshoe crab, (Limulus polyphemus): a regional assessment. Rev Fish Biol Fisheries 27, 135–175 (2017). https://doi.org/10.1007/s11160-016-9461-y