DIRECTLY MEASURED RAPID GROWTH OF A DEEP-SEA BARNACLE

ESTIMATES of the growth rates of organisms in the deep sea have usually been indirect owing to the remote and hostile nature of this environment. Consequently, it is not clear whether slow growth rates are the general rule1 or the exception2-4. I have now directly measured the growth rate of a barnacle on the deep-sea floor. To my knowledge this is the first direct measurement of the growth of a deep-sea specimen in its natural habitat: previous direct measurements have been unrepresentative, coming from hydrothermal vents. Measurements of the length of the barnacle over a period of seven months demonstrate a high growth rate: the body length increased from less than ∼1 mm to 10 mm in only six months, and the specimen probably reached sexual maturity in about seven months. This rate seems to be greatly enhanced by the annual deposition of phytodetrital material. © 1990 Nature Publishing Group.