Fig. 2.

Total (intestinal fluid + microbial extract) amylolytic, laminarinase, cellulase, and xylanase activities in three regions of the intestine of Panaque cf. nigrolineatus “Marañon” (Pm), P. nocturnus (Pn), Pterygoplichthys disjunctivus (Ptd), and Hypostomus pyrineusi (Hp). Values are means and error bars represent SEM. Intraspecific comparisons of each enzyme among gut regions were made with ANOVA followed by a Tukey’s HSD with a family error rate of P = 0.05. Regional activity levels for a specific enzyme and species that share a letter are not significantly different. No letters above the gut regions for a particular enzyme indicate that there are no differences in activity among the intestinal regions for that species. Interspecific comparisons among species were not made