From the deck of the Nautical Mile
Every autumn beneath Florida’s coastal waters, a remarkable phenomenon unfolds as the Florida spiny lobster (Panulirus argus) initiates an epic migration—a behavior that has fascinated scientists and divers alike.
As water temperatures drop with the changing season, thousands of these nocturnal crustaceans abandon their shallow summer refuges and embark on a journey to deeper, warmer offshore habitats where survival is more assured through the colder months.
What makes this migration especially intriguing is the way spiny lobsters organize themselves into long, single-file “marches” that crawl methodically across the sandy seafloor.
Often numbering dozens or even hundreds, these lines stretch up to several meters as the lobsters move in synchrony.
Rather than scatter as individuals, each lobster maintains close physical contact with the one ahead by gently placing its antennae on the legs of its predecessor—a behavior known as antenna-to-leg contact.
This coordinated movement is more than just a show of social behavior; it’s a clever survival tactic. By reducing drag resistance, the lobsters expend less energy navigating against ocean currents and avoid drawing the attention of predators by acting as a unified group.
The lead lobster, typically the largest or most experienced, guides the formation while subsequent lobsters rely on tactile signals to keep pace.
Researchers have found that such formations can significantly decrease the effort required to travel long distances and may also improve the group's detection of threats.
The Florida spiny lobster’s fall migration is one of the state’s most spectacular marine events, drawing divers to witness the so-called “lobster march” firsthand.
This seasonal trek not only highlights the species’ adaptability, but also serves as a vivid reminder of the interconnectedness found in nature’s underwater highways—a strategy refined over millions of years in the subtropical waters of the Atlantic and Gulf of Mexico.
10 Things You Didn’t Know:
Florida spiny lobsters are unique in many ways; here are ten facts about them that are often unknown to the general public:
1- No Claws: Unlike Maine lobsters, Florida spiny lobsters lack large front claws; they use their long, spiny antennae for defense instead.
2- Antennae as Weapons and Warning: Their two large antennae can be more than twice the body length and are used not just for defense, but to make screeching noises underwater to scare away predators by rubbing them on their shells.
3- Color-Changing Spots: They have two large, cream-colored spots on the second tail segment which help with identification, and their coloration can range from nearly white to deep red-orange.
4- Migration in Formation: Each fall, they form long, single-file “marches” across the sea floor to deeper waters when temperatures drop, following antenna-to-leg contact to reduce drag resistance.
5- Highly Social When Young: While solitary as larvae, juveniles often congregate together in clusters in protected shelters, using chemical cues in their urine to find healthy groups and avoid diseased individuals.
6- Egg-Carrying Females Must Be Released: In Florida, it is illegal to keep females carrying eggs (“in berry”)—these have orange eggs visible under their tails.
7- Live Mostly at Night: They are nocturnal, hiding in dens during the day and only emerging after dark to forage for food such as snails, clams, crabs, and urchins.
8- Tiny Planktonic Babies Travel Far: After larvae hatch, ocean currents can carry them for thousands of miles before they settle in shallow Florida seagrass beds to grow.
9- Protection from Overfishing: Strict regulations exist: there’s a two-day “mini-season” in late July before the main lobster season (August-March), and lobsters must meet a minimum size to be harvested.
10- Important for Florida’s Economy: The spiny lobster fishery is the second-largest in Florida by dollar value, bringing in over $40 million annually and supporting commercial as well as recreational fishing.
Additional interesting facts include that adults can live 15 years or potentially even longer, a single specimen can weigh up to 15 pounds (though most are much smaller), and these lobsters are sometimes called “rock lobster,” “crawfish,” or “langouste” in different regions.
Nautical Mile Magazine
