…is a species of horseshoe crab found throughout Southeast Asia and India and is the only member of the genus Carcinoscorpius. Like other horseshoe crabs the mangrove horseshoe crab is primarily nocturnal and feeds on benthic invertebrates like insect larvae, worms, and crustaceans, it grinds these food items up with its bristly legs and moves them into its chelicerae to be ingested. Like their Atlantic cousins mangrove horseshoe crabs will congregate in the shallows during the spring for mating (although they don’t do it in the same force.)
Region: Are most commonly found in the Gulf of Mexico and along the northern Atlantic coast of North America
Risk of Extinction: Near Threatened
More Info: It’s a living fossil. The blood of horseshoe crabs contains the copper-containing protein hemocyanin at concentrations of about 50 g per liter. These creatures do not have hemoglobin (iron-containing protein), which is the basis of oxygen transport in vertebrates. The blood of horseshoe crabs contains one type of blood cell, the amebocytes. These play an important role in the defense against pathogens. Amebocytes contain granules with a clotting factor known as coagulogen; this is released outside the cell when bacterial endotoxin is encountered. The resulting coagulation is thought to contain bacterial infections in the animal’s semiclosed circulatory system.
FINALLY finished this up! While in Rhode Island I found a tiny travel-sized horseshoe crab prosoma, probably from a lil crab molting. I didn’t take any ‘before’ pictures, but it was covered in encrusting algae and full of sand. I managed to get it back to California in one piece and let it soak in a bucket of diluted bleach all day. I scrubbed it with some wire brushes to get the last bits of algae off, and sprayed it with lacquer to make it shiny and strong. It’s probably my favorite thing in my dead things collection right now; all the spines are intact, you can see the facets of the compound eyes, as well as the tiny holes where the median eyes were.
A, Anterior view of cross section through cephalothorax showing arrangement of extrinsic muscles of the third leg. B, Dorsal view showing approximate locations of ‘‘muscular somites’’ composing the carapace and tergum.