Genetic variation in anesthesia success in a New Zealand freshwater snail

Anesthesia is used to immobilize organisms for experiments and surgical procedures and to humanely mitigate pain. Despite its scientific importance, and though invertebrates seem to experience pain, overarching regulations for the application of anesthesia in invertebrate taxa do not exist. Indeed, the almost complete absence of legal requirements for invertebrate anesthesia might explain at least in part why there seems to have been little effort towards developing widely effective invertebrate anesthesia techniques. Here, we demonstrate that genetic differences between snails are a major driver of wide variation in menthol anesthesia success in an important freshwater snail model system, Potamopyrgus antipodarum. This is the first example of which we are aware of a role for genetic variation in anesthesia success in a mollusk. These findings both illuminate a potential mechanism underlying previously documented challenges in molluscan anesthesia and will set the stage for powerful and humane manipulative experiments in P. antipodarum.