Since the discovery of tubeworms in 1977, scientists have been scratching their heads about vent colonization. After all, these tubeworms have specifically adapted to a highly specialized environment that has the capricious quality of switching on and off at random. And, to add another layer of difficulty to tubeworm propagation, the vents are little oases on the vast desert of the seafloor. How do organisms that are rooted to the ground spread to another vent that might be more than 50 miles (80 kilometers) away?
After much intensive and inventive research, scientists are closing in on an answer. To start with, it's important to know how tubeworms make babies. That part is easy: They do it the same way shellfish do, by unleashing eggs and sperm into the water. The sperm bump into the eggs and combine to form larvae. The larvae drift on the currents like dandelion spores on the wind, until they come to rest, hopefully on a hospitable spot suited to their highly specific needs — i.e., a vent.
Here's where things get interesting: It turns out that those larvae are born with a ton of energy. Not rambunctious-toddler energy, but stored energy in the form of lipids. In fact, they've got enough of the stuff to last for 40 days.
But still, within that 40-day allotment, how do those larvae get from point A to point B? Researchers had to be creative because trying to keep track of thousands of microscopic specks in the pitch darkness of the deep sea is no joke. They started by building computer models of the currents and then releasing virtual larvae into those currents. Once they had some interesting results, they dumped a harmless, trackable chemical compound near a vent and watched what happened.
They soon discovered that the currents around a vent can carry the little tubeworms-to-be along the mid-ocean ridges where vents are found. Even if the currents eddy and veer off course, they can still swing back and drop their passengers in hospitable vent territory where they can happily grow to full tubeworm adulthood [source: Villano].