Trimethylamine does not trigger antipredatory life history shifts in Daphnia

Abstract

I studied the responses of Daphnia galeata and Daphnia hyalina x galeata life history traits to trimethylamine (TMA) and fish kairomone. TMA and fish exudate had opposite effects on age at maturity and fecundity in two different experiments. The effects on size at maturity and offspring size were similar. Specific antipredatory life history shifts occurred only in response to fish exudate, whereas TMA caused changes that could be expected from any mildly harmful substance.