A response of gorgonia (Pseudoplexaura spp.) To tissue invasion by the algae, Entocladia endozoica, in Florida and Caribbean waters. The host gorgonia react to the algal filaments by producing capsules (galls) composed of skeletal elements that isolate the algae from the host tissue, at the expense of the skeletons' tensile strength and elasticity. The gorgonium readily breaks apart at the sites of the weakened skeleton. For more information and illustrations, see: http://www.coral.noaa.gov/coral_disease/algal_galls.shtml.