Table 1.

Classification and general features of Candidatus Thioglobus thermophilus, the Bathymodiolus thermophilus gill endosymbiont, according to the MIGS recommendations [42]

MIGS ID	Property	Term	Evidence code a
	Classification	Domain Bacteria	TAS [43]
		Phylum Proteobacteria	TAS [44]
		Class Gammaproteobacteria	TAS [45]
		Order Unclassified	NAS
		Family Unclassified, S-oxidizing symbionts	TAS [46]
		Genus Candidatus Thioglobus	TAS [25]
		Species Candidatus Thioglobus thermophilus	TAS [25]
		(Type) strain NA	NAS
	Gram stain	Negative	TAS [18]
	Cell shape	Coccoid or short rods	TAS [9], IDA
	Motility	Non-motile inside the host; a putative free-living stage of the symbiont is likely motile, but no direct evidence exists	NAS
	Sporulation	Unknown
	Temperature range	4 °C - 14 °C (shows psychrophilic growth characteristics)	TAS [10]
	Optimum temperature	Unknown
	pH range; Optimum	6.9–8.0; unknown	TAS [47]
	Carbon source	CO2 (autotroph)	TAS [10, 11, 48, 49]
	Energy source	H2S and S2O3 2− (chemotroph)	TAS [10, 49]
	Terminal electron acceptor	O2, NO3 2−	TAS [11]
MIGS-6	Habitat	Intracellular endosymbiont of marine bivalve inhabiting hydrothermal vents	IDA
MIGS-6.3	Salinity	35.42 PSU	IDA
MIGS − 22	Oxygen	Aerobic (facultative)	TAS [11]
MIGS-15	Biotic relationship	Symbiont	TAS [10, 11]
MIGS-14	Pathogenicity	Non-pathogenic	NAS
MIGS-4	Geographic location	East Pacific Rise (EPR) 9°N	IDA
MIGS-5	Sample collection	January 2014	IDA
MIGS-4.1	Latitude	9° 50.39′ N	IDA
MIGS-4.2	Longitude	104° 17.49′ W	IDA
MIGS-4.3	Altitude	-2511 m	IDA

^aEvidence codes - IDA Inferred from Direct Assay, TAS Traceable Author Statement (i.e., a direct report exists in the literature), NAS Non-traceable Author Statement (i.e., not directly observed for the living, isolated sample, but based on a generally accepted property for the species, or anecdotal evidence). These evidence codes are from the Gene Ontology project [50]