Non-destructive sampling of poison frogs for toxin analysis in forensic casework

Abstract

Poison frogs is the common name for several genera of frogs which occur naturally in Central- and South-America, Australia and Madagascar and which contain a wide variety of toxins. Their colourful appearance and minute size resulted in their extraction from their natural habitat for illegal trade, threatening population sizes. In order to fight this illegal trade, the poison frog’s ability to excrete environmentally acquired toxins via their skin can be used in criminal investigations. Since the frogs are not able to produce the toxins de novo, these alkaloid toxins have ultimately originated from their environment and are excreted through the skin, especially when stressed. Due to the reliance on a toxin-containing food source, we show that the presence of toxins in poison frogs can be used to distinguish between captive breeding and wild-capture in actual forensic case work. We describe the application of a gas chromatography-mass-spectrometry (GC-MS) analysis on non-destructively derived samples from living frogs in five seizures, the biological interpretation of presence and absence of toxins and the criminalistic interpretation of the findings given propositions of both the prosecutor and the defendant.