Table 1. Physico-chemical and biological data across the River Niger adjacent to Shagunu Research Station on 20 July 1965 (from White ed.. 1965)
Margin of sandbank | Margin of sandbank | Foge Island Shore | ||||||||
Sampling station No. | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | ||
Position - | metres from west bank | 77 | 117 | 154 | 190 | 240 | 283 | 329 | 375 | 384 |
Flow rate | v.fast | v.fast | fast | fast | v. slow | v. slow | v. fast | fast | ||
Depth (m) | 0.50 | 1.15 | 0.60 | 0.80 | 0.13 | 0.13 | 0.80 | 1.20 | ||
Temperature (°C) | 30.54 | 30.32 | 30.26 | 30.26 | 30.74 | 30.86 | 30.23 | 30.28 | ||
Conductivity (umhos at 20°C) | 63.4 | 63.4 | 63.9 | 63.2 | 64.7 | 66.2 | 62.8 | 63.9 | ||
Oxygen | Supersaturated at all stations | |||||||||
Light | (vertical extinction coefficient/metre) | 7.57 | 8.76 | 8.58 | 7.55 | too shallow to measure | 7.88 | 6.48 | ||
Phytoplankton | (organisms per ml | 1 110 | 1 120 | 1 000 | 1 030 | 1 010 | 1 070 | 940 | 960 | |
(chlorophy11A - mg/l) | 0.0125 | 0.0127 | 0.0117 | 0.0137 | 0.0097 | 0.0117 | 0.0110 | 0.0105 | ||
Bottom algae | (organisms per cm2 | no sample | 500 | 500 | 500 | 54 700 | 42 900 | 500 | no sample | |
(chlorophy11A - ug/cm2) | no sample | 0.002 | 0.002 | 0.002 | 0.941 | 0.645 | 0.002 | no sample |
No differences in temperature, conductivity or oxygen concentration were observed with depth at any site
Table 2. The average chemical composition of the waters at the main sampling stations (from White ed. 1965)
Ca++ (%) | Mg++ (%) | Na+ (%) | K+ (%) | HCO-3 (%) | SO-- (%) | Cl- (%) | |
R. Niger | 10.7 | 8.2 | 16.0 | 8.5 | 54.8 | 0.1 | 1.7 |
R. Swashi | 11.7 | 8.3 | 14.4 | 7.4 | 58.2 | 0.0 | 0.0 |
Tungan Kikwashi | 9.1 | 9.5 | 12.5 | 10.8 | 58.1 | 0.0 | 0.0 |
Kpan pool (bridge 206/1) | 12.5 | 7.6 | 14.5 | 8.4 | 57.0 | 0.0 | 0.0 |
Percentages based on molar concentrations
Table 3. General comparisons among some large African man-made lakes (from Balon and Coche, 1974)
Characteristics | L. Kariba | L. Nasser/Nubia | L. Kainji | L. Volta | L. Kossou2 | |
REFERENCES | Personal data | Entz 1973; Entz & Ramsey 1973 | Henderson 1973 Imevbore 1970 | Entz 1969b; Fao/Undp 1971: Bretschko, pers. comm. | Lessent (pers. comm.) Krzelj (pers. comm.) | |
GEOGRAPHY | Country | Rhodesia-Zambia | Egypt/Sudan | Nigeria | Ghana | Ivory Coast |
Latitude | 16°28'–18°04'S | 23°58'–20°27'N | 9°30'–10°35'N | 6°15'–9°10'N | 7° –8°N | |
Longitude | 26°42'–29 03'E | 30°35'–33°15'E | 4°25–4°45'E | 1°40'W –0°20'E | 5°25'–5°45'W | |
Altitude, m a.s.l. | 485 | 180 | 142 | 85 | 204 | |
Vegetation type | forest + wooden savannah | desert | forest + Guinean savannah | forest + Guinean savannah | forest + Guinean savannah | |
METEOROLOGY | Climate (Köppen) | BSwh' | BWhs | Aw | Amw'-Aw | Amw'-Aw |
Mean air temp. °C | 24.3–24.7 | (24) | (26.5) | 26.4–27.8 | 26.3 | |
Abs. min temp. °C | 2.8 | 5 | (mean) 14.1 (Dec. + Feb.) | 20(mean 25.7) | 13 (mean 21.1) | |
Abs. max temp °C | 40.6 | 48 | (mean) 39.0 (Mar.–May) | (mean) 28.0 | 40 (mean 31.3) | |
