Table 3. Relative contributions of different food items in the diet of (A) Labeobarbus intermedius, (B) Labeobarbus nedgia and (C) Labeo forskalii during the post-rainy and dry seasons in the upper Blue Nile River

Food items	Frequency of occurrence (%)		Volumetric contribution (%)
Food items	Post-rainy season	Dry season	Post-rainy season	Dry season
(A)
Insects	95.7^a	65.3^a	38.2^b	10.7^a
Ephemeroptera	50.0	14.7	10.3	1.8
Coleoptera	37.0	10.5	3.0	0.8
Plecoptera	10.9	-	1.6	-
Hemiptera	19.6	12.6	1.7	1.5
Anisoptera	2.2	-	0.5	-
Ashinidae	-	1.1	-	0.04
Diptera	17.4	5.3	4.5	0.2
Zygoptera	8.7	-	2.2	-
Chironomid larvae	73.9	65.3	10.8	6.0
Tricoptera	13.0	5.3	3.6	0.3
Phytoplankton	82.6^a	96.8^a	37.6^a	70.0^b
Green algae	65.2	67.4	30.9	34.1
Blue-green algae	19.6	73.7	3.1	20.7
Diatoms	54.3	70.5	3.6	15.3
Detritus	80.4^a	94.7^a	8.9^a	7.8^a
Macrophyte seed	26.1^a	16.8^a	5.9^a	4.0^a
Macrophytes	50.0^a	45.3^a	6.0^a	3.3^a
Sand grains	10.9^a	4.2^a	1.6^a	1.5^a
Unidentified items	-	18.9^b	-	1.4^b
Nematodes	15.2^a	15.8^a	0.8^a	0.9^a
Aquatic flatworms	15.2	15.8	0.8	0.9
Zooplankton	13.0^b	-	0.6^a	-
Cladocerans	10.9	-	0.4	-
Protozoa	2.2	-	0.1	-
Fish scale	13.0^a	5.3^a	0.4^a	0.5^a
(B)
Insects	96.4^a	87.7^a	51.0^a	31.3^a
Ephemeroptera	42.9	53.8	12.8	11.9
Coleoptera	25.0	15.4	6.4	0.9
Hemiptera	28.6	38.5	6.0	6.2
Chironomid larvae	75.0	72.3	16.0	8.3
Diptera	17.9	16.9	6.5	3.4
Plecoptera	3.6	-	0.06	-
Odonata	-	3.1	-	0.1
Tricoptera	10.7	4.6	3.3	0.5
Phytoplankton	78.6^a	92.3^a	15.6^a	43.3^a
Green algae	35.7	47.7	7.76	13.3
Blue-green algae	39.3	81.5	4.7	18.4
Diatoms	32.1	49.2	3.06	11.5
Macrophyte seed	21.4^a	24.6^a	11.1^a	5.5^a
Detritus	67.9^a	81.5^a	10.7^a	4.2^a
Macrophytes	42.9^a	56.9^a	5.1^a	4.5^a
Sand grains	21.4^a	29.2^a	3.2^a	8.3^a
Nematodes	35.7^a	27.7^a	2.1^a	1.5^a
Aquatic flatworms	35.7	27.7	2.1	1.5
Gastropods	-	1.5^a	-	1.2^a
Cerithidea decollata	-	1.5	-	1.2
Fish scale	10.7^b	-	0.8^a	-
Zooplankton	3.6^a	3.1^a	0.2^a	0.1^a
Cladocerans	-	3.1	-	0.1
Protozoa	3.6	-	0.2	-
Unidentified items	3.6^a	3.1^a	0.1^a	0.1^a
(C)
Mud	94.1^a	96.6^a	90.3^b	37.3^a
Nematodes	64.7^b	6.9^a	5.6^a	0.6^a
Aquatic flatworms	64.7	6.9	5.6	0.6
Phytoplankton	52.9^a	100.0^b	4.1^a	62.1^b
Green algae	-	6.9	-	1.7
Blue-green algae	52.9	100.0	4.1	53.8
Diatoms	-	72.4	-	6.6
Zooplankton	-	3.4^a	-	0.1^a
Cladocerans	-	3.4	-	0.1

Values of respective food categories under the same category given different superscript letters are significantly different (χ², p < 0.05).