The influence of the salinity on the performance of the sibling species <i>Tisbe holothuriae</i> and <i>T. battagliai</i> in pure and mixed cultures was studied, using laboratory stocks adapted to 32 pro mille for over 175 generations. Cohort studies show that <i>T. holothuriae</i> has higher growth rates (R<sub>0</sub> and r) at 32 pro mille, <i>T. battagliai</i> 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, <i>T. holothuriae</i> eliminates its sibling species in less than 2 generations, apparently through chemical interference. With water... |