Hundreds of horseshoe crabs invaded the subtle slopes of Plumb Beach’s shoreline in their own sex-fueled, prehistoric rendition of the Allied invasion of Normandy last week, as horseshoe crab mating season kicked off on Thursday, April 25.
The National Parks Service snapped the photo above of some of the crabs getting down and dirty. The animals have been taking to soft-sloped beaches of the mid-Atlantic during the spring’s new and full moons for 400 million years, one of the few living species known to predate the earliest dinosaurs. Female crabs come ashore and deposit up to 20,000 eggs each, followed by a handful of males clinging to their tails and fertilizing the eggs in their wake.
The crabs come up in late April, May, and throughout June – just before high tide or long after sunset – during full and new moons. You can see them around the following dates:
- Thursday, April 25, 2013 (Full Moon)
- Friday, May 10 (New Moon)
- Saturday, May 25 (Full Moon)
- Saturday, June 8 (New Moon)
- Sunday, June 23 (Full Moon)
- Saturday. July 6 (New Moon)
- Monday, July 22 (Full Moon)
- Wednesday, August 7 (New Moon)
- Wednesday, August 21 (Full Moon)
Also, check out this video Sheepshead Bites made back in 2010, when the American Littoral Society’s Don Riepe showed us around the beach and the horseshoe crab’s mating practices. Yes, it has bifurcated penises.