Occurrence and diversity of aquatic macroinvertebrates in the Lake Manyara Basin, northern-Tanzania.

Study Extent

The macroinvertebrates were observed from 4 rivers, 1 permanent canal and 60 temporary wetlands systems of the Lake Manyara Basin, northern Tanzania

Sampling

Macroinvertebrates sampling was carried out three weeks after inundation of the wetlands during the wet seasons. Macroinvertebrates were collected in 60 temporary wetlands by sweeping a 250-µm mesh D-frame net in different pond habitats (i.e., vegetation and open water) with a distance of 1 m per sweep. The number of sweeps was proportionally distributed over all microhabitats with attention for pond margins and areas with submerged, floating, and emergent vegetation. Collected macroinvertebrates were preserved in 70% ethanol. In the laboratory, specimens were isolated and identified under a stereo microscope at 40X magnification. Macroinvertebrates were identified to genus level and where possible to species level following different identification keys.

Quality Control

Following Darwin's core quick reference, we compiled all the macroinvertebrate data into Microsoft Excel spreadsheets in accordance with the Darwin-Core standard. Using the "species matching" tool on the GBIF website (https://www.gbif.org/tools/species-lookup), we checked the taxonomic nomenclature. We cleaned the data to make sure it adhered to Darwin Core standard. To find any missing data in our dataset, we used the data validator tool on the GBIF website (https://www.gbif.org/tools/data-validator). Open-source software is used to create the two tools.

Method steps

1. Macroinvertebrate sampling was carried out three weeks after the inundation of the wetlands during the wet seasons. Macroinvertebrates were collected in 60 temporary wetlands by sweeping a 250-µm mesh D-frame net in different pond habitats (i.e., vegetation and open water) with a distance of 1 m per sweep. The number of sweeps was proportionally distributed over all microhabitats with attention to pond margins and areas with submerged, floating, and emergent vegetation. Collected macroinvertebrates were preserved in 70% ethanol. In the laboratory, specimens were isolated and identified under a stereo microscope at 40X magnification. Macroinvertebrates were identified at the genus level and where possible at the species level following different identification keys.

This dataset present macroinvertebrate assemblages observed in 4 rivers and 60 temporary wetlands and 1 permanent canal in the Lake Manyara Basin between May 2019 and December 2021. The dataset contains a total of 864 occurrences belonging to 33 genera. The main taxonomic groups in this dataset are species, genus, family, order and phylum.

1. Aedes aegypti
   common name: Yellow fever mosquito rank: species
2. Anisops sardea
   common name: Backswimmmers rank: species
3. Anopheles gambiae
   common name: African malaria mosquito rank: species
4. Chironomus riparius
   common name: Harlequin fly rank: species
5. Culex duttoni
   rank: species
6. Culex pipiens
   common name: Common house mosquito rank: species
7. Culex quinquefasciatus
   common name: Southern house mosquito rank: species
8. Eristalis tenax
   common name: Drone fly rank: species
9. Laccotrephes fabricii
   common name: Water scorpions rank: species
10. Lutzia tigripes
    rank: species
11. Pantala flavescens
    common name: Wandering glider rank: species
12. Ranatra fabricii
    common name: Water scorpions rank: species
13. Streptocephalus bourquinii
    common name: Fairy shrimp rank: species
14. Streptocephalus lamellifer
    common name: Fairy shrimp rank: species
15. Triops granarius
    common name: Predatory tadpole shrimp rank: species
16. Psychoda
    rank: genus
17. Lumbricus
    rank: genus
18. Megaselia
    rank: genus
19. Dasyhelea
    rank: genus
20. Gordius
    rank: genus
21. Lynceus
    rank: genus
22. Cyzicus
    common name: Clam shrimp rank: genus
23. Cyclestheria
    rank: genus
24. Dytiscus
    common name: Predaceous diving beetle rank: genus
25. Berosus
    rank: genus
26. Melanoides
    common name: Snails rank: genus
27. Lymnaea
    common name: Pond snails rank: genus
28. Pseudagrion
    common name: Damselflies rank: genus
29. Baetis
    common name: Mayflies rank: genus
30. Elophila
    common name: Moths rank: genus
31. Belostoma
    common name: Giant water bugs rank: genus
32. Calanoides
    rank: genus
33. Simocephalus
    rank: genus
34. Bosmina
    common name: Water fleas rank: genus
35. Phoan
    rank: genus
36. Leptestheria
    common name: Clam shrimps rank: genus
37. Tabanidae
    rank: family
38. Cytheridae
    rank: family
39. Aeshnidae
    common name: Dragonflies rank: family
40. Nepidae
    common name: Water scorpions rank: family
41. Belostomatidae
    common name: Giant water bugs rank: family
42. Atyidae
    rank: family
43. Leprophlebiidae
    common name: Prong-gilled mayflies rank: family
44. Sphaeriidae
    common name: Pea clams rank: family
45. Corixidae
    common name: Water boatman rank: family
46. Cyclopoida
    rank: order
47. Rotifera
    common name: Whirling animals rank: phylum

The Lake Manyara Basin extends from 3°5′ to 4°5′ S and from 35°51′ to 36°37′ East. It is located within the Babati and Mbulu districts in the Manyara region and Monduli and Karatu districts in the Arusha region; covering an area of about 6942 km2. The main source of water in the basin is through precipitation and run-off from the upper catchment. Eight rivers drain water into the Lake Manyara Basin, these include Mto wa Mbu, Simba, Kirurumo, Msasa, Endabashi, Lyambi, Magara, and Makuyuni: which are also used by the surrounding communities for irrigation farming and as a water source for cattles. The basin houses two lakes, Burunge, and Manyara, and ubiquitous temporary ponds which are a source of water for humans, domestic animals and wildlife. The basin is also a corridor for wildlife constantly moving to and from Tarangire, Burunge and Lake Manyara national parks (Ngana et al., 2004).