Rainfall year, mm | 610 | - | 660–1352 (May–Sep.) | 890–1712 | 1150–1400 | |
Gross evapor., mm | 2500–3600 | 3824 | 1500–2000 | 1398 | 1500 | |
HYDROLOGY | River catchment | Zambezi | Nile | Niger | Volta (Black-White) | White Bandama |
Area catchment above dam, sq. km | 823 200 | 2 400 000 | 1 600 000 | 394 000 | 32 400 | |
Annual inflow,106 cum | 39 000(recent 47 300) | 84 000 | 80 000 | 37 000 | 5 680 | |
Avg. ann. inflow, cu. m. sec-1 | 566–2516 (1200) | 450–9 500 | (800–2000) | 1 167 | 57–320 (179) | |
River flow ratio (min:max) | 1:13 | 1:17 | 1:16 | - | 1:5.6 | |
River flood season | Mar.–Apr | Aug.–Oct. | (White floods (Jul.–Sep.)) (Black flood (Dec.–Feb.)) | Jul.–Sep. | Sep.–Oct. | |
DAM | Site | Kariba | Aswan | Kainji | Akosombo | Kossou |
Closed in: | December 1958 | May 1964 | August 1968 | May 1964 | February 1971 | |
Normal water level in: | March 1963 | (? 1980) | 1968 | 1968 | (? 1978) | |
Hydro-electric max. capacity, Kw | 1 500 | 2 100 | 960 | 882 | 175.5 | |
MORPHOMETRY1 | Length, km | 277 | 482 | 137 | (1296) | 180 |
Mean breadth, km | 19.4 | 13.0 | 9.3 | 6.8 | 8.9 | |
Area, sq. km | 5364 | 6276 | 1280 | 8845 | 1600 | |
Volume, cu. km | 156 | 158 | 15.8 | 165 | 29.5 | |
Max.depth, m | 93 | 130 | 50 | 75 | 54 | |
Mean depth, m | 29.2 | 25.2 | 12.3 | 18.6 | 18.4 | |
Length shoreline, km | 2164 | 8804 | 720 | ab. 5300 | 3500 | |
HYDROLOGY | Ann. gross evaporation, cu.km | 4.2 | 24 | 1.9–2.56 | 12.4 | 2.4 |
Water level max. m | 489 | 180 | 142 | 85.3 | 206 | |
Water level normal, m | 485 | 170–175(?) | - | 84.1 | 204 | |
Water level fluctuations, m | 3–4 | 7–10 | 9–10 | 3–4 | 3 | |
Water exchange ratio | 1:4.0 (1:3.1) | 1:2 | 4:1 | 1:3.7 | 1:5.2 | |
WATER PHYSICS | Temp. range, °C | 17–32 | 16–32 | 23–31 | 25–34 | 23.8–34.1 |
Thermal cycle | warm monomictic | warm monomictic | (± monomictic) | warm polymictic | warm dimictic | |
Temp. homothermy,°C | 20–22 (Jun.–Jul.) | 18.0 | 23–27.5 | 28.5 (Jan.–Mar.) (Jul.–Oct.) | ≤ 27 (Dec.–Feb.) (Jul.–Sep.) | |
Thermal strat. period | Oct.–June | May–Aug. | Feb.–mid May | Apr.–Jun. and Nov.–Dec. | Mar.–Jun. and Oct.–Nov. | |
Depth of mixed layer, m | 15 – 25 | 13 – 20 | 15 – 20 | 25 – 35 | 5 – 10 | |
Secchi D.V., cm | 50 –1060 (405) | 20 –400 | 10 –300 | 10 –450 | 10 –300 | |
Depth euphotic zone, m | 2 – 24 (10–16) | 1 – 10 | ab. 1–8 | ab. 10 | - | |
WATER CHEMISTRY | pH | 6.8– 8.9 | 7.1– 9.4 | 6.0– 8.0 | 6.8– 8.5 | 6.8– 9.0 |
Conductivity k20 μmhos | 50 – 115 (72) | 210 –250 | 40 – 54 | 50 – 80 | 36 –128 | |
Total solids, mg/L | 40 – 70 | 260 | (35 –40) | 60 – 80 | - | |
Diss. oxygen surf. mg/L | 6 – 10 | 2 – 7 | - | 5 – 8 | (1 – 10) | |
Oxygen stratification | Oct. –June | June–(Dec.) | Mar–mid May; Oct.–Nov. | Nov.–Jan. & Apr.–Jul. | Oct.–Nov. & Mar.–Jun. | |
FISHERY MANAGEMENT | Bush clearing, type | large areas totally cleared and dispersed around the lake, within the littoral zone | none | Foge Island and access strips | in front of the dam only | - Front of the dam |
