Thursday, July 27, 2017

Limbs with Limpets: a Resolved Mystery

Check out that mystery hitchhiker on the left claw!
At the Children's Museum, we are pulling up a near constant stream of crabs from our crab traps; there have been days where we catch close to 80 crabs over the course of the day! All the crabs we catch are put into our touch tanks where we can show them to kids and get a close up look at what they look like. It's fun to peer into their beady little eyes, explore what they're hiding underneath their aprons, and see how many legs they're missing. It's also not uncommon for these crabs to have an entire collection of barnacles on their backs!

A few weeks ago, we found a crab with a mysterious hard growth on its claw. Unlike a barnacle, this growth was oval-shaped, smooth, and a dark grey color. We tried to pry off whatever this was so we could get a closer look at it, but it refused to budge! Resigned, we left the crab alone, but we knew we had to figure out what this strange lump was. 

The next morning we pulled up another crab with the mysterious growth. After careful inspection and flipping through our guidebook, we still couldn't identify what it was, so we put the crab back in the tank and pushed it to the back of our minds. After an hour or so, we picked up the crab again and noticed that the mysterious growth had moved! So from there we determined that it was less of a growth and more of a hitchhiker. 

Time passed and we didn't see any more crabs with hitchhikers until yesterday. This particular critter wasn't quite as strong his other brethren we had caught before, and popped off the crab with a gentle nudge. Eagerly, we flipped it over to investigate what had been puzzling us for weeks. 

We found that, as we suspected, the critter had a snail-like foot underneath that smooth grey shell! So we pulled out our guidebook and looked carefully at all the snails, but they all seemed to have long, conical shells instead of smooth, flat ones. So snails were out. 

I reached out to some of the other Senior Harbor Explorers to see if they had any ideas. Jenn mentioned that it might be a limpet, so we reached for our trusty guidebook once more and searched for the limpets. As soon as we saw the first picture we knew that Jenn was definitely right - these hitchhikers were absolutely limpets!

We're so excited this weeks-long mystery was finally resolved. Another day, another critter. Thanks Jenn for your help!

Until our next breaking discovery,

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