Tail spine length in the Daphnia galeata complex: costs and benefits of induction by fish

摘要: We studied the combined effect of fish kairomones and food conditions on relative tail spine length (RTL) five Daphnia taxa, interaction these factors with vertical distribution daphnids. The experiment was done in two large-scale indoor containers, so-called plankton towers Plon, Germany. conducted a competition which level presence chemicals later were varied. A strong response RTL to (e.g., longer spines), significant differences between species, but no water depth found. Further, we observed that taxa produced higher only under high conditions. This suggests there is cost related production spines. In preliminary study lake Plussee, found had average than towers. noted sampling dates, may be lower level. also detected inverse correlation depth. discuss implications findings for co-existence co-occurring species their hybrids.