From Biology News Network:
Giant deep-sea tubeworm’s meal ticket comes in as a skin infection
Giant tubeworms found near hydrothermal vents more than a mile below the ocean surface do not bother to eat: lacking mouth and stomach, they stand rooted to one spot.
For nourishment, they rely completely on symbiotic bacteria that live within their bodies to metabolize the sulphurous volcanic soup in which they both thrive.
But the microscopic larvae of these giants are born bacteria-free, with a complete digestive system.
Juveniles swim, hunt, and eat before permanently settling down and taking up with their microbial partners.
Now the idea that the larvae acquire their symbionts by eating them has been overturned.
By collecting the giant worms’ tiny spawn from traps laid on the oceanfloor, oceanographers have shown that the sulfur-eating bacteria infect the larvae through their skin.
Andrea Nussbaumer and Monika Bright of the University of Vienna, and Charles Fisher, professor of biology at Penn State, report their findings this week in the British journal Nature.
These tubeworms are Vestimentifera, known more recently as Siboglinidae.
See also here.
These record-breaking tube worms can survive for centuries. One deep-sea species can live more than 300 years, the longest of its kind. By Maria Temming, 11:00am, August 8, 2017.
Not really close relatives of earthworms, written about by Charles Darwin.