Meeting Abstract
Local adaptation is a phenomenon observed across a variety of species in which populations develop behavioral, morphological, and physiological traits which help them survive in their environment. Trinidadian guppies, Poecilia reticulata, are a model for studies of local adaptation. Upstream low predation (LP) populations experience higher population density and lower resource availability compared to downstream high predation (HP) populations. Differences in prey selection, feeding rate, and cranial morphology between populations indicate that feeding kinematics may be a locally adapted trait, however, recent work does not support this hypothesis at a population level. We hypothesize that within dense low predation populations, individuals may be driven to specialize to avoid resource competition, leading to differences in feeding kinematics that are not observable between populations. Using wild caught female guppies from replicate rivers, feeding kinematics were measured for three videos per fish then analyzed to determine how individuals vary when compared to their respective populations. Individuals in at least one HP population tend to specialize, contradicting expectations that intraspecific competition may drive specialization. Because this effect is not correlated to high predation or low predation groups, this suggests that individual specialization can occur, but is not necessarily repeatable across similar environments and may not reflect local adaptation of populations. While local adaptation is present in other physical and behavioral traits, it is likely that a generalist approach to feeding is more advantageous for guppies at both the individual and population levels.
