MYSTIC, Conn. (WTNH) — People at Mystic Aquarium know a lot about horseshoe crabs but not everyone does. A bill that got unanimous support by state representatives aims to protect the ancient animal.

“They’ve been around longer than dinosaurs and they’ve always looked the same,” said MaryEllen Mateleska, director of education and conservation at Mystic Aquarium.

They have survived more than 400 million years but now the population is on the decline. CT House Bill 5140 looks to stop legal and illegal harvesting which can kill 50,000 horseshoe crabs in Connecticut alone each year.

Not only do horseshoe crabs benefit, but migrating shore birds which survive on many of their eggs. They also have a biomedical benefit.

“One horseshoe crab with one quart or one pint of blood can save tens of thousands of people,” Mateleska said.

That is because a horseshoe crab’s blood produces an antibody which will protect it from any ailment, so when a new vaccine comes out, it is often tested on that blood.

“If you see that clotting, we know it’s not safe for human use,” Mateleska said.

“If we lose a species like that to extinction, what other medical marvel could we derive from this,” said Sen. Tony Hwang, (R) Fairfield.

State senators will now consider the bill, which carries a $25 penalty per violation, but raises a lot of awareness about the living fossils.

“Who would have ever thought 10, 15 years ago that the blood of the horseshoe crab could provide medical miracles in saving lives,” Hwang said.

If you see a horseshoe crab’s exoskeleton on the beach, you can take it. If you look closely and see a split in the underside back of the shell, that’s from where the horseshoe crab literally walked right out of its exoskeleton and a new one will harden.

Otherwise, if you see a live horseshoe crab, you should just leave it alone, unless it is upside down.

“Flipping them over can save a life,” Mateleska said.

The state Senate is expected to vote on the bill before the legislative session ends at midnight on May 4.