Diving beetles strip eel to the bone

Abstract

Wetting and drying cycles are widely recognised as driving aquatic macroinvertebrate and zooplankton production, providing prey and recruitment opportunities for fish in floodplain river systems. Conversely, invertebrate consumption of fishes features less frequently in food web studies. We used two sources of information: a) the finding of an intact eel skeleton and an exceedingly high number of diving beetles (Cybister sp.) from an overnight fyke net catch, and, b) catch records of large diving beetles according to wetland type in northern Queensland, Australia, to discuss the possible role of diving beetles in tropical wetlands. We contend that wetlands with wetting and drying cycles, and notably those with floating plants such as lilies completely covering the water surface, are likely to provide seasonal arenas for diving beetles to gain advantage over gill breathing vertebrates.