Table 2. Relative percentage contributions (%) of different food items in the diet of Oreochromis niloticus during dry (n = 134) and wet (n = 239) season from Lake Tinishu Abaya

Food items	Frequency of occurrence (%)		Volumetric contribution (%)
	Dry season	Wet season	Dry season	Wet season
Phytoplankton	98.51)	91.61)	56.51)	33.01)
Blue green algae	97.8	77.8	28.0	14.4
Green algae	96.3	69.9	9.0	12.0
Diatom	69.4	77.0	4.4	4.7
Euglenoids	6.0	5.9	0.7	0.5
Others	78.4	32.6	14.4	1.3
Zooplankton	52.21)	82.41)	22.2	17.01)
Copepods	29.9	59.0	3.3	4.4
Cladoceran	8.2	45.2	0.7	10.6
Rotifers	82.8	58.6	18.2	2.0
Macrophytes	20.2	72.81)	13.8	30.61)
Detritus	56.71)	84.11)	11.6	15.5
Insects	8.2	28.0	16.91)	0.8
Diptera	30.6	6.7	4.1	0.8
Ephemeroptera	24.6	2.9	2.7	0.7
Coeoptera	9.7	0.0	2.7	0.0
Hemiptera	33.6	0.8	2.0	0.4
Plecoptera	6.0	0.0	2.0	0.0
Nematods	2.2	6.7	0.1	0.1
Ostracods	6.7	17.6	0.9	2.9
Fish scales	4.5	2.1	0.2	0.2

The sum of the major categories of food items adds up to 100% in volumetric analysis.
The food items which significantly contributed to the diet of the fish in the two seasons.