1.Inanga (Galaxias maculatus) is a widespread Southern hemisphere fish known for its salinity tolerance (from near 0 to up to 48), a phenomenon even present during the first hours after hatching.
2.Inanga utilise rapid molecular, cellular and tissue physiological changes to ensure homeostasis following acute salinity challenge. However, to date no study has attempted to elucidate the physiological mechanisms that allow inanga to inhabit different salinities in the long term.
3.Inanga are one of only a few fish species that can be categorised as amphidromous.
4.Adults lay eggs in brackish, estuarine conditions, and after hatching larvae migrate to the ocean for a short period of feeding and growth, before returning to FW, where they primarily occupy habitats near the salt water wedge. This behaviour exposes the animals to daily and life history fluctuations in salinity.
5.Globally, less than 80 of the estimated 20 000 described fish species are known to exhibit amphidromy, and the physiology of amphidromous species is not well understood, despite their obvious value for studying salinity–organism interactions.