Diversity and distribution of freshwater invertebrates in the Lake Victoria Basin

Study Extent

The macroinvertebrates were observed from Simiyu River catchment northern, Tanzania.

Sampling

Macroinvertebrates taxa presented in this dataset were collected from 11 sites spread across the Simiyu River catchment between 1 December 2019 and 31 December 2019. The macroinvertebrates were sampled in a semi-quantitative way using a kick net of 1mm mesh size on a 30-cm square frame following the TARISS sampling protocol (Kaaya et al., 2015). Samples were collected from the dominant habitat type present at each site (i.e., the habitat that covers about 70% of the 50 m stretch making up the river section at the site). Sampled habitat types included (i) stones in-current (cobbles, boulders and bedrock), (ii) vegetation/macrophyte, and (iii) gravel/sand/mud (GSM). All individuals in a sample were counted and identified to the family level following different identification keys (Croft, 1986; Davies and Day, 1998; Gerber and Gabriel, 2002).

Method steps

1. We collated all the macroinvertebrates data into Microsoft Excel spreadsheets according to Darwin-Core standard i.e., following Darwin core quick reference guide. We verified the taxonomic nomenclature using the “species matching” tool available under GBIF website (https://www.gbif.org/tools/species-lookup). To ensure data adherence to Darwin Core standards we performed data cleaning. We used data validator tool available under GBIF website (https://www.gbif.org/tools/data-validator) to identify missing or incorrect information in our dataset. The two tools used are open-source software.

This dataset present macroinvertebrate assemblages observed in Simiyu River catchment between 1 December 2019 and 31, December 2019. The dataset contains a total of 70 occurrences belonging to eight (8) orders and twenty-seven (27) families of riverine macroinvertebrates. The order Hemiptera had a higher number of family representation (6 families) followed by Ephemeroptera, Coleoptera and Gastropoda (4 families each), Odonata (3 families) and Diptera, Annelida and Gastropoda (2 families each).

1. Aeshnidae
   common name: Dragonflies rank: family
2. Atyidae
   rank: family
3. Baetidae
   common name: Small minnow mayflies rank: family
4. Belostomatidae
   common name: Giant water bugs rank: family
5. Caenidae
   common name: Small squaregilled Mayflies rank: family
6. Ceratopogonidae
   common name: No-see-ums rank: family
7. Chironomidae
   common name: Nonbiting midges rank: family
8. Coenagrionidae
   common name: Damselflies rank: family
9. Corixidae
   common name: Water boatman rank: family
10. Culicidae
    common name: Biting flies rank: family
11. Dytiscidae
    common name: Predacious diving beetles rank: family
12. Ephemeridae
    common name: Mayflies rank: family
13. Gerridae
    common name: Water striders rank: family
14. Haliplidae
    common name: Crawling water beetle rank: family
15. Heptageniidae
    common name: Stream mayflies rank: family
16. Hirudinidae
    common name: Leeches rank: family
17. Hydrophilidae
    common name: Water scavenger beetles rank: family
18. Leptophlebiidae
    common name: Prong-gilled mayflies rank: family
19. Libellulidae
    common name: Skimmers rank: family
20. Limnichidae
    common name: Minute marsh-loving beetle rank: family
21. Naucoridae
    common name: Creeping water bugs rank: family
22. Nepidae
    common name: Water scorpions rank: family
23. Notonectidae
    common name: Backswimmers rank: family
24. Oligochaeta
    common name: Earthworms rank: family
25. Planorbidae
    common name: Ramshom snails rank: family
26. Thiaridae
    common name: Trumpet snails rank: family
27. Veliidae
    common name: Small water striders rank: family

Simiyu River catchment is located in northern-Tanzania between longitude 33.46oE-34.84oE and latitude 2.36oS-3.27oS at 2.55⁰S. The catchment covers an area of 10,659 km2 and is located in two regions of Simiyu and Arusha. The river stretches about before it pours its waters into Lake Victoria; which forms part of the upper headwaters of the Nile River. Before it enters the lake, its main tributaries, Ngasamo and Bariadi Rivers join to form the Duma River, which later joins the main Simiyu River