Because the timing for each subgroup of clam worm might vary a smidge, it will be a long time before anybody nails down exactly when the swarm will occur from year to year.
Since clam worms are widely distributed around the world, it's not shocking that they are found in Florida.
Finding specific habitat requirements for the clam worms has been almost impossible (since nobody can usually identify exactly what the worm is), but other information about the lifecycle of clam worms suggest that quality habitat is critical.
In an upcoming issue of the Proceedings of the National Academy of Sciences, the researchers compare the bloodworm's jaws to those of the clam worm, Nereis limbata, a sand- and mud-dwelling scavenger.
The clam worm, which scavenges food, may not require jaws as hard as those of the bloodworm, which thrusts its jaws into prey to inject venom.