Symbiotic chemoautotrophic bacteria in marine invertebrates from sulphide-rich habitats

Sulphur-oxidising bacteria and haemoglobin in gills of the bivalve mollusc Myrtea spinifera

“…Two large-sized species of bivalve mollusc, abundant around vents, have also O Inter-ResearchIPrinted in F. R. Germany been found to carry similar bacteria in their gills. The bacteria may contribute to the bivalves' nutrition, although these animals do have a normal filter feeding mechanism and a digestive system , Cavanaugh 1983. Animals living in other marine environments with high concentrations of free sulphide, such as sewage outfalls and seagrass beds, also contain symbiotic sulphur bacteria.…”

Occurrence of bacteria in the primary oocytes of vesicomyid clam Calyptogena soyoae

“…Calyptogena soyoae harbors symbiotic bacteria in branchial epithelia (Endow 1988), like other vesicomyld clams such as C. magnifica, C. pacifica and C. elonyata (Cavanaugh 1983, Vetter 1985. These bacteria have been found to be sulfur oxidizers and have been postulated to be important to the nutrit~on of host clams (Felbeck et al 1981, Sakai et al 1987.…”

An overview of chemosynthetic symbioses in bivalves from the North Atlantic and Mediterranean Sea

“…The symbiont cycle may be complex as bacterial shape is variable from coccoid-to rod-shaped, and dividing stages are rarely seen, suggesting strong host control. Carbon is fixed via the Calvin cycle (Cavanaugh, 1983;Cavanaugh et al, 1988), using energy derived from the oxidation of reduced sulfur, most likely through the APS pathway for which they possess enzymes (Kleiner et al, 2012;Stewart and Cavanaugh, 2006). Ammonia is the nitrogen source assimilated via a host-encoded glutamine synthetase (Lee et al, 1999).…”

“…In fact, both bivalves and tube worms (Annelida: Siboglinidae) were shown to harbor chemoautotrophic bacteria in their tissues. These bacteria oxidize reduced sulfur from the fluids, and use the energy acquired to fix inorganic carbon, which is subsequently transferred to their animal host (Cavanaugh, 1983;Rau and Hedges, 1979). Similar, often related, organisms and symbioses were then identified at cold seeps and large organic falls occurring in the deep sea (Pailleret et al, 2007;Paull et al, 1984;Smith and Baco, 2003).…”

“…2). Most frequently they correspond to sulfur-oxidizing (thiotrophic) or, in some species, methane-oxidizing (methanotrophic) Gammaproteobacteria (Cavanaugh, 1983;Cavanaugh et al, 1987;Felbeck et al, 1981;Rau and Hedges, 1979). Dual symbioses involving both sulfur-and methane-oxidizing bacteria simultaneously have been reported (Distel et al, 1995;Fiala-Médioni et al, 2002;Fisher, 1993;Olu et al, 1996).…”