- Strips 100 m-wide for navigation and for fishing (ab. 950 km) | ||||||
Total area, sq. km | 954 | - | 512 | - | 95 | |
Area, percent surf.area | 17.8 | - | 40 | - | 6 |
1 For additional data on morphometry, see Table 38.
2 Physical and chemical data for 1973, filling phase.
Table 4. Basic data on six tropical and sub-tropical African man-made lakes
(from Petr, 1975)
Lake | Size of the full lake (km-2) | Dam formed on the river (country) | Geographic or vegetation zone | Dam closed | Period of filling (years) | Maximum depth (m-1) | Maximum drawdown (m-1) | Ratio of annual outflow to volume |
Volta | 8482 | Volta (Ghana) | Savanna-woodland | May 1964 | 5 | 74 | 4 | 1:4 |
Kariba | 5364 | Zambezi (Zambia, Rhodesia) | Savanna-woodland | Dec. 1958 | 4½ | 93 | 8o | 1:9 |
Kainji | 1270 | Niger (Nigeria) | Savanna | Aug. 1968 | 3 months | 65 | 11 | 4:1 |
Nyumba ya Mungu | 148 | Pangani (Tanzania) | Savanna | Dec. 1965 | 2½ | 45 | - | - |
Ayame | 186 | Bia (Ivory Coast) | Rain forest | Aug. 1959 | - | 20 | - | - |
Nasser/Nubia | 3330 | Nile (Egypt) | Desert | 1964 | 10 | 97 | 10 | 1:2 |
o McLachlan, A.J. & McLachlan, S.M. (1971).
Lake surface areas given by Fels & Keller (1973) differ from those above which are taken from various papers and reports published by workers directly involved in research on these water bodies.
Table 5. The major man-made lakes in the tropical belt (Petr, 1978)
Lake | Size of the full lake (km2) | Dam formed on the river (country) | Geographic or vegetation zone | Dam closed | Period of filling (yrs) | Max. depth (m) | Max. draw-down (m) | Ratio of annual outflow to volume | |
Africa | |||||||||
Volta | 8482 | Volta (Ghana) | savanna-woodland | May 1964 | 5 | 75 | 4 | 1:4 | |
Kariba | 5250 | Zambezi (Zambia, Rhodesia) | savanna-woodland | Dec. 1958 | 4½ | 120 | 14 | 1:9 | |
Cabora Bassa | 2739 | Zambesi (Mozambique) | savanna | Dec. 1974 | 1 | 151 | 36 | - | |
Nasser/Nubia | 3330 | Nile (Egypt) | desert | May 1964 | >10 | 130 | 10 | 1:2 | |
Kainji | 1270 | Niger (Nigeria) | savanna | Aug. 1968 | 3 months | 50 | 11 | 4:1 | |
Kossou | 1600 | White Bandama (Ivory Coast) | forest-savanna | Feb. 1971 | 7(?) | 54 | 3 | 1:5 | |
South America | |||||||||
Brokopondo | 1560 | Surinam (Surinam) | forest | Feb. 1964 | 7 | 46 | 3 | 4:3 | |
Australia | |||||||||
Argyle | 3089 | Ord (Australia) | savanna | Nov. 1971 | <1o | 68oo | - | - |
o filled to tunnel intake level within the first wet season
oo dam height above original river level
Note: the data as presented in this table may differ from those of other authors. This table is based on the most recent information available.
