Composition and abundance of benthic macroinvertebrates in satellite lakes of Lake Victoria, Uganda

Study Extent

The datasets present data for surveys conducted between 1999 and 2003.

Sampling

A ponar grab with an open jaw area of 238 cm2 was used to take samples of benthic macroinvertebrates. One to three hauls were taken from each sampling point. When more than one haul was taken, they were mixed to form a composite sample. The bottom type at each point was described from the grabbed contents. This was captured as location remarks. Samples were concentrated and then placed in labeled sample bottles and preserved with 5% formalin solution. In the laboratory, each sample was rinsed with water and then placed on a white flat-bottomed tray. Macro-invertebrates were sorted, and individual taxa identified to the lowest possible taxonomic level using identification keys (Mandahl-Barth, 1954), Pennak, 1953), Merritt and Cummins, 1997, De Moor et al. 2003). All taxa were recorded, and individuals of each taxon enumerated to estimate their densities.

Quality Control

The samples were immediately processed in the field and treated with formalin to keep the organisms of interest intact. To avoid loss of organisms during sample processing, nets with appropriate mesh sizes were used.

Method steps

1. Collection of the macroinvertebrates In the field, sediment samples were collected using a ponar grab with an open jaw surface area of 238 cm2. At each site, three sediment samples were obtained. The three samples were mixed and concentrated to form one composite sample for each site. Preserving the samples The composite sample for each site was separately preserved in 5% formalin to maintain the organisms in good condition prior to analysis in the laboratory. Identification of macroinvertebrates In the laboratory, formalin was rinsed off from each sample and placed in white flat-bottomed trays. Using pairs of forceps, all benthic macro invertebrates were sorted from the sediment and the individual taxa identified to the lowest possible taxonomic level using appropriate identification keys and a dissecting binocular microscope at 4x 25 magnification.

Aquatic macroinvertebrates identified to phylum, class, subclass, order, family, subfamily, genus and species

1. Ablabesmyia Johannsen, 1905
   rank: genus
2. Baetidae
   rank: family
3. Bulinus (Müller O.F., 1781)
   rank: genus
4. Caenis Stephens, 1835
   rank: genus
5. Ceratopogonidae
   rank: family
6. Chaoborus A.A.H.Lichtenstein, 1800
   rank: genus
7. Chironomidae
   rank: family
8. Chironominae
   rank: subfamily
9. Chironomini
   rank: genus
10. Chironomus Meigen, 1803
    rank: genus
11. Clinotanypus Kieffer, 1913
    rank: genus
12. Clitellata
    rank: class
13. Coleoptera
    rank: order
14. Corbicula
    rank: genus
15. Corixidae
    rank: family
16. Ephemeroptera
    rank: order
17. Gomphidae
    rank: family
18. Hesperophylax (Banks, 1916)
    rank: genus
19. Hirudinea
    rank: subclass
20. Laevicaudata Linder, 1945
    rank: order
21. Libellulidae
    rank: family
22. Melanoides (Olivier, 1804)
    rank: genus
23. Nematoda
    rank: phylum
24. Neurocordulia (Selys, 1871)
    rank: genus
25. Ostracoda
    rank: class
26. Palpomyia Meigen, 1818
    rank: genus
27. Povilla adusta Navás, 1912
    rank: species
28. Procladius Skuse, 1889
    rank: genus
29. Tanypodinae
    rank: genus
30. Tanypus Meigen, 1803
    rank: genus
31. Trichoptera
    rank: order
32. Trombidiformes
    rank: order

The dataset covers satellite lakes of Lake Victoria, Uganda. The lakes are Kachera, Mburo, Nabugabo, Kayugi and Kayanja and Kijanebalora