Functional morphology of lumbricid earthworms, with special reference to locomotion

Abstract

Summary Observations on the vertical distribution of earthworms in pasture confirm that Allolobophora longa, A. rosea and Lumbricus terrestris are relatively deep burrowers, and that the adults of these species burrow deeper than juveniles. Deep burrowing species have more elongated bodies than surface dwellers such as Dendrobaena mammalis and L. castaneus, and adults have more elongated bodies than juveniles. Long-bodied species tend to have more segments than short-bodied ones. On the limited evidence available, increase in relative thinness with age is not, apparently, associated with increased number of segments in A. rosea or L. terrestris but is in A. caliginosa and A. longa, and to a lesser extent in A. chlorotica. In adults and juveniles the diameter of the anterior region is greater than that of the posterior region of the body, and the latter is more strongly flattened dorsoventrally than the former. Such morphological differentiation is consistent with the differences in function of the anterio...