Thursday, May 30, 2013

Horseshoe Crabs at Slaughter Beach, DE

On Saturday I met up with a new friend and we drove up to Slaughter Beach in Delaware where we hoped to witness one of the oldest mating rituals on planet Earth, the spawning of the Horseshoe Crab. We left early so we could stop at interesting places on the way and found a really cool junk place near Bridgeville.
We met our group at a park and went for a very unorganized hike first at which my toe argued against doing but I persevered and actually didn't feel too bad afterwards. But we weren't disappointed with the boring hike, we were all anxious for the sun to drop and the tide to come in so we could witness the amazing crab spectacle. They are seen in bigger numbers at high tides and also with a full moon. we were going to have both this evening.
 We saw this poster in the park office and our hopes were high that we'd see as many as shown here.
One poor victim.
Where are they?
We got down on the sand and noticed a few dead crabs upturned along the shore, casualties from the previous high tide's spawning. but as far as live ones were concerned, we couldn't see one. We waited and as the sun went down and the water washed up closer to our feet, they came.
 First we noticed bumps in the water, the odd large lump dotted here and there, but as we got closer we saw that they were the first arrivals, gradually grouping together as more arrived, until after about 30 minutes, the shoreline was a mass of moving crabs. It was an amazing sight. The females are larger than the males as they lay thousands of eggs at a time. She lays them in the wet sand while the males work their way back and forth fertilizing them.
The Horseshoe Crab isn't actually a crab but is more closely related to the spider or scorpions. they have eight eyes, 2 of which are on the top of their shells and long tails which they use as rudders or to flip themselves over when they find themselves upside down. They were doing this quite often with so many of them wriggling around and are very vulnerable and likely to die if they are not righted, so we were constantly helping the flipped ones back onto their feet as we walked up and down the beach. Their shells are like armor casings but not as thick as I had assumed.
We had an amazing time watching these wondrous creatures and loved being part of a ritual that has been going on for millions of years, These crabs have been around more than 200 million years more than the dinosaurs and they certainly have a prehistoric look about them. They've hardly changed in appearance at all.
Eventually we left them to other watchers who had arrived and who immediately set about flipping over the upside down crabs, who were wriggling their legs as if to say, "Hurry up! Over here, I need a hand!" It was going to be a long night for these hardy and voracious arthropods, but after 450 millions years they certainly don't need any rehearsals for their moonlight dance.

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