FW to SW and Back Again?
- Thread starter Oddball
- Start date
There are a whole host of cyprinodontiform fishes (killies and livebearers) like this, including Adinia xenica, Anableps sp., Cyprinodon variegatus, Fundulus grandis, F. grandissimus, F. heteroclitus, F. luciae, F. majalis, F. similis, Gambusia rhizophora, Krytolebias marmoratus, Poecilia latipinnis, P. velifer, etc., as well as certain atherinopsid silversides such as Menidia sp.
Technically, these small fishes are generally not amphidromous, as they aren't going anywhere, but rather adapting to the changing water around them. They occupy estuaries, lagoons, and other tidal-influenced areas that change salinity rapidly and often depending on the stage of the tide and the amount and circulation of freshwater discharge entering the system. The term used for plants in these habitats is "polyhaline", but I haven't seen that applied to fishes. The term "euryhaline" covers both these estuarine fishes and the properly amphidromous species, which move in and out of freshwater. The implications for aquarists are the same either way; these fish can usually adapt to a wide variety of water conditions, from hard freshwater to full seawater, and, in some cases, even hypersaline conditions too salty for most marine fishes.
Technically, these small fishes are generally not amphidromous, as they aren't going anywhere, but rather adapting to the changing water around them. They occupy estuaries, lagoons, and other tidal-influenced areas that change salinity rapidly and often depending on the stage of the tide and the amount and circulation of freshwater discharge entering the system. The term used for plants in these habitats is "polyhaline", but I haven't seen that applied to fishes. The term "euryhaline" covers both these estuarine fishes and the properly amphidromous species, which move in and out of freshwater. The implications for aquarists are the same either way; these fish can usually adapt to a wide variety of water conditions, from hard freshwater to full seawater, and, in some cases, even hypersaline conditions too salty for most marine fishes.