Table 6. Fish species caught in the coffer-dammed lake and in the
River Niger as described by Daget (1962) and White (1965)
(from Motwani and Kanwai, 1970)
Fish species | Lake | River Niger | Lake (1978) | ||
(1966) | Daget (1962) | White (1965) | Personal data | ||
1. | Protopterus annectens (Owen) | - | X | X | X |
2. | Polypterus endlicheri endlicheri (Heckel) | X | - | X | X |
3. | P. senegalus senegalus (Cuvier) | - | X | X | X |
4. | P. bichir lapradei (Steindachner) | - | X | X | X |
5.x | Clupisudis (Heterotis) niloticus (Cuvier) | X | X | X | X |
6.* | Microthrissa miri Daget | X | X | X | X |
7.x | Hyperopisus bebe occidentalis (Günther) | X | - | - | X |
8. | Mormyrus hasselquisti Cuvier & Valenciennes | X | - | X | X |
9.x | M. rume Cuvier & Valenciennes | X | X | X | X |
10.x | M. macrophthalmus Günther | X | X | X | X |
11.x | Mormyrops deliciosus (Leach) | X | X | X | X |
12.x | M. oudoti Daget | X | - | - | X |
13. | M. engystoma Boulenger | X | - | - | - |
14. | Petrocephalus bane ansorgei (Boulenger) | X | - | - | - |
15. | P. bovei (Cuvier & Boulenger) | - | - | X | X |
16. | P. simus Sauvage | - | - | X | X |
17. | Marcusenius ihuysi (Steindachner) | - | X | - | X |
18. | M. isidori (Cuvier & Valenciennes) | X | - | X | X |
19.x | M. harringtoni Boulenger | X | X | - | X |
20.x | M. psittacus Boulenger | X | X | X | X |
21.x | Gnathonemus tamandua (Günther) | X | - | X | X |
22.x | G. abadii Boulenger | X | - | X | X |
23.x | G. pictus Marcusen | X | - | X | X |
24. | G. petersii Günther | X | - | - | X |
25.x | G. deboensis Daget | X | X | - | X |
26.x | G. niger (Günther) | X | - | X | X |
27.x | G. senegalensis Steindachner | X | - | X | X |
28. | G. cyprinoides Linnaeus | X | - | X | X |
29. | Popyrocranus (Notopterus) afer Günther | - | X | X | - |
30. | Xenomystus nigri (Günther) | X | - | X | - |
31.x | Gymnarchus niloticus Cuvier | X | X | X | X |
32. | Hepsetus odoe (Bloch) | - | X | X | X |
33.x | Hydrocynus lineatus Bleeker | X | X | X | X |
34.x | H. forskali Cuvier | X | X | X | X |
35. | H. brevis Günther | - | X | - | X |
36.x | Alestes dentex sethente (Cuvier & Valenciennes) | X | X | X | X |
37.x | A. baremose (Joannis) | X | X | X | X |
38.x | A. nurse Rüppell | X | X | X | X |
39. | A. leuciscus Günther | X | X | X | X |
40.x | A. macrolepidotus (Cuvier & Valenciennes) | X | X | X | X |
41. | A. imberi Peters | X | - | - | - |
42. | Micralestes acutidens (Peters) | - | X | - | X |
43. | Micralestes sp. | - | X | - | - |
44.x | Distichodus rostratus Günther | X | X | X | X |
45.x | D. engycephalus Günther | X | - | X | X |
46. | D. brevipinnis Günther | - | X | X | X |
47.x | Citharinus citharus (Geoffroy St. Hilaire) | X | X | X | X |
48.x | C. latus Müller & Troschel | X | X | X | X |
49.x | C. distichoides Pellegrin | X | X | X | X |
50. | Citharidium ansorgei Boulenger | - | - | X | - |
51.x | Labeo coubie Rüppell | X | X | X | X |
52. | L. pseudocoubie Blache & Milton | X | - | X | X |
53.x | Labeo senegalensis Cuvier & Valenciennes | X | X | X | X |
54. | L. parvus Boulenger | X | X | X | X |
55. | Barbus occidentalis Boulenger | - | X | - | X |
56. | B. ablabes (Bleeker) | - | X | - | X |
57. | B. atokorensis | - | X | - | - |
58. | B. macinensis Daget | - | X | - | - |
