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Niche segregation among Lake Malawi cichlid fishes? Evidence from stable isotope signatures
Author(s) -
Martin J. Genner,
George F. Turner,
Sam Barker,
S.J. Hawkins
Publication year - 1999
Publication title -
ecology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.852
H-Index - 265
eISSN - 1461-0248
pISSN - 1461-023X
DOI - 10.1046/j.1461-0248.1999.00068.x
Subject(s) - cichlid , sympatric speciation , niche , interspecific competition , ecology , littoral zone , biology , niche differentiation , subgenus , ecological niche , isotope analysis , sympatry , fish <actinopterygii> , habitat , fishery , taxonomy (biology)
The fish communities of the rocky littoral zone of Lake Malawi contain a large number of ecologically similar cichlid species. It has been suggested that dietary niche segregation may play a role in the coexistence of these species, but previous studies have yielded ambiguous results. Stable isotope analysis was used to determine whether five sympatric species are segregated by diet. Significant differences were found between the mean isotopic signatures of the study species, but there was considerable interspecific overlap between three species from the same subgenus that were anatomically almost indistinguishable. The implication that this was due to substantial dietary similarity was supported by stomach content analysis. We propose that ecological segregation may not always be necessary to allow coexistence of Lake Malawi cichlids.