JACKSONVILLE, Fla. — If you have received a vaccine, undergone cancer treatment, or used weight loss medication in recent years, you owe some gratitude to the horseshoe crab.

These creatures, often referred to as living fossils, predate the dinosaurs and play a crucial role in medical advancements.

Despite their ancient lineage and significant contribution to modern medicine, horseshoe crabs are facing a potential threat of extinction.

Having thrived for 450 million years, the call to protect these remarkable animals is becoming increasingly urgent.

Now, a group is suing the federal government, calling for the horseshoe crab to be placed on the endangered species list.

Horseshoe crabs occur in every single coastal county in Florida. They are the ancient-looking, hard-shelled animals with quirky traits.

“Their mouth is in between their legs,” Dr. Savanna Barry of the University of Florida said, “and eyes on the bottom of their body.”

And their blood is blue! It’s also a lifesaver.

“For decades, horseshoe crabs have saved countless humans lives,” Will Harlan said.  He is the Senior Scientist for the Center for Biological Diversity.

Their blood is used to test the safety of vaccines and injectables.

“Whether it’s for obesity or for cancer treatments, so they are really important in protecting human health,” Harlan noted.

He cites research which shows the harvesting of horseshoe crabs for biomedical testing has led to a sharp decline in the animals populations across the United States.

“Their numbers have absolutely crashed since 2000. They’ve dropped off a cliff face. A 70% decline in horseshoe crabs since 2000,” Harlan said. 

So the Center for Biological Diversity has asked and is now suing the federal government, wanting the animal listed as endangered or at least threatened, thus ensuring its protection. 

Dr. Savanna Barry helps lead the citizen science project that counts and tags horseshoe crabs in the Sunshine State. She could not comment on the lawsuit, but she says it’s not clear if the horseshoe population is declining in Florida specifically.

“We don’t have enough data points to calculate a trend yet,” Barry noted. 

When biomedical companies catch the horseshoe crabs, they’re taken to labs and bled. Some survive the ordeal. Some do not.

Harlan said, the horseshoe crabs are “stabbed with a needle in the heart and drained of much of their blood.”

“It’s quite stressful because they do lose about a third to half of their blood during that process,” Barry said. 

“It’s estimated 30 percent of them die in the process,” Harlan added. The rest are released back to the wild, often in a weakened state.

“The good news is that we don’t need horseshoe crab blood anymore,” Harlan said. “There are synthetic alternatives that are already being used.”

Pharmaceutical companies are already using these alternatives to horseshoe crab blood, but not entirely.

Harlan feels if the United States protected the crabs, more biomedical companies would make a faster switch to synthetic options.

“That synthetic alternative is more reliable, safer, and more cost-effective, and is more sustainable long term,” he said. 

Recently, he noted that Congress instructed the FDA to update what it tells pharmaceutical companies, that the synthetic blood is just as impactful, effective, and safe as the blood from horseshoe crabs. This may spur companies to make the switch.