59. | B. leonensis Boulenger | - | X | - | - |
60. | B. senegalensis | - | X | - | - |
61. | Barbus sp. | - | X | - | - |
62. | Barilius senegalensis Steindachner | X | - | - | X |
63. | B. niloticus (Joannis) | - | X | - | X |
64. | Chelaethiops elongatus brevianalis Daget | X | - | X | - |
65. | Heterobranchus bidorsalis (Geoffroy St. Hilaire) | - | X | X | X |
66. | Clarias lazera Cuvier & Valenciennes | - | X | X | X |
67. | C. anguillaris (Linnaeus) | - | X | X | X |
68.x | Eutropius niloticus (Rüppell) | X | X | X | X |
69.x | Schilbe mystus (Linnaeus) | X | X | X | X |
70. | Siluranodon auritus Daget | - | - | X | X |
71. | Physailia pellucida Boulenger | X | - | X | X |
72. | Arias gigas Boulenger | X | - | X | X |
73.x | Bagrus bayad macropterus Pfaff | X | X | X | X |
74.x | B. docmac niger Daget | X | X | X | X |
75.x | Clarotes laticeps (Rüppell) | X | X | X | X |
76.x | C. macrocephalus Daget | X | - | - | X |
77.x | Chrysichthys auratus longifilis (Pfaff) | X | X | X | X |
78.x | C. furcatus Günther | X | X | - | X |
79.x | C. nigrodigitatus (Lacepede) | X | X | X | X |
80. | Auchenoglanis biscutatus (Geoffory St. Hilaire) | - | X | X | X |
81. | A. occidentalis (Cuvier & Valenciennes) | - | - | X | X |
82.x | Synodontis batensoda Rüppell | X | - | X | X |
83. | S. budgetti Boulenger | X | X | X | X |
84.x | S. courteti Pellegrin | X | X | X | X |
85.x | S. clarias (Linnaeus) | X | - | - | X |
86. | S. eupterus Boulenger | - | X | X | X |
87. | S. filamentosus Boulenger | X | X | X | X |
88.x | S. gambiensis (Günther) | X | X | X | X |
89.x | S. gobroni Daget | X | - | X | X |
90.x | S. membranaceus (Geoffroy St. Hilaire) | X | X | X | X |
91. | S. melanopterus Boulenger | X | X | X | X |
92. | S. nigrita Cuvier & Valenciennes | X | X | X | X |
93.x | S. omias Günther | X | - | - | X |
94. | S. ocellifer Boulenger | X | - | X | X |
95.x | S. resupinatus Boulenger | X | - | X | X |
96. | S. robbianus J.A. Smith | X | - | X | X |
97. | S. schall (Bloch & Schneider) | X | X | - | X |
98.x | S. sorex Günther | X | X | X | X |
99.x | S. violaceus Pellegrin | X | X | X | X |
100.x | S. vermiculatus Daget | X | - | X | X |
101.x | Malapterurus electricus (Gmelin) | X | - | X | X |
102.x | Lates niloticus (Linnaeus) | X | X | X | X |
103. | Hemichromis fasciatus Peters | X | X | X | X |
104. | H. bimaculatus Gill | X | X | X | X |
105. | Pelmatochromis güntheri (Sauvage) | X | X | - | X |
106. | Tilapia nilotica (Linnaeus) | X | X | X | X |
107. | T. galilaea Artedi | - | X | X | X |
108. | T. monodi Daget | X | X | X | - |
109. | T. melanopleura Dumeril | X | X | X | - |
110. | T. zillii Gervais | X | X | X | X |
111. | Ctenopoma petherici Günther | - | X | X | X |
112. | C. kingsleyae Günther | - | X | X | X |
113. | Epiplatys senegalensis (Steindachner) | - | X | - | - |
114. | E. bifasciatus taeniatus (Pfaff) | - | X | - | - |
115. | Aplocheilichthys gambiensis Svensson | - | X | X | X |
116. | Parophiocephalus obscurus (Günther) | - | X | X | X |
117. | Mastacembalus sp. | - | - | X | X |
118. | Tetraodon fahaka strigosus (Bennett) | X | - | X | X |
119. | Lutjanus agennes (?) | X | - | - | - |
Table 7. Fish observed in fishermen's catches between Bussa and Yelwa
on the River Niger.
