Feeding pattern of the African big barb Labeobarbus intermedius (Rüppel, 1836) (Pisces: Cyprinidae) in Ribb Reservoir, Lake Tana Sub-basin, Ethiopia

Figures & data

Figure 1. Study area map shows sampling sites at the Ribb Reservoir, Ethiopia.

Figure 2. The mean relative geometric index importance (%GIIi) in the diet of L. intermedius (n = 302) from Ribb Reservoir (DT- detritus; MD-mud, PT–Phytoplankton; ZP–Zooplankton; DT– detritus; SAG-sand grain; and OC-ostracod. Dotted vertical lines separate the different grades of favorite food items).

Table 1. Proportions of different food items in the diet of L. intermedius (n = 302) in Ribb Reservoir, Ethiopia.

Food items	%Oi	%Vi	%IoP	%GIIi
Zooplankton	100	3.9	4.5	39.2
Cladocera	64.2	2.7	2.0	25.3
Copepod	19.2	1.2	0.3	7.7
Rotifer	2.0	0.06	0.01	0.8
Phytoplankton	98.3	2.8	3.2	38.2
Blue-green algae	67.9	1.3	1.0	26.1
Green algae	52.9	0.4	0.3	20.1
Euglenoids	57.9	1.1	0.7	22.3
Detritus	98.7	61.6	69.5	60.5
Insects	17.5	1.5	0.3	7.2
Ostracods	3.3	1.0	0.03	1.6
Sand particles	20.9	1.2	0.3	8.3
Macrophytes	4.7	0.3	0.02	1.9
Mud	79.8	24.4	22.3	39.3

Percentage frequency of occurrence (%Qi), percentage of volumetric contribution (%Vi), percentage index of preponderance (%IoP) and Geometric Index of Importance (GIIi).

Figure 3. The size class variation in the diet of L. intermedius in Ribb Reservoir, Ethiopia.

Table 2. The mean relative importance of food items in the diet of L. intermedius (n = 229) during the dry season in Ribb Reservoir, Ethiopia.

Food items	%Oi		%Vi		%IoP		%GIIi
	Dry	Wet	Dry	Wet	Dry	Wet	Dry	Wet
Detritus	98.3	97.2	47.8	75.6	51.8	92.9	52.2	72.0
Zooplankton	87.3	13.7	4.7	1.8	4.5	0.3	32.9	6.5
Cladocera	83.9	–	3.6	–	3.3	–	31.3	–
Copepod	20.4	13.1	1.4	1.8	0.3	0.3	7.8	6.2
Rotifer	1.7	–	0.08	–	0.00	–	0.6	–
Phytoplankton	75.2	24.6	1.2	1.3	1.0	0.4	27.3	10.8
Blue-green algae	34.8	6.8	0.6	0.2	0.25	0.01	12.6	2.9
Green algae	30.4	–	0.3	–	0.1	–	11.0	–
Euglenoids	10	17.8	0.3	1.1	0.03	0.2	3.7	7.9
Mud	97.8	13.7	32.4	1.1	34.9	0.2	46.5	6.2
Insect	73.9	41.4	7.9	11.4	6.4	6.0	29.2	22.0
Ostracods	17	–	0.5	–	0.1	–	6.3	–
Sand particles	30.4	–	2.3	–	0.8	–	11.7	–
Macrophytes	21.7	5.4	1.7	3.7	0.4	0.3	8.4	3.8

Percentage frequency of occurrence (%Qi), percentage of volumetric contribution (%Vi), percentage index of preponderance (%IoP) and Geometric Index of Importance (GIIi).

Availability of data

All the data sets used in this manuscript are accessible to the corresponding author via a reasonable request.