Chapter 27, Problem 14STP

Summary Introduction

To write: The reason horseshoe crabs are more closely related to spiders than to regular crabs and lobsters.

Introduction: The horseshoe crab is not an actual crab. Moreover, they are far closer to spiders and arachnids than crabs or lobsters. There are four horseshoe crab species. Only one genus can be found in the Atlantic and Gulf coasts of North America; Limulus polyphemus, is present between Maine and Mexico, and the other three species of horseshoe crabs can be found in South-East Asia.

Explanation of Solution

Horseshoe crabs are more closely related to spiders, ticks, and scorpions. They have a rigid shell or exoskeleton, joined wings, and a segmented body like arthropods. Their legs are attached to their mouths. Though horseshoe crabs are closely related to the spiders, they have a different class. They differ from the original crabs as they do not possess mandibles that grind food and antennae, like the crabs.

Conclusion

Thus, horseshoe crabs are more closely related to spiders than to regular crabs and lobsters.