Collected reprints: Abstract 3121
Collected reprints
Abstract
Bergmans, M.; Janssens, P.P.M. (1988). Competition between the sibling species Tisbe holothuriae and T. battagliai (Harpacticoida). Hydrobiologia 167/168: 455-462
The influence of the salinity on the performance of the sibling species Tisbe holothuriae and T. battagliai in pure and mixed cultures was studied, using laboratory stocks adapted to 32 pro mille for over 175 generations. Cohort studies show that T. holothuriae has higher growth rates (R0 and r) at 32 pro mille, T. battagliai at 20 pro mille. The latter's life cycle is much less affected by the difference in salinity. 'De Wit' replacement series were used to study competitive interactions. Without water renewal, T. holothuriae eliminates its sibling species in less than 2 generations, apparently through chemical interference. With water renewal, i.e. when exploitation competition becomes relatively more important, T. holothuriae still proves superior at 27 pro mille but the two species are competitively almost equal at 20 pro mille. The two species co-occur in situ during autumn, but their differential predominance at different sites is not explained by the effect of salinity.
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