Acquisition of a Novel Sulfur-Oxidizing Symbiont in the Gutless Marine Worm Inanidrilus exumae.

Gutless phallodrilines are marine annelid worms without a mouth or gut, which live in an obligate association with multiple bacterial endosymbionts that supply them with nutrition. In this study, we discovered an unusual symbiont community in the gutless phallodriline that differs markedly from the microbiomes of all 22 of the other host species examined. Comparative 16S rRNA gene sequence analysis and fluorescence hybridization revealed that harbors cooccurring gamma-, alpha-, and deltaproteobacterial symbionts, while all other known host species harbor gamma- and either alpha- or deltaproteobacterial symbionts.

Limnodrilus sulphurensis n. sp., from a sulfur cave in Colorado, USA, with notes on the morphologically similar L. profundicola (Clitellata, Naididae, Tubificinae).

A new species of the tubificine genus Limnodrilus is described and COI barcoded from Sulphur Cave and associated springs in Colorado, USA. The habitats are characterized by high sulfide concentrations. The new species, L.

Widespread occurrence of an intranuclear bacterial parasite in vent and seep bathymodiolin mussels.

Many parasitic bacteria live in the cytoplasm of multicellular animals, but only a few are known to regularly invade their nuclei. In this study, we describe the novel bacterial parasite "Candidatus Endonucleobacter bathymodioli" that invades the nuclei of deep-sea bathymodiolin mussels from hydrothermal vents and cold seeps. Bathymodiolin mussels are well known for their symbiotic associations with sulfur- and methane-oxidizing bacteria.

Survival in an extreme habitat: the roles of behaviour and energy limitation.

Extreme habitats challenge animals with highly adverse conditions, like extreme temperatures or toxic substances. In this paper, we report of a fish (Poecilia mexicana) inhabiting a limestone cave in Mexico. Several springs inside the cave are rich in toxic H(2)S.

Molecular and morphological characterization of the association between bacterial endosymbionts and the marine nematode Astomonema sp. from the Bahamas.

Marine nematode worms without a mouth or functional gut are found worldwide in intertidal sandflats, deep-sea muds and methane-rich pock marks, and morphological studies show that they are associated with endosymbiotic bacteria. While it has been hypothesized that the symbionts are chemoautotrophic sulfur oxidizers, to date nothing is known about the phylogeny or function of endosymbionts from marine nematodes. In this study, we characterized the association between bacterial endosymbionts and the marine nematode Astomonema sp.