Research study 1
Tubeworms rely on their tentacles both for feeding and gas exchange. However, studies on Eudistylia vancouveri at Friday Harbor Laboratories, Washington show that the general body epidermis is additionally involved in gas exchange, aided by up-and-down “irrigatory” movements of the body in its tube. The movements are cyclical peristalses occurring about 14 times per hour over durations of 30sec each. One such cycle is shown in the series of drawings on the Left, involving a contraction that moves down the worm's body. If the tentacles are removed, oxygen uptake decreases by about 80%, and the worm responds by greatly increasing the frequency of the irrigations.
NOTE most or all tubeworms have good powers of regeneration, especially of their vulnerable crown of feeding tentacles, so if these are experimentally removed the worms should recover quickly. The author allows periods of 24-48h for recovery before measuring rates of oxygen consumption in the crownless individuals. Having said this and in view of potential trauma associated with removal of the crown, perhaps the author should have included a mock-surgery control
NOTE except for this fact, the up-and-down movements in the tube described by the author might have been interpreted as normal cleaning behaviour (e.g., for feces and urine), and presumably these functions are being met by the movements in normal as well as crownless individuals
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