Table 2. Frequency of occurrence (Qi), volumetric contribution (Vi), index of preponderance (IOP) and percentage contribution of various food items of Oreochromis niloticus (n = 226) in Lake Shala

Food items		Qi	%Qi	Vi	%Vi	IOPa	IOP%
Phytoplankton	Bacillariophyceae	201	88.9	211.9	72.3	24.9	91.3
	Nitzschia spp.	198	87.6	89.04	30.4	4.7	17.8
	Navicula spp.	176	77.9	27.1	9.3	1.3	14.4
	Melosira spp.	121	53.5	15.4	5.3	0.5	9.8
	Achnanthes spp.	36	15.9	2.6	0.9	0.02	2.9
	Anomoeoneis spp.	181	80.1	36.7	12.5	1.8	15.1
	Cyclotella spp.	52	23.0	7.1	2.4	0.1	4.2
	Epithemia spp.	43	19.0	4.8	1.6	0.05	3.5
	Rhopalodia spp.	71	31.4	13.4	4.6	0.3	6.0
	Frustulia spp.	86	38.1	7.9	2.7	0.18	6.9
	Campylodiscus spp.	41	18.1	1.91	0.7	0.02	3.2
	Amphora spp.	36	15.9	1.4	0.5	0.01	2.8
	Surullia spp.	28	12.4	0.81	0.3	0.006	2.2
	Flagillaria spp.	31	13.7	0.94	0.3	0.008	2.4
	Cymbella spp.	48	21.2	1.1	0.4	0.014	3.8
	Gomphonema spp.	25	11.1	1.7	0.6	0.011	2.0
	Cyanophyceae	64	28.3	9.4	3.2	0.4	1.3
	Anabaena spp.	35	15.5	1.8	0.6	0.02	2.8
	Planktolyngbya spp.	51	22.6	3.8	1.3	0.05	4.1
	Phormidium spp.	46	20.4	3.1	1.1	0.04	3.7
	Spirulina spp.	29	12.8	0.7	0.2	0.01	2.3
Zooplankton	Rotifera	71	31.4	24.8	8.5	0.5	6.2
	Copepoda	48	21.2	13.6	4.6	0.2	4.1
	Cladocera	24	10.6	4.1	1.4	0.03	2.0