PARENT SESSION
Oral Session # 10: Predator-Prey Ecology I: Terrestrial I: Theory and Cues.
Presiding: A Liebold
Monday, August 4. 8:00 AM to 11:30 AM, SITCC Meeting Room 202.

Microbial chemical defense of carcasses: Testing Janzen's "Why Fruits Rot, Seeds Mold, and Meat Spoils" hypothesis.

Burkepile, Deron^*,1, Parker, John¹, Woodson, Brock¹, Hay, Mark¹, ¹ Georgia Tech, Atlanta, Georgia, USA

ABSTRACT- Interactions of microbes with higher organisms are often described as mutualistic (e.g., gut symbionts) or parasitic (e.g., pathogens), but rarely as competitive. Microbes that colonize rich food sources such as fruits and animal carcasses, however, should be selected to defend their food, and thus themselves, from being eaten by larger consumers. We investigated the possibility that marine microorganisms colonize and protect fish carcasses from marine scavengers. Rotten carrion attracted fewer consumers than fresh carrion and was unpalatable to some consumers. In feeding assays, chemical extracts from rotten carrion were unpalatable. Microbes probably mediate the unpalatability of carrion given that carrion "rotted" in an antibiotic solution was palatable to consumers. Thus, microbially-produced chemicals are probably responsible for the chemical repugnance of rotten carrion. Our data support Janzen's (1977) untested hypothesis that, 'meat spoils because that is the way microbes compete with bigger organisms.' Because microbes are ubiquitous components of communities and produce a variety of bioactive secondary metabolites, microbial defense of resources from larger organisms may be an under-appreciated feature of community dynamics.

Key words: competition, chemical defense, scavengers