Testing whether carp can be located using Judas fish: a new behavioral tool to locate aggregating invasive fish so they might be tracked and/or removed
This project developed techniques to locate aggregating carp using sterile, sexually active Judas fish to determine if sterilized carp can be rendered sexually active with hormone implants. New sensory tools (e.g. sound playback) will be developed as needed to control the behavior and distribution of adults.
To remove highly mobile and invasive fish such as carp, we must know where they are. The Judas fish technique (tracking a few individual animals to find other members of their group) was developed as a means to locate low numbers of Asian carp in Minnesota waters. This technique has been used with great success in other locations. The first step was developing means to sterilize carp in collaboration with a veterinarian. Later, researchers developed means to track them using radio-transmitters in rivers. Common carp were our primary model but we included work on Asian carp in the laboratory. After initial research, it was determined that this technique would not work well with males competing in the wild. Research is now focused on conducting experiments to determine how to fully feminize sterile fish instead.