Occurrence (present/absence) and abundance of zooplankton in Murchison Bay, Lake Victoria

Study Extent

Sampling was conducted in August/September 2012 and August 2013.

Sampling

Zooplankton samples were collected with a conical plankton net (Nansen type; mesh size 60 µm; mouth diameter 0.25 m), towed vertically through the water column, as described by Mwebaza-Ndawula (1994). Each sample was washed with tap water in the laboratory over a 53 µm sieve to remove the preservative and then diluted to a suitable volume, depending on the concentration of organisms in each sample. Sub-samples of 2, 2, 5 and 10 mL were taken with a wide bore automatic pipette from a well-agitated sample. The sub-sample series was performed to consider the more abundant organisms in 2, 2 mL series, and the rarer organisms in 2, 2, 5, 10 mL series. Each sub-sample was put into a counting chamber and examined under an inverted microscope (Hund, Wetzlar, Germany) at X100 magnification for taxonomic determination, and X40 for counting and organism body measurements.

Quality Control

Some zooplankton were able to be identified to species level using published taxonomic keys (Sars 1895; Pennak 1953; Brooks 1957; Rutner-Kolisko 1974; Koste 1978; Boxshall & Braide 1991; Korinek 1999). Taxonomic names were cross-checked using the World Register of Marine Species (WoRMS). Densities of organisms were calculated from the counts, with reference to the sample net mouth diameter and water column depth at each sampling site (Mwebaza-Ndawula L., 1998).

Method steps

1. Collection of the zooplankton In the field, a conical plankton net (Nansen type; mesh size 60 µm; mouth diameter 0.25 m), towed vertically through the water column to have an integrated sample was used to collect the zooplankton. Three hauls were taken per site and were combined to make a composite sample. Preserving the samples The composite sample was preserved with sugar-formalin, in a ratio of 1-part formalin to 10 parts sample volume, the sugar was to stop the ballooning of cladocerans for easy identification. Identification of zooplankton taxa In the laboratory, samples were washed using a sieve of 53 µm to remove the fixatives. Some organisms were identified to species level using published keys (Sars, 1895, Pennak, 1953, Brooks, 1957, Rutner-Kolisko, 1974, Koste, 1978, Boxshall and Braide, 1991, Korinek, 1999). The density of organisms was calculated from the counts data, with reference to the sample net mouth diameter and water column depth at each sampling site (Mwebaza-Ndawula, 1998, unpubl. PhD Thesis)

This dataset consists of freshwater zooplankton

1. Afrocyclops
   rank: genus
2. Ascomorpha
   rank: genus
3. Asplanchna
   rank: genus
4. Bosmina longirostris
   rank: species
5. Brachionus angularis
   rank: species
6. Brachionus bidentata
   rank: species
7. Brachionus budapestinensis
   rank: species
8. Brachionus calyciflorus
   rank: species
9. Brachionus caudatus
   rank: species
10. Brachionus dimidiatus
    rank: species
11. Brachionus falcatus
    rank: species
12. Brachionus forficula
    rank: species
13. Brachionus patulus
    rank: species
14. Brachionus plicatilis
    rank: species
15. Brachionus quadridentatus
    rank: species
16. Brachionus urceolaris
    rank: species
17. Brachionus variabilis
    rank: species
18. Calanoidae
    rank: family
19. Ceriodaphnia cornuta
    rank: species
20. Chydorus
    rank: genus
21. Cyclopoidae
    rank: family
22. Daphnia longispina
    rank: species
23. Daphnia longispina
    rank: species
24. Daphnia lumholtzi
    rank: species
25. Daphnia lumholtzi
    rank: species
26. Diaphanosoma excisum
27. Euclanis
28. Eucyclops
29. Filinia longiseta
    rank: species
30. Filinia opoliensis
    rank: species
31. Harpacticoida
    rank: order
32. Hexanauplia
    rank: class
33. Hexathra
    rank: genus
34. Keratella cochlearis
    rank: species
35. Keratella tropica
    rank: species
36. Lecane bulla
    rank: species
37. Lecane luna
    rank: species
38. Macrothrix
    rank: genus
39. Mesocyclops
    rank: genus
40. Moina micrura
    rank: species
41. Platyias
    rank: genus
42. Platyias quadricornis
    rank: species
43. Polyarthra
    rank: genus
44. Polyarthra vulgaris
    rank: species
45. Synchaeta
    rank: genus
46. Synchaeta pectinata
    rank: species
47. Thermocyclops decipiens
    rank: species
48. Thermocyclops emini
    rank: species
49. Thermocyclops incisus
    rank: species
50. Thermocyclops neglectus
    rank: species
51. Thermocyclops oblongatus
    rank: species
52. Thermodiaptomus galeboides
    rank: species
53. Trichocerca
    rank: genus
54. Trichocerca cylindrica
    rank: species
55. Tropocyclops confinnis
    rank: species
56. Tropocyclops tenellus
    rank: species
57. Tropodiaptomus stuhlmanni species
    rank: species

The dataset covers Murchison bay, Lake Victoria. The bay is adjacent to Kampala, the capital city of Uganda.