A Gripping Tale: Strong Embraces and Hangers On

(Memorial Day Arthropod Voyeurism Part 1)

[the button I had made for all 10 of us
in "The Limulus Gang"]

During the horseshoe crabs’ lustful storming of the Delaware beaches during May’s high tides, it’s all about sex—but not always in the same way.

For horseshoe crabs, fertilization is external but still close-up and personal—none of that soulless, faceless broadcast spawning for these invertebrates, thank you very much. Instead, a male grips a female—either before or soon after she’s crawled on shore—and, while she releases eggs into a nest she’s dug in the wet sand at the water’s edge, he releases sperm over them.

All well and good, and very romantic—a midnight embrace on the starlit shore, the waves murmuring sweet nothings—but that’s not the only kind of hanky-panky going on. Some males don’t compete to grip females; instead, they hover around already mated pairs, clustering close, and also release sperm over the female’s eggs.

These males are called “satellite males,” and—although the number of eggs they fertilize varies a lot—they still end up with enough offspring from their sideways encounters that their tactic is considered a legitimate alternate mating strategy.

And it really is a separate strategy, not just a back-up plan for those males too slow or shy to find a solo female; I’ll have to check my sources to provide you with citations, but I’m pretty sure researchers have found that the same males remain either satellites or grippers (not the technical term) at different times and under different circumstances.

You have to admit, this adds a whole new level of coolness to the whole spawning event. Think of it: a massive group mating that rivals even the worst excesses of ancient Rome or the 1970s, happening right here on the beaches, reminding us of the magnificent diversity and perversion of the animal world! (And I mean that in the very best way possible.)

And did we see it happen?

All will be revealed in the next installment of Arthropod Voyeurship!

{A note: I do write all text and take all pictures. Please do not reproduce either without my permission.}