Table 5.

Total short-chain fatty acid concentrations (mM) in the three gut regions of Panaque cf. nigrolineatus “Marañon”, P. nocturnus, Pterygoplichthys disjunctivus, and Hypostomus pyrineusi

Gut Region	P. cf. n. “Marañon”	P. nocturnus	Pt. disjunctivus	H. pyrineusi
Proximal	2.95 ± 0.65	1.50 ± 0.23	2.44 ± 0.41	1.00 ± 0.16a
Mid	2.85 ± 1.40	1.94 ± 0.39	2.40 ± 0.44	3.20 ± 0.79b
Distal	2.10 ± 0.33	1.65 ± 0.32	3.50 ± 0.68	2.01 ± 0.40ab
	F 2,17 = 0.26	F 2,17 = 0.48	F 2,17 = 1.28	F 2,14 = 4.55
	P = 0.77	P = 0.63	P = 0.31	P = 0.03

Values are mean (±SEM). Comparisons of SCFA concentrations among gut regions within a species were made with ANOVA, with differences considered significant at P = 0.05. If significant differences were detected with ANOVA, this was followed by a Tukey’s HSD multiple comparison test with a family error rate of P = 0.05. Those values sharing a superscript letter are not significantly different. Sample sizes were as follows: P. cf. n. “Marañon”, n = 6; P. nocturnus, n = 6; Pt. disjunctivus, n = 10; H. pyrineusi, n = 5. Acetate:propionate:butyrate ratios for total SCFAs were as follows: P. cf. n. “Marañon” = 62:23:15; P. nocturnus = 44:31:25; Pt. disjunctivus = 70:16:14; H. pyrineusi = 52:28:20