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Differences in stable isotope composition within and among zooplanktivorous Utaka cichlid populations from Lake Malawi
Author(s) -
Anseeuw Dieter,
Guelinckx Jef,
Snoeks Jos
Publication year - 2010
Publication title -
african journal of ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.499
H-Index - 54
eISSN - 1365-2028
pISSN - 0141-6707
DOI - 10.1111/j.1365-2028.2009.01124.x
Subject(s) - intraspecific competition , ecology , sympatric speciation , range (aeronautics) , cichlid , biology , predation , composition (language) , geography , fish <actinopterygii> , fishery , linguistics , philosophy , materials science , composite material
Stable isotope analysis was used to determine whether five sympatric zooplanktivorous cichlids of the Utaka assemblage from Lake Malawi vary in isotopic signature as an indication of possible differences in food resource composition. The isotopic composition of the Utaka in combination with literature data about diet composition suggests that these species exploit a narrow range of zooplanktonic prey types. At five sampling locations, significant differences in δ 13 C and δ 15 N were detected among species but a consistent pattern across locations was absent. Significant intraspecific differences between locations were found. These differences were relatively low in view of the large geographic distances between the populations and there was no consistent spatial pattern among the species. The observed differences may be indicative of local variations in diet composition, which may help in reducing niche overlap among these zooplanktivores.