Feeding in Parrotfishes: The Influence of Species, Body Size, and Temperature

Abstract

Feeding, the process by which animals acquire nutrients, and hence energy for maintenance, growth and reproduction, is central to the health of individuals and populations. Indeed, variation in nutritional quality and quantity of diets are one of the most important determinants of animal fitness (Sterner and Elser 2002), and has led to several theories that relate the availability and/or quality of dietary resources to the foraging decisions of animals (e.g., Optimal Foraging Theory; Smith 1978). Although there has been debate as to the nutritional targets of parrotfishes, recent evidence suggests they are targeting protein-rich epilithic, endolithic and epiphytic microscopic phototrophs (Clements et al. 2017, Clements and Choat Chapter 3). The primary goal of feeding in parrotfishes must be to acquire sufficient nutrients from these dietary sources to fuel metabolic processes, and hence the spatial and temporal variation in the quality and quantity of these resources may shape the distribution and foraging patterns of parrotfishes (e.g., Russ et al. 2015). Despite sharing broadly similar diets, there is considerable inter- and intra-specific variation in the way parrotfishes feed, in particular the frequency of feeding and the extent to which they disturb benthic communities when feeding (e.g., Bellwood and Choat 1990, Bruggemann et al. 1994a, b).