The crustacean zooplankton of Mali (West Africa). Faunal composition, community structure, and biogeography, with a note on the water chemistry of the lakes of the internal delta of the River Niger
Dumont, H.J.; Pensaert, J.; Van de Velde, I. (1981). The crustacean zooplankton of Mali (West Africa). Faunal composition, community structure, and biogeography, with a note on the water chemistry of the lakes of the internal delta of the River Niger. Hydrobiologia 80(2): 161-187. http://dx.doi.org/10.1007/BF00008434 In: Hydrobiologia. Springer: The Hague. ISSN 0018-8158; e-ISSN 1573-5117, more |  |
| Keywords | | | Author keywords | Cladocera Copepoda Africa Niger River biogeography community structure |
| Authors | | Top | - Dumont, H.J., more
- Pensaert, J.
- Van de Velde, I.
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| Abstract | 48 species of Phyllopoda, 24 species of Copepoda, and a freshwater shrimp are reported from Mali. Morphologically noteworthy or little known species are figured. Daphnia barbata and D. dolichocephala are redescribed. Three West-African species of Tropodiaptomus were found. T. senegambiae is synonymised with T. banforanus. Thermodiaptomus yabensis is fully figured. The distribution of T. yabensis and the regional Tropodiaptomus is discussed. A general biogeographical discussion is not yet possible, because for many species, and particularly Cladocera, both taxonomical position and chorological records are fragmentary and uncertain. At least 29 species, however, seem to be restricted to Africa, and some even to West Africa.The water chemistry of the lakes of central Mali is characterized by a low mineral content, but seems not to be distributive to any of the numerous zooplankton species encountered.The zooplankton communities, especially in the lakes of the internal delta of the Niger, are typically composed of numerous species. Among copepods, it is usual to find three or four genera to co-occur, and each genus may be represented by up to three species. This indicates long-term instability of the communities, and suggests strong interspecies competition to be present. This is corroborated by an analysis of the ranges of some African endemics.It is shown that the Niger delta is part of the biological boundary of the Sahara as far as aquatic invertebrates are concerned. West African equatorial climate endemics (e.g. 3 Tropodiaptomus species, Thermodiaptomus yabensis), and arid to semi-arid climate endemics (Daphnia barbata, D. longispina, Metadiaptomus mauretanicus) meet and interpenetrate each others' ranges over a short distance. |
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