title: Hydrogen sulfide, bacteria, and fish: a unique, subterranean food chain.
abstract: Photoautotrophs are generally considered to be the base of food webs, and habitats that lack light, such as caves, frequently rely on surface-derived carbon. Here we show, based on analysis of gut contents and stable isotope ratios of tissues (13C:12C and 15N:14N), that sulfur-oxidizing bacteria are directly consumed and assimilated by the fish Poecilia mexicana in a sulfide-rich cave stream in Tabasco state, Mexico. Our results provide evidence of a vertebrate deriving most of its organic carbon and nitrogen from in situ chemoautotrophic production, and reveals the importance of alternative energy production sources supporting animals in extreme environments.
authors.affiliation: Department of Wildlife and Fisheries Sciences, Texas A&M University, 2258 TAMU, College Station, Texas 77843, USA. roackat@gmail.com
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Roach
authors.forename: Michael
authors.initials: M
authors.lastname: Tobler
authors.forename: Kirk O
authors.initials: KO
authors.lastname: Winemiller
mesh_terms: D000818:Animals; D059552:Caves; D005247:Feeding Behavior; D020387:Food Chain; D006862:Hydrogen Sulfide / Q000378:metabolism*; D011036:Poecilia / Q000378:metabolism*; D045483:Rivers; D016999:Sulfur-Reducing Bacteria / Q000378:metabolism*
chemical_list: D006862:Hydrogen Sulfide