Atema and his students made their discovery on the lobsters' use of smelling sensors by analyzing a series of boxing matches they staged in an aquarium tank.
The researchers placed eight lobsters of equal size that had never met before in the tank and watched as they engaged in often bruising battles to establish dominance. An hour later, however, the lobsters were relatively calm and settling into their digs.
"It makes sense," Atema said. "They live ultimately in a small community where they are relatively local and meet the neighbors on a regular basis. Why waste time fighting with the neighbors?"
When the same lobsters were reintroduced after a days' separation, they only interacted long enough to catch a whiff of each other and recall who was the more dominant. "The loser says, Oh no, I know that guy, and goes away," Atema said.
But if the loser is introduced to a new lobster, he'll engage in a fresh battle. As well, familiar lobsters fought anew when their smelling sensors on the end of their small antennae were shaved off.
This indicates that lobsters need the structures to recognize each other, Atema and Johnson concluded in their paper.
Atema aims to ultimately explain how creatures such as lobsters use chemical signals to understand their underwater environment. "It's not something many people study," he said.
In addition to smelling sensors on their small antennae, lobsters have tiny hairs on their feet and the appendages around their mouths that give the crustaceans a sense of taste.
In other words, Atema says, they can grab a piece of food with the little claws on their feet, taste it, then bring it up to their mouth and taste it again.
The system of two sets of taste, which Atema says is fairly common in the underwater world, acts as a safeguard against eating spoiled food.
Cowan, of the Lobster Conservancy, says that as biologists discover how much lobsters rely on chemical sensors to interact with their environment, fishery managers are gaining a better understanding of how to maintain a healthy lobster industry.
For example, she says, many lobsters reside in the near-shore environment and thus are susceptible to human impacts along the shoreline, such as pollution.
"Many pollutants can mess up [lobsters'] sense of smell, which would be very detrimental, because they are using it to communicate and find each other and reproduce," she said.
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