Life Cycle Of A Crab

Some animals attract mates by collecting shiny objects. Others puff up their plumage and perform intricate dance recitals. Some squirt their seed into the atmosphere, others need to get up close and personal to make the whole thing work and more than a few of us do it simply because it’s a whole lot of fun.

The act of reproduction — whether we get tender, homicidal or downright freaky — is a ritual that unites all living citizens of Earth.

Take the Dungeness crab, bottom feeder of the cold coastal waters between Alaska and California. Named after a town on the wide Strait of Juan de Fuca, their path to grandchildren is blocked by an unhelpful reliance on a rock-hard exoskeleton. As they grow, Dungeness crabs must shed this exoskeleton in an apparently difficult and time-consuming process called “molting.” This involves detaching and then pushing themselves backwards out of the old shell — legs, pinchers, face and all. It is only at this moment, when the crab’s new shell is still soft and supple, that females are able to mate.

As the female molting months of May and June approach, male crabs boost their reproductive chances by finding a female, flipping her onto her back and pinning the poor woman down in a so-called “protective embrace.” Having achieved this abdomen-to-abdomen position, the pair settle in to wait — which can take anywhere from a few days to two whole weeks. When she is at last ready, the female lets her partner know by urinating on his face antennae. Now, maybe Dungies are freaky and into that sort of thing, but I suspect this method of signalling is a small revenge for two weeks of uncomfortable coupling and boorish stories about brawls with local red rock crabs.

In any case, the act is a signal that she’s almost ready. Once she has molted out of the old shell, the male deposits his seed in her elegantly named “sperm receptacle.” She will carry it with her until autumn, at which point she’ll start dropping eggs in the sperm bin and hatching millimetre-long larvae. Over the next two years, these larvae lose their tail as they swim the cold west coast currents, dodging hungry grey whales, salmon and others. They molt up to six times each year until reaching maturity at the age of three.

Each year, from July through September, metal boxes and cages begin descending out of the watery light above to settle on the fetid floor of Puget Sound. These containers hold payloads of old meat — fish, shrimp, turkey — often rubbed with some combination of oil and pheromones designed to drive the Dungeness mad. Roving crabs congregate, wandering through one-way flaps while their smarter companions presumably roll their eyes at larvae broods and mutter, “Kids, say goodbye to Uncle Daryl.”

Photo via YouTube

After an hour or two, the box ascends into the light as mysteriously as it arrived. The trap — for it is a trap — soon breaches the surface and Uncle Daryl and his mates find themselves on the floor of a small boat. Towering homo sapiens — for example, Hailee and I on a recent afternoon near Friday Harbor, in the San Juan Islands — then gingerly fish each crab out of the pot, careful to avoid the panicked swivelling of Dungeness claws.

According to local laws, any male crab with a shell wider than a dollar bill is long is eligible for eating. So the females — identified by a rounded marking on their abdomens — and smaller males are tossed back into the briny drink to tell wild stories of above. Meanwhile, Daryl and his unlucky mates go into a bucket of seawater as Hailee and I motor back to a nearby dock.

From here, the crabs enjoy a brief moment of celebrity as other humans peek into the bucket and congratulate the crab trappers on their catch. But at this point, I suspect the crabs know their fate. 

Sorry Uncle Daryl, you were delicious.

An appointed human soon takes the bucket down to a quiet, rocky spot by the water for the private business of “cleaning” the crab. One-by-one, the cleaner grips them, positions their rear against the sharp edge of a rock and, in a quick moment (I still haven’t mastered this technique), cracks down in a way that dislodges the shell from the rest of the crab, killing it almost instantly. This is an intimate moment — crab and human look one another in the eye as it happens — and I imagine the crabs do feel some pain. But it is all over mercifully quick, and the fisheries are regulated in such a way that catching and eating the Dungeness doesn’t prevent their community from performing its essential duties within the wider ecosystem.

The shell-less body is then cracked in half and the guts are washed away, leaving clean, white meat gleaming from the legs and a series of cavernous deposits within its chest. The assorted sets of legs and pinchers are then boiled — during which Dungeness shells turn from brown to bright red — and served in great piles, along with implements for cracking open the hard shells and cleaning out the tender, sweet meat within. There are a number of popular condiments, though melted butter and cocktail sauce with horseradish are popular among the crew I usually run with in the islands.

This whole process generally ends with humans leaning back and rubbing bellies, assuring one another that they couldn’t possibly eat another bite. They gather the leftover meat for midweek crab cakes, and fling the cracked and stripped shells back into the water from whence they came. And as the humans wander inside, the still twilight water might bend and ripple, betraying the presence of a seal making its own dinner on the fish who congregate to pick over the remains.

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