Horseshoe Crab Anatomy

For ecologists the horseshoe is an important creature a vastly adaptable generalist that predates most species on the planet with a lifecyle that is interlocked with other animals. The horseshoe uses the first pair the chelicera for placing food in its mouth.

Horseshoe Crabs Everything You Need To Know About This Species

The atlantic horseshoe crab limulus polyphemus also known as the american horseshoe crab is a species of marine and brackish chelicerate arthropod.

Horseshoe crab anatomy. A quick glance at the horseshoe will show the crabs two compound lateral eyes unusual because no other living chelicerate possesses compound eyes. These are the first ambulatory legs. Externally horseshoe crabs can be divided into three sections.

A look at the underside of the horseshoe reveals six paired appendages. There are three divisions to the body of the horseshoe crab. Horseshoe crabs are generally predators of different species of annelids molluscs as well as of other groups of benthic invertebrates.

However they can also feed on algae. The next pair of appendages are the pedipalps. These are sometimes referred to as the cephalothorax the abdomen and the tail.

These are used primarily for finding mates but the horseshoe has many more light sensing organs. The horseshoe crab for many the horseshoe crab is a childhood acquaintance first introduced by a fierce looking shell on a sandy beach. It has two compound lateral eyes each composed of about 1000 ommatidia plus a pair of median eyes that are able to detect both visible light and ultraviolet light a single endoparietal eye and a pair of rudimentary lateral eyes on the top.

These are sometimes referred to as the cephalothorax the abdomen and the tail. In the adult male the tarsus of these legs are modified as a grasping appendage allowing males to clasp the female during spawning. The prosoma the opisthosoma and the telson.

The horseshoe crab has been on earth for 350 million years. Horseshoe crabs have a total of 10 eyes used for finding mates and sensing light. An ancient and complex anatomy hides within its domed shell.

American horseshoe crab telson. You can also remember them as the cephalothorax which is a fused head and thorax region the abdomen and the tail respectively. The horseshoe crab uses its telson to steer and right itself if it becomes inverted in.

A horseshoe crab absorbs oxygen from the water using gills that are divided into. The prosoma the front most section the opisthosoma the mid region and the telson that sword like tail. Despite their name horseshoe crabs are more closely related to spiders ticks and scorpions than to crabs.

The entire body of the horseshoe crab is protected by a hard carapace.

Anatomy