Saturday, August 28, 2010

Eureka, a horseshoe crab!

Guénaëlle Rubin, Delaware Expedition

Eureka, a horseshoe crab! Dave is carefully holding the one single horseshoe crab found in the weir net. (Learn more about weir nets and why we're in Delaware observing the haul back in this previous blog entry!) Although horseshoe crabs have a menacing appearance, they are quite harmless. Horseshoe crabs do not sting, pinch or bite.

This was the biggest horseshoe crab that I had ever seen! It was definitely a female, since female horseshoe crabs are significantly larger than males. This is about the time of year when horseshoe crabs finish laying their eggs ashore, so the fishermen were not surprised to see one in their nets. Horseshoe crabs can lay as many as 120,000 eggs in one season! Although that sounds like an awful lot, many of the eggs are eaten by migratory shore birds that pass over the Delaware Bay. Red knot birds, for example, rely on horseshoe crab eggs for food to survive their long and arduous migration of 9,000+ miles.

Horseshoe crabs are life-savers for humans too. Almost all medical injections such as vaccines are tested using horseshoe crab blood since their blood contains a compound called Limulus amoebocyte lysate (LAL) that detects the presence of endotoxins.

You can see horseshoe crabs at the Aquarium at the Edge of the Sea exhibit. Come by sometime to see these amazing animals in person!

1 comment:

  1. When I was down at the Jersey shore back in mid-June, we were sitting on the beach and all of a sudden this huge wave crashed down and left this GIANT horseshoe crab sitting on the sand. A few minutes later, another wave took her away. But she was HUGE - Slightly bigger than the one in this picture! It was so cool!