Not “The Blue Lagoon” with Brooke Shield for sure. Still, in mid-winter it’s sex on the beach but with little purple shore crabs. This time of year, your beach walk might include watching for these little crabs. They can reach high densities if you look in the right places – large boulders, lots of cobbles and piles of drift wrack. Variable in color from purple to reddish-brown, olive or even yellow, they all have reddish-purple spots on the claws and a lack of hair on their legs – the nude part of this story, but also their scientific name Hemigrapsus nudus. Adults are about an inch across a square-shaped carapace. After you spot one, carefully squat down for a look and watch the little eyes checking you out.
In late winter, shore crabs mate – the sex part of this story. Don’t think about how this works as it involves swimming legs, modified parts and typical male domination stuff. And just like Dungeness crabs, female shore crabs have wider abdomens than males, allowing them to carry masses of eggs around until they hatch, sometimes as many as 30,000 at one time. Eggs hang on as the female goes about life and then hatch in April or May. If you’re on the beach in early summer, look for tiny dime-sized baby shore crab skeletons that didn’t make it. These creatures are just a small part of what makes our beaches truly fun to explore. For me, it’s the small stuff of nature that is most interesting.
Larry Eifert paints and blogs about wild places at larryeifert.com. His work can be seen in many national parks across America.