The complicated mating rituals of Maine lobsters might make you turn red.
By Virginia M. Wright
Excerpted from The Maine Lobster Book, by Virginia M. Wright, Down East Books, Camden, Maine; hardcover; 114 pages; $14.95.
Image ©IStockPhoto.com/JoeiVanVeen
A lady lobster knows what she wants, and what she wants is the guy with a reputation for toughness and strength, the guy all the other lobsters in the neighborhood fear and respect. So she woos him. She leaves gifts — urchins, mussels, sea stars — at his front door. When she has his attention, she boldly moves in. And once they are better acquainted — a few days perhaps — she shimmies out of her tight suit of armor, exposing herself in all her soft, naked vulnerability. Summoning her strength (molting is an exhausting affair that leaves her limp as a strand of seaweed for nearly an hour), she raises her antennae to fondle her mate’s rostrum, the hornlike projection between his eyes. He reciprocates, his own antennae roaming eagerly over her body. Using his legs, he gently rolls her onto her back and deposits capsules of his sperm into a pocket on her abdomen.
“She’s just using him in a way,” Diane Cowan, a lobster biologist and founder of the Lobster Conservancy, says wryly of this crustacean courtship. “What she really needs is a safe place to molt. In science talk, they call it resource defense polygyny, where a male is defending a resource that the female needs.”
Indeed, once the female’s new shell is sufficiently hardened, she moves out, having no further use for her mate. Chances are good his sperm will go to waste because, if she is young, the female could well molt again before she releases her eggs, shedding the sperm in the process. Or, she may inflict the ultimate snub, jettisoning her ex’s sperm packet into the briny blue should she meet a suitor she fancies more. (Pity not the male lobster. Stud muffin that he is, he likely took on a new housemate soon after his erstwhile partner’s departure.)
All of which is surprisingly complicated behavior for the creatures we in Maine have nicknamed “bugs,” not only for their creepy-crawly appearance, but also for their brains — or rather, their lack thereof. Lobsters have primitive nervous systems similar to those of insects, which suggests they are no smarter than a grasshopper. Yet these ancient members of the arthropod class of animals (invertebrates with segmented bodies and exoskeletons of chitin) continue to reveal previously unknown facets of their lives to scientists like Cowan, who has devoted all of her adult life to studying lobsters. They also are capable of acts of cunning.
Consider, for example, University of New Hampshire zoologist Win Watson’s stunning 2003 underwater video that shows lobsters of all shapes and sizes treating a baited trap like a drive-through restaurant. Ninety-three percent of the lobsters that enter the trap gorge themselves on the salted herring, then find their way out, prompting Pat White of the Maine Lobstermen’s Association to tell the Christian Science Monitor, “It’s pretty discouraging to think that we, as intelligent human beings, have been trying our best to harvest this thing that has no brain to speak of and they’re outsmarting us. But it may be that part of the success of our fishery is due to the fact that our traps are as inefficient as they are.” (Watch Professor Watson’s videos)
Commercially fished for 150 years, the American lobster, or Homarus americanus, dwells in the North Atlantic from North Carolina to Labrador and is most plentiful in the Gulf of Maine. Lobsters lead an itinerant lifestyle, determined by the seasons. Late spring and summer finds them dwelling in warmer waters inshore (“warm water” in Maine is fifty-two to sixty-two degrees). Come fall, they migrate to the deeper waters fifteen to forty miles offshore, which is why most Maine lobstermen don’t fish in winter — getting to where the lobsters are is time-consuming, bitterly cold, and potentially dangerous.
Let’s skip the debate over which came first, the lobster or the egg, and return to our lady lobster, who, for the convenience of this narrative, is still carrying her lover boy’s sperm when she spawns, an event that occurs about once every two years. As she squirts out her eggs — ten thousand to one hundred thousand of them, depending on her age and size — she also fertilizes them by simultaneously releasing the sperm packets. Attaching the eggs to the underside of her tail with a sticky substance produced by her swimmerets, she carries them for nine to twelve months while they develop. Should a Maine lobsterman catch her during this period, he cannot keep her. Instead, he must cut a small V-notch into her tail fin and throw her back into the sea, and as long as she bears that V-shaped scar, she cannot be sold, even if she is caught not bearing eggs. As a fertile female, she is worth more to the fishery alive and making babies than fetching a few bucks as someone’s dinner.
When the eggs hatch, the lobster releases them by fanning her swimmerets. The tiny flea-like larvae spend the next four to six weeks floating on the sea currents, shedding four times in the process. This is the most dangerous time of their lives, Cowan says, because “everything with a mouth big enough eats them.” Only one-tenth of 1 percent of them survive to the fourth stage, when they look like miniature lobsters, each one smaller than your thumbnail. The small fry swim toward shore and dive to the ocean floor to find shelter under rocks and weeds.
In these lobster nurseries, which Cowan’s Lobster Conservancy studies and seeks to protect, the lobsters live and grow. As they get bigger and bolder, they expand their range and move into deeper waters. It will be at least seven years before any of them reach the minimum legal size for market — 3¼ inches from the eyes to the beginning of the tail, about 1 pound. About that same time, the females reach sexual maturity. They get what Cowan calls PMS — pre-molt syndrome — when, like their mother before them, they tidy up their shelters and walk the watery streets in search of the toughest guy in the neighborhood.