for National Geographic News
Jelle Atema says when he first encountered lobsters as a young marine biologist in the 1970s, he was surprised at how peaceful the giant-clawed crustaceans behaved toward each other.
"I'd swim around and see lobsters meet each other, give a display, raise their claws. But there was not much fighting," the professor at Boston University's Marine Program in Woods Hole, Massachusetts, said.
Now he understands that those lobsters already knew each other. A few swishes of their small antennae were all they needed to pick up the other's scent and recall their earlier battle that established who was dominant.
Yes, lobsters' small antennae work like the human nose, only the crustaceans' sense of smell is keener. They recognize individuals purely by their odor, Atema says.
The antennae are packed with chemical sensors called aesthetascs. Odor molecules diffuse onto these sensors, which route a signal to a region of the brain where smells are processed and identified.
Atema and colleague Meg Johnson reported the finding on individual odor recognition in the July issue of the Journal of Experimental Biology.
"Being able to show lobsters can identify each other individually by odor is quite a feat because lobsters don't communicate the way we do," said Diane Cowan, president of the Lobster Conservancy in Friendship, Maine.
Cowan, who has collaborated with Atema on research in the past, adds that any finding on how lobsters navigate their environment is helpful to her organization's goal of sustaining a thriving lobster fishery.
"Without lobsters successfully finding each other to mate and reproduce there is no future for the lobster industry," she said.
Recognizing individuals is important for lobsters because it allows the crustaceans to know where they fit in the pecking order, Atema says. The hierarchy establishes which lobster is the most dominant and thus can claim the most protected shelter in the neighborhood.
And when a female lobster comes sniffing around for a mate, she's on the prowl for the most dominant male.
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