Photo a Day: Day 43. Here are some mating horseshoe crabs! The male is the smaller one on the back/ top, and the female is the larger crab in the front/ bottom. The horseshoe crab species is about 450 million years old, making them one of the oldest species of animal on earth.
While connected, the female will dig herself into the sand and lay up to 140,000 eggs over several locations.