Table 3. Cell-specific incorporation of ¹³C-labeled bicarbonate by the Sulfurovum epibionts on S. crosnieri seta in the presence and the absence of thiosulfate according to FISH–Nano-SIMS.

Tracer	Location	Average 13C/12C	Enrichment (%)
	1*	0.428±0.086	2713±588
	2*	0.292±0.058	2019±435
NaH13CO3	3*	0.394±0.079	2551±552
+	4†	0.135±0.027	1012±225
thiosulfate	5†	0.082±0.016	608±143
	6†	0.010±0.002	−10±20
	7†	0.011±0.002	−5±20
	8†	0.010±0.002	−10±20
	1*	0.009±0.002	−15±20
	2*	0.010±0.002	−10±20
NaH13CO3	3*	0.011±0.002	−5±20
	4*	0.009±0.002	−15±20
	5*	0.009±0.002	−15±20
	6*	0.010±0.002	−10±20
–	Control epibiont cells	0.01077	–

The percent enrichment was estimated using the average ¹³C/¹²C ratio of bulk organic carbon of the epibiotic microbial community before the experiment shown in Table 2.

^*The filamentous cells were identified as Sulfurovum members by FISH.

^†The filamentous cells were not identified as the Sulfurovum members by FISH.