Abstract: Parrotfishes, a dominant group of grazing fishes have colonized tropical reef systems in all of the world’s ocean basins. As with other clades of the family Labridae they are largely protogynous with a characteristically complex reproductive ontogeny. In life-history terms they are dynamic, displaying a demographic signature characterised by rapid and highly opportunistic episodes of somatic growth and exceptionally high reproductive outputs. As relatively short-lived but abundant reef fishes their populations contain a high proportion of small, newly recruited individuals that occupy shallow high temperature habitats. This plus their demographic features implies a demanding metabolism and the requirement of substantial resources to support their abundant populations. In this context dietary selectivity and food processing becomes a matter of considerable interest. This seminar examines the alternatives with respect to food resources with a focus on the capacity of algal resources to support parrotfish populations. Examination of this issue also provides clues as to the rapid evolutionary diversification of this group associated with the colonization of the world’s tropical reefs over a relatively short time period.

Bio: JH Choat late of University of Queensland, University of Auckland, James Cook University Department of Marine Biology. Is now retired and from an adjunct appointment is continuing studies of the demography and nutritional ecology of parrot fishes at several sites including the east Pacific, southern Brazil, the Red Sea and Oman, Cocos-Keeling the Solomon Islands, Micronesia and the GBR.