Biologist Cracks Some Deep Mysteries of Lobsters’ Lively Society
An hour or two every night, winter and summer for seven years, Jelle Atema floated face down in an eight-foot-deep tidal bay and watched the lobsters.
What he saw in this alien place just a few wet steps offshore amazed him.
His pea-brained lobsters, so fearsome, so primitive, have an awesomely complex ability to taste and smell and sense the sea around them.
Schmoozing, Scouting, Sex
They pass their nights schmoozing with neighbors, scouting out rivals and appraising the real estate. They mate with a poignant gentleness that is almost human. They are artful, snoopy and gregarious.
No one would have expected the lowly American lobster to own such a fertile culture. No one, until Atema, had taken the time to pry into its secret world.
Atema is a biologist who clearly loves his biota.
The drift of modern science is to specialize, to focus on some minutia of nature’s processes, to know more and more about less and less. Atema’s arcanum is the hair-like sense organs that orient lobsters to the world around them. Early in his career, it occurred to him that before he could learn how these structures guide lobsters’ behavior, he had to understand lobsters’ behavior.
So began his undersea reconnaissance. At first, Atema did it mostly on his own time. He was helped by students, lab technicians and friends, but it was as much a hobby as a job. His real work, the research that government agencies paid him for, was lab experiments on the effects of pollution on lobsters’ senses and actions.
“It was an incredible investment in time in today’s science,” he said. “And the only way I could do it was by putting it on the back burner and sort of spinning it off other projects.”
Jelle Atema (pronounced YELL-ah ATT-ah-ma) is a slender, fit-looking man who pads about his labs in T-shirt, shorts and flip-flops. All but the faintest trace of his native Dutch (sometimes his w’s still begin as v’s) has been banished from his voice.
At age 44, he is a full professor in the Boston University Marine Program at the Marine Biological Laboratory in Woods Hole, a semiautonomous chief in the subculture of academic research. From his cinder-block basement office, he oversees two postdoctoral students, a technician, a dozen or so graduate students and a complex of labs that includes large aquariums filled with lobsters, cunners, snails, mussels, rocks, seaweed and other staples of the ocean bottom.
His interest in lobsters--his obsession, really--began in 1970. He arrived in Woods Hole, a brainy village of research labs, with fractured English and some knowledge about the specialized organs called chemoreceptors.
Logic and serendipity led him to the lobster.
The three years before, as a postdoctoral student in Michigan, he had looked into the way catfish process chemical signals from the water. There are no catfish in Buzzards Bay. So, after looking around a bit, he decided to experiment with lobsters. They are a manageable size for experiments, they are plentiful in the cool Cape Cod waters and they have chemoreceptors, the sense organs that cover many fish and crustaceans.
Atema marvels, 15 years later, at the wisdom of his choice. “I could have never dreamed of the riches that have come out of it,” he said.
Atema began looking that first summer in Woods Hole for the chemical signals that lobsters send and receive in their mating rituals.
Female Sex Hormone
“Within a few months--it was incredibly fast--I discovered that there is a female sex pheromone in lobsters,” he said. “It is an outside hormone, a set of substances that the female produces when she courts the male to make herself attractive. It was tremendously exciting to work that fast. I was proud of myself that I’d picked the right animal and tickled it to give me an interesting piece of information.”
At that point, Atema could have moved on to some other marine creature, but he didn’t.
“I feel it’s very important to not just skim the goodies off the top and then hop on to the next thing,” he said. “I wanted to really figure it out. What is the chemical composition of this substance? And how is it used in the animal’s biology?”
This urge to really figure it out drives many scientists. They freely admit that they don’t have much interest in the practical uses of their work, if, indeed, there are any. Even articulate researchers such as Atema have trouble spelling out precisely what it is that keeps them going.
Basic Curiosity
“My interest in science is basic curiosity,” he said after thinking about it. “Why is the world the way it is? Why do we see it this way?
“It is very beautiful to study things in nature and see how it all fits together. To me, the attraction is not so much how it is applied. It’s simply exciting to keep on investigating, to see more details and to tell people about it, to show them beautiful aspects of our world.”
So that first summer, aglow with his lightning-start success, Atema set off toward his next reasonable goal--deciphering the chemistry of the lobster pheromone. It was a cardinal mistake.