I = Bussa,
II = Old Bussa,
III = Amboshidi,
IV = Shagunu,
V = Tungan-bori,
A = our data,
B = White (1965)
(from Motwani and Kanwai, 1970)
Species | Numbers examined | Station | Size Range (total length, in mm.) | |||||
I | II | III | IV | V | A (1966) | B (1965) | ||
Polypterus ansorgei | 16 | - | - | x | x | x | 300–560 | - |
P. bichir lapradei | 3 | - | - | x | x | - | 405–450 | 250–630 |
P. endlicheri endlicheri | 3 | - | x | x | - | - | 290–460 | 330–520 |
P. senegalus senegalus | 5 | - | - | x | x | - | 250–325 | - |
Clupisudis miloticus | 9 | x | - | x | x | x | 530–795 | - |
Hyperopisus bebe occidentalis | 16 | x | x | x | x | x | 285–445 | 210–490 |
Mormyrus rume | 16 | x | x | x | x | x | 230–700 | - |
M. macrophthalmus | 1 | x | - | - | - | - | 295 | 210–420 |
Mormyrops deliciosus | 20 | x | x | x | - | - | 150–730 | - |
M. oudoti | 1 | x | - | - | - | - | 500 | - |
Petrocephalus bane ansorgei | 2 | x | - | - | - | - | 100–140 | - |
Marcusenius psittacus | 1 | x | - | x | - | - | 175 | 130–190 |
Gnathonemus abadii | 1 | - | - | - | x | x | 250 | 140–290 |
G. pictus | 3 | - | - | x | x | - | 130–220 | 170–280 |
G. senegalensis | 5 | - | - | x | - | x | 230–290 | - |
G. tamandua | 9 | x | x | - | x | x | 325–370 | 230–410 |
Gymnarchus niloticus | 3 | x | - | x | - | x | 345–430 | - |
Hydrocynus lineatus | 2 | - | - | - | - | - | 620–630 | - |
Alestes baremose | 3 | x | - | - | - | x | 225–285 | 200–360 |
A. dentex | 4 | x | - | x | - | x | 130–220 | 150–330 |
A. macrolepidotus | 13 | x | x | - | - | - | 420–550 | - |
A. nurse | 6 | x | - | x | x | - | 105–190 | 110–250 |
Distichodus brevipinnis | 3 | - | - | - | - | x | - | - |
D. engycephalus | 14 | x | x | x | - | - | 320–750 | - |
D. rostratus | 41 | x | x | x | x | x | 160–825 | - |
Citharinus citharus | 12 | x | - | x | - | x | 255–380 | 140–400 |
C. latus | 1 | x | - | - | - | - | 495 | - |
Labeo coubie | 39 | x | x | x | - | x | 150–720 | - |
L. pseudocoubie | 6 | - | x | x | - | x | 185–500 | - |
L. senegalensis | 4 | x | - | - | - | x | 410–510 | 160–540 |
Heterobranchus longifilis | 1 | - | - | x | - | - | 310 | - |
Clarias anguillaris | 13 | - | - | x | x | x | 200–450 | - |
C. lazera | 4 | - | - | x | - | - | 230–390 | - |
Eutropius niloticus | 9 | x | - | x | - | - | 105–180 | - |
Schilbe mystus | 8 | x | - | x | - | - | 120–300 | - |
Bagrus bayad | 1 | - | - | x | - | - | 345 | - |
B. docmac | 1 | x | - | - | - | - | 490 | - |
Clarotes laticeps | 7 | x | - | x | x | - | 190–375 | - |
Chrysichthys longifilis | 1 | - | - | x | - | - | 210 | - |
Auchenoglanis biscutatus | 9 | - | - | x | x | x | 190–400 | - |
A. occidentalis | 5 | x | - | x | - | x | 240–480 | - |
Synodontis batensoda | 10 | - | - | x | x | - | 145–190 | - |
S. budgetti | 28 | x | - | - | - | x | 230–450 | 130–410 |
S. courteti | 28 | x | x | x | - | - | 335–680 | - |
S. clarius | 1 | x | - | - | - | - | 290 | - |
S. filamentosus | 1 | - | - | - | - | x | 105 | 160–280 |
S. gambiensis | 17 | x | x | x | x | x | 100–385 | 140–420 |
S. gobroni | 18 | x | x | x | - | - | 380–780 | - |
S. membranaceous | 3 | x | - | - | - | x | 290–370 | - |
S. nigrita | 35 | x | - | x | x | - | 80–170 | - |
S. ocellifer | 15 | - | - | x | x | - | 110–210 | - |
S. resupinatus | 3 | - | - | - | - | x | 165–265 | - |
S. sorex | 26 | x | x | x | - | x | 280–470 | 210–430 |
S. violaceous | 8 | x | - | x | - | x | 260–420 | - |
S. vermiculatus | 7 | x | x | - | - | - | 410–470 | - |
Malapterurus electricus | 1 | - | - | x | - | - | 390 | - |
Lates niloticus | 6 | - | - | x | x | x | 225–500 | - |
Tilapia nilotica | 9 | - | - | x | - | x | 140–330 | 110–420 |
T. zillii | 2 | - | - | x | - | - | 125–245 | 110–260 |
Tilapia spp. | 60 | x | - | x | - | x | 110–250 | - |
Parophiocephalus obscurus | 1 | - | - | x | - | - | 250 | - |
600 | 34 | 14 | 43 | 19 | 29 |