George Jacob is the President & CEO of Bay Ecotarium / Smithsonian Affiliated San Francisco Aquarium and Sea Lion Center celebrating its 25th Anniversary of ocean/ watershed conservation from Sierra to the Sea.
Oceans hold unexplored secrets and solutions to many of our problems. Horseshoe Crabs have remained unchanged for over 445 million years from the Ordovician period before the age of dinosaurs, and are often called living fossils. Protected by a hard carapace shell, these primitive creatures are designed to survive and have two compound lateral eyes, a pair of median eyes capable of detecting both visible light and ultraviolet light, a single endoparietal eye, and two rudimentary lateral eyes on the top activated just before the embryo hatches. As if that was not enough, it owns a pair of ventral eyes located near the mouth in addition to a cluster of photoreceptors on the telson or tail like structure. Horseshoe crabs have the largest rods and cones of any known animal, about 100 times the size of humans, despite the relatively poor eyesight. With a life span of up to 20 years, these toothless animals feed on small clams, crustaceans, algae and worms.
Covid 19 vaccines will rely on the mighty 9 eyed Horseshoe Crab’s ancient immune system for billions of doses in pharmaceutical production down the line. Their milky blue blood laced with copper in their oxygen-transporting proteins is the only known natural source of limulus amebocyte lysate (LAL) that can detect contaminant endotoxins.
Pharmaceutical companies puncture the cells in the Horseshoe Crab’s blue blood to release a chemical called coagulogen. These elements can detect a dangerous bacterial endotoxin even at the miniscule concentration levels of one part per trillion and contain it by forming a gel around it. Discovered back in 1956 by Fred Bang, these gels are capable of trapping the bacterial endotoxins for weeks at room temperature in a cocoon, without killing it. Since 1970, the FDA requires every drug to be tested using LAL or Limulus Amebocyte Lysate named after the humble Horseshoe Crab or Limulus Polyphemus. The LAL test applications include quality assurance for intravenous drugs, insulin, vaccines and implantable medical devices like heart valves and orthopedic inserts.
Prior to this discovery, scientists had no way of knowing if a particular vaccine was safe to administer. Like E. Coli or Salmonella, they had to inject the vaccine in a significantly large number of rabbits and wait to observe the symptoms they developed. The pharmaceutical industry captures over 600,000 crabs each year to drain 30% of its milky blue blood that retails for a whopping $60,000 per gallon!
After the harvest, they are dropped back in the ocean. It is estimated that nearly 30% of them will not survive in the wild and others might feel weak and disoriented for a few weeks after being released in the ocean. Shoreline urbanization impacts their breeding habits and habitats. Nearly a million crabs are harvested for eel and fish baits in the United States alone, while consumption of their eggs in parts of south-east Asia continues.