By Kelsey Arenson, Jamie Finnical, and Kamilla S. Raising Our Horseshoe Crab By Kelsey Arenson, Jamie Finnical, and Kamilla S.

The Horseshoe Crab History Scientific Name: Limulus Polyphemus Is an arthropod- an invertebrate with an exoskeleton, that has a segmented body and jointed appendages Evolved in the shallow seas of the Paleozoic era, nearly 248-520 million years ago. The oldest fossils found have been dated at 360 million years ago. This is around 100 million years before dinosaurs evolved. During the time of major extinction of the dinosaurs and half the earth’s marine animals, the horseshoe crab survived.

Anatomy Prosoma Opisthosoma Telson

Anatomy The crab is divided into three sections that compose the exoskeleton, which is shed periodically as the crab grows Prosoma- the largest section of the horseshoe crab. Gives the crab its name, for it looks like a horseshoe from a top view. The crab’s ten eyes are found along this section. Opisthosoma- the abdomen. The center section of the shell that attaches to the prosoma using a hinge. Telson- the tail. Is used to steer while swimming and right itself if it turns over in a tidal zone. Six legs on each side of the prosoma Five pairs of gills

Life Cycle Egg Juvenile Larvae Adult

Life Cycle Horseshoe crabs lay their eggs on beaches A female can lay 4000 eggs or more at a time An egg takes 6 days to hatch As crabs reach their juvenile stage, they molt multiple times as they grow. They molt many times for the first 2-3 years, but molt only once a year until they reach full maturity at 9-11 years. Scientists are not sure how long they live in the wild, but in captivity they can live for 20-40 years.

Diet Clams Brine Shrimp Worms

How do the crabs affect the environment? Most importantly, shorebirds are incredibly dependent on horseshoe crabs for food. Since one horseshoe crab can lay 4000 eggs at a time, it can feed many shorebirds throughout it’s lifespan. If the crab population decreases, then the shorebird population decreases as well.

What does our project do for the environment? Although only one horseshoe crab survived to be released, this one crab will produce many offspring and feed many shorebirds. The fact that 1 out of 3 horseshoe crabs survived is a lesson that these crabs are sensitive to their water quality. This teaches us that the proper conditions need to be maintained in the crab’s habitats in order for them to survive.