The effects of two food sources on life history traits of Daphnia galeata, Daphnia cucullata and their interspecific hybrid, D.cucullataxgaleata, were studied. For each taxon, two clones were reared on both a green alga (Scenedesmus obliquus) and a filamentous cyanobacterium (Oscillatoria limnetica). Reproduction on Oscillatoria was generally lower than on Scenedesmus, but a positive population growth rate was still achieved, except in one hybrid clone. Life history traits showed differences among the intraspecific clones. Daphnia cucullata, the smallest of the three taxa, was the best of the three in utilizing Oscillatoria as food, but D.galeata and the hybrid did not differ clearly. The clones within the taxa also differed in the extent they could utilize Oscillatoria as food. The results are discussed in relation to the co-existence of these taxa in nature. [KEYWORDS: Interspecific hybridization; fresh-water; cladocerans; zooplankton; galeata; growth; lake; phytoplankton; assimilation; reproduction]
Original languageEnglish
JournalJournal of Plankton Research
Journal publication date1996

ID: 98289