Table 3. Frequency of occurrences, volumetric contributions, and index of the preponderance of various food items in the diet of Oreochromis niloticus from Lake Hawassa (n = 959)

	Frequency of occurrences (FO)		Volumetric contribution (Vol)		Index of preponderance (IP)
Food Item	FO	%FO	Vol	%Vol	IP	%IP
Phytoplankton’s	918*	95.72*	3,284.43*	88.20*	8,442.79*	96.60*
Diatom	761	79.35	781.95	21.00	1,666.27	19.06
Green Algae	618	64.44	678.43	18.22	1,174.02	13.43
Bluegreen Algae	796	83.00	1,665.75	44.73	3,712.83	42.48
Dinoflagellates	216	22.52	85.69	2.30	51.83	0.59
Euglenoids	729	76.02	72.32	1.94	147.63	1.69
Zooplankton’s	152*	15.85*	62.51	1.68*	26.61*	0.30*
Cladocerans	68	7.09	19.04	0.52	3.69	0.04
Rotifers	62	6.47	25.73	0.69	4.47	0.05
Copepods	42	4.38	17.74	0.48	2.09	0.02
Detritus	298*	31.07*	266.53*	7.16*	222.40*	2.54*
Macrophyte	182*	18.98*	94.23*	2.53*	48.02*	0.55*
Nematode	6*	0.63*	1.60*	0.04*	0.03*	0.00*
Fish Egg	4*	0.42*	11.75*	0.32*	0.13*	0.00*
Digested Muscle	3*	0.31*	2.86*	0.08*	0.02*	0.00*
Total				100.00	8,740.003	100.00

Values are mean represents major food item.