The effects of population structure on crayfish aggression


Meeting Abstract

P2-242  Friday, Jan. 5 15:30 – 17:30  The effects of population structure on crayfish aggression CURTIS, KM*; MOORE, PA; MARTIN III, AL; Saginaw Valley State University; Bowling Green State Universiy; Saginaw Valley State University kmcurti1@svsu.edu

Animals readily participate in agonistic interactions that often allow them to secure or maintain access to necessary resources. Crayfish are known to fight vigorously when first introduced, with aggressive behaviors decreasing in frequency and duration as the population stabilizes. These interactions often result in dominant and subordinate relationships developing between individuals in a population. In paired interactions between crayfish of different sizes, the large animal will become dominant while he small animal will behave as a subordinate. However, populations of crayfish are more complex, contain more conspecifics, and are more difficult to assess. Mutual- and self-assessment are ways in which animals evaluate conspecifics within a population; this assessment will influence the behaviors of the focal animal as it encounters conspecifics in agonistic bouts. Some theoretical models have examined assessment strategies and aggression within populations in relation to resource value, but more empirical evidence is required to support these models. To begin to address this issue, we examined the influence of crayfish population structure on aggression with a constant number (4) of identical shelters presented to each group. Populations of animals (4 large, 4 small, 3 small vs. 1 large, 2 small vs. 2 large, or 1 small vs. 3 large) are recorded for 24-hour trials to determine fight duration and outcome. The fight duration data collected from these trials will provide strong evidence for the influence population structure has on aggression in the presence of a consistent resource (shelters). This study along with future studies on resource value will provide empirical evidence to better understand how resources and assessment strategies collectively influence the intricacies of population structure.

the Society for
Integrative &
Comparative
Biology