SIZE, DISTRIBUTION, AND SIGNIFICANCE OF CAPITULAR PLATES IN OCTOLASMIS (CIRRIPEDIA, POECILASMATIDAE)

All adult Octolasmis live permanently fixed to animate hosts by a basa l attachment disc. The peduncle connects the disc to the plated capitu lum. The area of the capitular plates and the capitular perimeter bord ered by plates is assessed for 28 species of Octolasmis. A hypothesis that the species of Octolasmis that live inside decapod gill chambers will have smaller, more variable plates than those species that live o n the exposed external surface of their hosts is articulated and teste d. The data support the hypothesis under general conditions and also r eveal an array of special circumstances suggesting that several aspect s of host morphology and habits may also impact on the intensity of se lection on capitular plate size and distribution.