Does one result trump all others? A response to Magurran, Irving and Henderson

Magurran, Irving and Henderson have reported that a population of European minnows, Phoxinus phoxinus, did not show an obvious behavioural fright reaction when they were presented with conspecific skin extract in a wild situation. Fish from the same population show a strong response when tested in aquaria. From these data the authors conclude that the fright reaction may be contingent on such factors as assessed risk and hunger. From this reasonable hypothesis they progress to the assertion that the Schreckstoff of ostariophysan fishes should not be considered an alarm pheromone. Much of their paper is devoted to arguments supporting their hypothesis that Schreckstoff cannot operate as an alarm pheromone. I argue that it is appropriate and adaptive to respond to alarm signals in a contingent manner, and attempt to answer the various arguments regarding the validity of terming Schreckstoff an alarm pheromone.