Meeting Abstract

9.1  Monday, Jan. 4  Anchialine Cave Ecology: A Multi-Disciplinary Approach PAKES, M. J. *; WRIGHTON, K. C. ; THRASH, J. C.; SANTIS, T. D. ; ANDERSON, G. L. ; ILIFFE, T. M. ; COATES, J. C. ; LINDBERG, D. R. ; CALDWELL, R. L. ; Univ of California, Berkeley; Univ of California, Berkeley; Univ of California, Berkeley; Lawrence Berkeley National Laboratory; Lawrence Berkeley National Laboratory; Texas A&M, Galveston; Univ of California, Berkeley; Univ of California, Berkeley; Univ of California, Berkeley pakes@berkeley.edu

In anchialine caves, a marine layer flows beneath one or more layers of less saline water. Water exchange with nearby oceans is severely restricted, creating stable physico-chemical gradients often characterized by anoxia and high sulfide levels. The resulting unique environment has lead to the evolution of endemic fauna, including the ancestral crustacean class Remipedia. Little is known about basic anchialine ecology; many questions remain about the structure and stability of their microbial communities and isolated bacteria have not been reported in the literature. We introduce a multidisciplinary approach to examining the ecology of anchialine caves in Quintana Roo, Mexico. We aimed to assess I) whether chemoautotrophic bacteria and archaea were present in the cave sediment and water column, and II) whether such microorganisms were major contributors to the food web. Successful isolation of anaerobic chemoautotrophic bacteria from cave sediment and subsequent community analysis of cave microorganisms using oligonucleotide phylogenetic microarrays (PhyloChips) confirmed the presence of these organisms. Stable isotope analysis of carbon and nitrogen isotope ratios revealed spatial variation in trophic dynamics between caves. These analyses support microbial input into the diets of some but not all cave animals studied. In situ behavioral studies have not yet been reported in the literature and here we present preliminary videotape analyses of individuals feeding on shrimp in their natural environment. Through these varied approaches to anchialine study, we have a better understanding of the micro and marcofaunal interactions of this ecosystem.