Resource Partitioning between Two Piranhas (Serrasalmus gibbus and Serrasalmus rhombeus) in an Amazonian Reservoir

Table 1

Frequency of occurrence (FO), volumetric frequency (VF), and index of feeding importance () of the items encountered in the stomach contents of the S. gibbus and S. rhombeus specimens captured in the dry and flood seasons in the Coaracy Nunes reservoir in Ferreira Gomes, Amapá (Brazil).

Species	Food item	Flood			Dry			test
		FO (%)	VF (%)		FO (%)	VF (%)	IA	FO
S. gibbus	Fish	65.517	22.014	0.9671	96.429	37.118	0.9588
	Crustacean	10.345	2.510	0.0174	10.714	3.857	0.0111
	Insect	20.689	1.089	0.0151	14.286	0.843	0.0032
	Plant	3.448	0.138	0.0003	25.000	4.007	0.0268
	Microcrustacean	3.448	0.055	0.0001	3.571	0.075	0.0001
S. rhombeus	Fish	80.000	0.906	0.9747	100.000	1.000	1.000
	Crustacean	20.000	0.089	0.0239	0.000	0.000	0.000
	Insect	20.000	0.004	0.0011	0.000	0.000	0.000
	Microcrustacean	20.000	0.001	0.0003	0.000	0.000	0.000

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