Table 2. Frequency of occurrence and volumetric contributions of different food items consumed by (A) Labeobarbus intermedius (n = 141), (B) Labeobarbus nedgia (n = 92) and (C) Labeo forskalii (n = 46) in the upper Blue Nile River

Food items	Frequency of occurrence		Volumetric analysis
	Frequency	%	Volume (mL)	%
(A)
Phytoplankton	140	99.3	1,130.0	61.3
Green algae	94	66.7	612.2	33.2
Blue-green algae	81	57.4	293.7	15.9
Diatoms	90	63.8	224.1	12.2
Insects	108	76.6	334.1	18.1
Ephemeroptera	31	22.0	75.4	4.1
Coleweoptera	20	14.2	26.0	1.4
Plecoptera	5	3.5	8.2	0.4
Ashinidae	1	0.7	0.5	0.04
Anisoptera	1	0.7	2.7	0.1
Zygoptera	4	2.8	10.9	0.6
Diptera	13	9.2	25.0	1.4
Hemiptera	21	14.9	28.1	1.5
Chironomid larvae	102	72.3	135.0	7.3
Tricoptera	10	7.1	22.2	1.2
Detritus	123	87.2	148.7	8.1
Macrophyte seed	28	19.9	83.0	4.5
Macrophytes	65	46.1	74.8	4.1
Sand grains	6	4.3	27.8	1.5
Unidentified items	17	12.1	18.5	1.0
Nematodes	18	12.8	15.4	0.8
Aquatic flatworms	18	12.8	15.4	0.8
Fish scale	10	7.1	9.2	0.5
Zooplankton	6	4.3	2.7	0.1
Protozoa	1	0.7	0.7	0.0
Cladocerans	5	3.5	2.0	0.1
(B)
Insects	84	91.3	288.35	37.4
Ephemeroptera	47	51.1	94.01	12.2
Coleoptera	17	18.5	20.205	2.6
Hemiptera	33	35.9	47.27	6.1
Chironomid larvae	68	73.9	82.39	10.7
Diptera	16	17.4	33.445	4.3
Odonata	2	2.2	0.435	0.1
Plecoptera	1	1.1	0.135	0.0
Tricoptera	5	5.4	10.46	1.4
Phytoplankton	83	90.2	267.896	34.7
Blue-green algae	63	68.5	109.47	14.2
Green algae	41	44.6	89.561	11.6
Diatoms	41	44.6	68.865	8.9
Macrophyte seed	22	23.9	55.87	7.2
Sand grains	25	27.2	52.245	6.8
Detritus	72	78.3	48	6.2
Macrophytes	49	53.3	36.432	4.7
Nematodes	27	29.3	13.143	1.7
Aquatic flatworms	28	30.4	13.143	1.7
Gastropods	1	1.1	6.3	0.8
Cerithidea decollata	1	1.1	6.3	0.8
Fish scale	4	4.3	1.945	0.3
Unidentified items	3	3.3	0.978	0.13
Zooplankton	3	3.3	0.825	0.11
Cladocerans	2	2.2	0.39	0.1
Protozoa	1	1.1	0.435	0.1
(C)
Mud	46	100.0	217.205	57.7
Phytoplankton	39	84.8	149.94	39.8
Blue-green algae	36	78.3	130.685	34.7
Diatoms	9	19.6	15.28	4.1
Green algae	2	4.3	3.975	1.1
Nematodes	12	26.1	9.355	2.5
Aquatic flatworms	12	26.1	9.355	2.5
Zooplankton	1	2.2	0.2	0.1
Cladocerans	1	2.2	0.2	0.1