Table 2.

Summary of ANOVA and t test^a statistics for intraspecific comparisons of digestive enzyme activities among different regions of the intestine in four species of loricariid catfishes

Enzyme	P. cf. n. “Marañon” (6)	P. nocturnus (6)	Pt. disjunctivus (10)	H. pyrineusi (5)
Amylolytic	F 2,17 = 28.30	F 2,17 = 23.34	F 2,29 = 8.56	F 2,14 = 51.68
	P < 0.001	P < 0.001	P = 0.001	P < 0.001
Laminarinase	F 2,17 = 17.66	t = 2.68	F 2,29 = 13.02	t = 1.96
	P < 0.001	P = 0.023	P < 0.001	P = 0.086
Cellulase	F 2,17 = 0.20	F 2,17 = 0.74	F 2,29 = 11.11	t = 3.86
	P = 0.818	P = 0.492	P < 0.001	P = 0.018
Xylanase	F 2,17 = 6.56	F 2,17 = 0.81	F 2,29 = 3.04	t = 3.18
	P = 0.009	P = 0.463	P = 0.065	P = 0.013
Trypsin	F 2,17 = 23.59	F 2,17 = 208.28	F 2,29 = 9.03	F 2,14 = 36.21
	P = 0.009	P < 0.001	P = 0.001	P < 0.001
Lipase	F 2,17 = 34.80	F 2,17 = 61.79	F 2,29 = 0.74	F 2,14 = 22.06
	P < 0.001	P < 0.001	P = 0.485	P < 0.001

^aIf only two values were compared, t test was used instead of ANOVA. For example, comparisons of laminarinase activities in P. nocturnus and H. pyrineusi were only made among the PI and MI with t test because these species lacked laminarinase activity in their distal intestines. Sample sizes in parentheses following species names. Actual enzyme activity data are presented in Fig. 2 for amylase, laminarinase, cellulase, and xylanase, and in Supplemental Fig. 1 (see online version) for trypsin and lipase