Opisthosome
Like the vestimentum, the opisthosome produces new tube material and helps
anchor the worm in its tube, which is often planted deep within the crevices of
a black smoker. Giant tubeworms can reach well over a yard long, and the
temperatures they have to cope with over that length boggle the mind. Imagine
having your head in near-freezing water and your foot planted in scalding rock.
That's what tubeworms have to deal with: biologists have measured temperatures
at a worm's plume of 35°F while that at its base is 86°F.
