“…a compound called schreckstoff. Many fish species excrete schreckstoff when they are injured. This alerts the rest of the school that danger is near. In a sense, fishes can actually smell fear. Schreckstoff was first documented in 1938 by Austrian ethologist Dr. Karl von Frisch [pictured here]. Because he didn’t know the chemical makeup of the compound, he simply called it schreckstoff—German for ‘scary stuff’.”
A compound called schreckstoff (“Scary Stuff”)
Schulterstück nach rechts gewandt, den Kopf im Halbprofil, Blick nach vorn zum Betrachter, mit kurzen Haaren, Brille, Hemd, Krawatte, Jackett, vor neutralem Hintergrund. Oben rechts eingeprägt Name ... - Quelle: http://www.deutsches-museum.de/archiv/