Crustacean identification

I’ve lived on the Cape a year and a half now, and the question I’ve asked more than any other (with the possible exception of “What am I doing here?”) is “What is this?”

There are variations on this question, like “What on earth is this?” and “What the hell is this?” My husband has his own, unprintable version. However we phrase it, the problem is the same: identification.

Back in Manhattan, there were plenty of things I couldn’t identify, but identification was less important. I could kill the crawly thing in my bathtub without knowing what it was. I could admire the flowering tree without putting a name to it. Identification is a higher priority, though, for things you’re planning to eat.

Sometimes, like with mushrooms, it’s absolutely critical. Other times, it’s just very useful. I’m willing to sample just about any green plant I come across, but knowing which ones taste good would save me some significant nastiness. Still other times it’s merely window dressing. You’d think a rainbow trout and a brown trout would be pretty easy to tell apart, what with their distinguishing characteristic right there in their name, but I’m here to tell you it’s just easy enough that everyone expects you to get it right, but just hard enough that you sometimes don’t.

Crabs are way harder than trout. I came home from my last trip to a heap of them, the bycatch from Kevin’s last lobstering expedition, and I didn’t have the first clue what kind they were. They certainly looked edible, so I sampled a claw. Tasted fine. Good, even – briny and sweet. But I wanted a positive ID.

Before the Internet age, it would have been hopeless. Post-Internet, it’s merely difficult. All crabs look similar, but there are distinct differences. Those differences make it easy to tell pictures of crabs apart, but it’s still hard to identify actual specimens. Sure, one kind has nine “teeth” and one kind has only seven, but does that little thing next to the eye count as a tooth? How about that last little indentation by the claw?

People who know about the creatures in our local seas tell me they’re rock crabs, but I’m not so sure. For starters, there are a zillion kinds of rock crabs – red rock, brown rock, Pacific rock, pygmy rock – and they’re almost impossible to tell apart. Some people say the rock crab and the peekytoe are the same species; others insist that they’re different. I never found a picture of a rock crab that looked exactly like the crabs we caught.

My money’s on the Jonah crab, which is reportedly a relative of the Dungeness. Not that I found a picture of one of those that was an exact match, but I think it was closer.

What I really need is a carcinologist – that’s the formal name for someone who studies crustaceans. For obvious reasons, they don’t use the frowned-upon but still correct “crustalogist,” which sounds like someone with a baking sub-specialty, or maybe someone who can tell me about those little hard scabs our cat gets in the fall.

But the crabmeat was delicious, and a Jonah crab by any other name …

9 people are having a conversation about “Crustacean identification

  1. It feels odd to be arguing about crustacean identification from 3,000 miles away instead of being in our respective livingroom chairs with a glass of wine.
    That being said I think your pictures clearly show the Jonah has narrower and smaller claws than the “rock” crabs I pulled from the depths of Cape Cod Bay.
    I’m sticking with my original ID.

  2. I’m glad you said that the Jonah was related to the Dungeness, because I took one look at it and thought, “Wow- what’s a Dungeness crab doing all the way over on the east coast?”

    I think I will use ‘crustologist’ to describe my husband, because although he can bake a loaf of bread with an awesome crust and toothsome crumb, he is very crabby, a lot of the time….especially when he’s waiting for a meal, which reminds me I’d better go look at the soup.

  3. …then there’s the school that thinks that identifying it as a crab and not a doorstop or an ashtray is good enough….

  4. I LOVE learning new words, especially sciency ones. Now, how to get carcinologist into a sentence…

    Are there any species of crab that are poisonous?

  5. LOVE this. Am endlessly fascinated by crabs. My son Max spends 100 hours in the summer looking for them on our beach with his pal Kenzie. Kenzie knows more about the ocean and all things that live in it than anyone I know…yes, she’s 8.

  6. The only data I’m going on is that I’ve lived here 35 years and have seen the top crab sold only as rock crab. I always find them at Joe’s Lobster Mart in Sandwich. Delicious.

    However none so delicious as the kind of crabs we have caught on the Cape: blue crabs. The bottom of one claw is blue – and the shape is different from the others pictured. We catch them from shore. They’re the same as the crabs in Maryland. They’ll be available for only a couple of more weeks. They’re at their largest of the season – now. There are requirements; no females can be taken and the crab has to measure a certain size from one end to the other of the carapiece?? (that may be the turtle’s shell; not the crab).

    They’re in south side estuaries. Everywhere on the Cape.

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