While it may seem peculiar, horseshoe crabs are changing the game of medical research, as scientists have discovered a key protein found in their blood.

Workers at the Wako Chemicals facility in Cape Charles, Va., as well as three other sites on the East Coast, regularly capture horseshoe crabs to extract their pale blue blood to use in testing, Eastern Shore News reported.

"Basically, anything that comes into contact with the blood is tested using LAL," or "litmulus amebocyte lysate," said site manager Christina Lecker.

Horseshoe crab blood holds a protein that protects the animal from impurities, and is used by researchers when testing medical instruments, implants and pharmaceuticals.

This ability, coupled with the fact that these marine creatures lack an immune system, make horseshow crabs well-equipped for surviving in bacteria-saturated environments, especially in the near-shore ocean habitat occupied during spawning season and as juveniles.

Around 611,800 crabs were taken in 2012 for biomedical purposes, according to data from the Atlantic States Marine Fisheries Commission. Captured crabs are then brought to a lab where about one-third of their blood is extracted in about 30 minutes. The blood from two males can fill one specimen bottle, whereas larger females can usually fill a bottle themselves.

But don't worry, these horseshoe crabs are taken from coastal waters under a biomedical permit and returned to their habitat after the blood is drawn.

"The crabs are returned within 48 hours," said Lecker, via Eastern Shore News.

So that crabs aren't extracted for their blood again - at least until they have had time to molt and gain new, unmarked shells - scientists punch a small hole in their shells to serve as a marker.

Most patients likely have no idea how much they owe to the horseshoe crabs, Lecker told Eastern Shore News.

"They have no idea how everything gets passed through the horseshoe crab test," she said.

Horseshow crabs (Limulus polyphemus) are found in the Atlantic Ocean along the North American coastline, according to the National Wildlife Federation. The two other kinds in existence inhabit waters in the Indian Ocean and in the Pacific Ocean along the coast of Asia. They can be about 18-19 inches from head to tail, live over 20 years of age in the wild, and typically feast on worms and clams.