title: Refuge from predation, the benefit of living in an extreme acidic environment?
abstract: Organisms living in extreme habitats require costly adaptations to cope with these conditions. Among the suggested potential benefits that trade off these costs is refuge from predation. To study these interactions in extreme environments, samples were taken in the cave Cueva de Villa Luz, Tabasco, Mexico, where more than 32 subterranean springs, some H(2)S rich, rise from the floor. Hydrogen sulfide gas plus oxygen is absorbed by freshwater, and oxidation forms concentrated sulfuric acid. Snottites, whitish hollow mucous tubes, hang from the ceiling of the cave. Fluid drops from these snottites were recorded as having pH values of 0-3. We report the discovery of a new species of nematode that thrives in the highly acidic environment of the snottite. Micro CT scan of snottites reveals a complex interaction between the acidic snottite, nematodes, and abundant nematode-eating mites. The nematode adaptation to low pH probably protects them against mite predation, for which nematodes are most likely the most important source of carbon in this sulfur-driven ecosystem.
authors.affiliation: Ghent University, Department of Biology, Ledeganckstraat 35, Ghent, Belgium. GBorgonie@gmail.com
authors.forename: Gaëtan
authors.initials: G
authors.lastname: Borgonie
authors.forename: Manuel
authors.initials: M
authors.lastname: Dierick
authors.forename: Wouter
authors.initials: W
authors.lastname: Houthoofd
authors.forename: Maxime
authors.initials: M
authors.lastname: Willems
authors.forename: Patric
authors.initials: P
authors.lastname: Jacobs
authors.forename: Wim
authors.initials: W
authors.lastname: Bert
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D001483:Base Sequence; D057486:Carbon Cycle; D020378:Confined Spaces; D006863:Hydrogen-Ion Concentration; D008800:Mexico; D008925:Mites / Q000502:physiology*; D008969:Molecular Sequence Data; D009348:Nematoda / Q000033:anatomy & histology / Q000145:classification / Q000502:physiology*; D010802:Phylogeny; D011235:Predatory Behavior; D013464:Sulfuric Acids / Q000032:analysis
chemical_list: D013464:Sulfuric Acids; C033158:sulfuric acid