Instead, he should have tried to learn how the chemical is used in lobster courtship and how it involves the creature’s biology. But it took two years of fizzled experiments to realize that he had been misled by moths.
Female moths also give off pheromones. Males spend their adulthoods tracking this smell. They don’t even eat. They are sexually guided fliers.
Lobsters, it turns out, are a totally different story, but no one knew that.
“We assumed, sort of without specifying it to ourselves, that lobsters were working the same way,” Atema said.
“We designed a test that required the female to be in one place and the male to run up-current and find the source of the pheromone. We did some initial tests that seemed to work that way. It strengthened our bias. After two years of failure, I decided it was obviously not the way to go. We really must look at the lobster as a whole animal in its environment and understand the context of the pheromone. That’s when we started our work in the field.”
Nocturnal Animals
Lobsters are mostly nocturnal, so, each evening, Atema and his colleagues boated off to a shallow stretch of shoreline on Naushon Island. There they put on wet suits and floated quietly, night after night, searching the bottom with dim flashlights. Each lobster was given a number. The researchers carried underwater note pads and wrote down everything they saw.
“It was the turning point,” Atema said. “After those seven years, we published a paper describing the courtship and the use of pheromones. That has been the foundation upon which we still work.”
Instead of sitting in one place and waiting for a male to seek out her scent, as a moth would, the female lobster approaches a male’s burrow a few days before she’s ready to shed her shell. Then, she squirts in her pheromone.
The male lets her in, the female molts, and the pair gently mate, the male cautiously avoiding harm to the soft-shelled, vulnerable female. Then the two live together for a few days while the female’s new shell hardens.
Lobsters Don’t Roam
Atema’s observations destroyed other myths about lobsters’ behavior. For instance, the animals were widely thought to be vagabonds. Atema found that they often live a year or longer in the same crevice in the rocks, and they can find their home if moved hundreds of feet away.
The lobsters also have a social order. In any area, there is a dominant male with whom females prefer to mate. In fact, female lobsters somehow stagger their molting so that each has a chance at the preferred mate.
“For me, the most curious impression is that the animals are active at night without seeming to be engaged in feeding or anything obvious,” Atema said. “My interpretation is that they’re scouting about to learn both the social and physical environment.”
The lobsters seem to be checking out shelters that are available in case of danger, noting the arrival of new lobsters and keeping track of eligible mates.
Top Dogs
Each discovery reveals fresh mysteries: How do dominant males become the top dogs? How do females stagger their molt cycles? And always the two basic questions: What is the purpose of this behavior? What is the physiology that makes it possible?
Atema’s knowledge of lobster doings has also provided clues in his drive to understand the animals’ sense organs, the chemoreceptors.
Again, a puzzle: How, in an ocean full of chemical smells, does a lobster sniff out his lunch? The key this time was amino acids, the construction material of proteins.
“The animals that lobsters like to eat exude amino acids,” said Atema. “If the lobster wants to feed, it has to discriminate a particular mixture above the existing background. It’s similar to hearing a meaningful sound in a noisy room.”
Amino Acids Detected
The lobster’s antennae, mouth, legs and entire shell are covered with chemoreceptors. Atema discovered that each chemoreceptor is finely tuned to detect just a single amino acid. When the lobster’s body picks up a particular blend of amino acids, such as the chemical signature of a mussel, its brain interprets this to mean food, and the animal walks off in the direction of the scent.
Knowing these things may turn out to have practical uses for protecting the species in the seas and coaxing them to live and breed in aquatic farms to feed the world. To Atema, these are interesting byproducts. They are not, however, what entices him back to his lab each day.
“If there were no contribution to society, would I still do it? If I could afford it, I would,” he said. “But it’s irrelevant, because I am convinced--and maybe I’ve just convinced myself from some psychological need to do so--that I am making a contribution to society. I think I’m giving people a different perspective on nature.”
Curiosity Has Limits
However, his curiosity, his desire to know and to inform, has limits.
“I don’t like to cut up lobsters,” he said. “I think they are very beautiful animals. I cut off a leg or an antenna to study single cells, but these grow back, so it doesn’t hurt me so much. I would be very hard pressed to, day after day, decapitate a lobster and work on its brain.”
Once or twice a year he dines on lobster, but only when he goes to Maine. That way, he said, “I’m sure I’m not eating my friends.”
