TABLE 2.

Pool sizes of selected metabolites in the different gut sections of Cubitermes spp. and the injected amounts of the corresponding radiolabeled tracers^a

Metabolite	Pool size (nmol section−1)b						Injected amt
	C. umbratus			C. orthognathus			nmol	Bq
	P1 (1.55 ± 0.23 μl)	P3/4a (0.97 ± 0.16 μl)	P4b (0.32 ± 0.16 μl)	P1 (0.76 ± 0.19 μl)	P3/4a (0.54 ± 0.15 μl)	P4b (0.12 ± 0.02 μl)
Acetate	6.80 ± 0.39	5.86 ± 0.68	0.73 ± 0.06	3.30 ± 0.07	3.83 ± 0.06	0.35 ± 0.12	0.21	61
CO2c	26.0 ± 1.5	22.4 ± 0.3	13.2 ± 2.1	13.1 ± 0.9	11.0 ± 0.2	6.9 ± 1.1	1.50	315
Formate	0.03 ± 0.03	<0.01	0.06 ± 0.05	<0.01	0.09 ± 0.08	<0.01	0.17	340

^aThe average volume of the sections (given in parentheses above) was determined by geometric approximation. A complete data set including all metabolites will be published elsewhere (36). For definitions of the sections, see Fig. 1 in the companion paper (33). 

^bValues are means (± standard deviations) of three independent values, determined as described elsewhere (35). 

^cTotal dissolved inorganic C (CO₂ plus HCO₃⁻ plus CO₃²⁻).