, Volume 317, Issue 3, pp 177–182 | Cite as

Caridina nilotica in Lake Victoria: abundance, biomass, and diel vertical migration

  • John T. Lehman
  • Godfrey B. Mbahinzireki
  • Lucas Mwebaza-Ndawula


Caridina nilotica (Decapoda: Atyidae) in offshore waters of Lake Victoria were investigated with both day and night sampling over a period of two years. Offshore populations are mainly planktonic rather than benthic, and the animals exhibit diel vertical migrations into near-surface waters at night. These changes in diel abundance as well as the size-frequency distribution of the migrating shrimp suggest that the migratory behavior is in response to visual planktivory, because only the very smallest individuals (2–4 mm) remain in surface waters during the day. During October 1992, abundances were estimated both by vertical net sampling and by underwater video transect methods. Concordance was established between abundances estimated by the two methods. Only about 9% (night) to 14% (day) of the Caridina population appeared to be epibenthic. We suggest that the behavior of the animal is consistent with the hypothesis that it is not a strict detritivore as previously reported; rather it may engage in facultative planktivory, especially at night.

Key words

zooplankton biomass Lake Victoria diel vertical migration Caridina Chaoborus 


  1. Beadle, L. C., 1981. The inland waters of tropical Africa. Longman Group Ltd. pp. 475.Google Scholar
  2. Branstrator, D. K., L. M. Ndawula & J. T. Lehman. Zooplankton dynamics in Lake Victoria. In T. C. Johnson & E. Odata (eds), Limnology, Climatology and Paleolimnology of the East African Lakes. in press.Google Scholar
  3. Fryer, G., 1960. The feeding mechanism of some atyid prawns of the genus Caridina. Trans. r. Soc. Edin. 64: 217–244.Google Scholar
  4. Hughes, N. F., 1992. Nile perch, Lates niloticus, predation on the freshwater prawn, Caridina nilotica, in the Nyanza Gulf, Lake Victoria, East Africa. Envir. Biol. Fishes 33: 307–309.Google Scholar
  5. Lee, D. S. & D. J. Hall, 1989. Quantitative sampling of organisms/ macroparticulates with a ROV using a cillimated illumination system, p. 827–831. In Proc. Oceans'89 Tech. Soc., 1719 pp.Google Scholar
  6. Lehman, J. T. & D. K. Branstrator, 1993. Effects of nutrients and grazing on the phytoplankton of Lake Victoria. Verh. int. Ver. Limnol. 25: 850–855.Google Scholar
  7. Macdonald, W. W., 1956. Observations on the biology of chaoborids and chironomids in Lake Victoria and on the feeding habits of the ‘Elephant-Snout Fish’ (Mormyrus kannume Forsk). J. anim. Ecol. 25: 36–53.Google Scholar
  8. Mugidde, R., 1993. The increase in phytoplankton primary productivity and biomass in Lake Victoria (Uganda). Verh. int. Ver. Limnol. 25; 846–849.Google Scholar
  9. Nero, R. W., 1982. A description of three nets suitable for estimating the abundance of Mysis relicta. Can. Tech. Rep. aquat. Sci. 1046: iv+8 pp.Google Scholar
  10. Ogutu-Ohwayo, R., 1990. Changes in the prey ingested and the variations in the Nile perch and other fish stocks of Lake Kyoga and the northern waters of Lake Victoria (Uganda). J. Fish Biol. 37: 55–63.Google Scholar
  11. Worthington, E. B., 1931. Vertical movements of freshwater zooplankton. Int. Revue ges. Hydrobiol. Hydrogr. 25: 394–436.Google Scholar

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • John T. Lehman
    • 1
  • Godfrey B. Mbahinzireki
    • 2
  • Lucas Mwebaza-Ndawula
    • 2
  1. 1.Department of Biology and Center for Great Lakes and Aquatic Science, Natural Science BuildingUniversity of MichiganAnn ArborUSA
  2. 2.Uganda Fisheries Research InstituteJinjaUganda

Personalised recommendations