Freshwater entry behaviour of a non‐migratory stenohaline marine fish Takifugu snyderi

We conducted salinity choice trials with the stenohaline marine species Takifugu snyderi to test their freshwater (FW) entry frequency in relation to starvation. The fish preferred to enter non‐natal FW rather than remain in seawater. No relationship was detected between starvation and FW entry behaviour. Our results provide new empirical evidence of a stenohaline fish entering a non‐natal osmotic environment. Further research on the entry of stenohaline species such as this one into lethal environments may help determine if this might help promote the evolution of diadromous life histories.