Adaptations of crustose coralline algae to herbivory: patterns in space and time.

Abstract

Examines the coexistence and coadaptation of crustose coralline algae with grazing herbivores. Observes that crustose coralline algae are among the most abundant organisms, whether plant or animal, occupying the hard substrate in the photic zone. In face, since coralline algae are more diverse and abundant today than in any other geological period, the author calls the Holocene an Age of Crustose Corallines. The Holocene also appears to be a time of maximum intensity of marine herbivory. Steneck correlates temporally the radiation of crustose corallines with coralline-grazing herbivores. Ecological and paleontological research suggests that there are several anatomical and morphological adaptations to algal herbivory, identified by finding convergently evolved characters of similar function under different physical conditions. These specific adaptations are crust thickness, branching morphology, conceptacle shape, and protection of the growth region. Today, geographic patterns of these characters correspond with geographic patterns in the distribution and abundance of herbivore groups. Coralline taxa with these adaptations appear to have progressively increased throughout the Phanerozoic, corresponding to the increased pressure of herbivory. -from Editors