Salt in FW Aquaria
It is tough for me to come up with a subject line that is short and understandable for this post, so, I apologize if this veers off from what you may think it is.
Now I know that few of you read, or even look at scientific journals in pursuit of your fish hobby, but I at least skim the one I will be mentioning four times a year (what a coincidence that it is also published 4 times during the year), and do occasionally, as the opportunity presents itself, look at others that may have articles that I would consider relevant, even in an obtuse manner. The publication I am talking about today is _Copeia_, and, if not in your collection, may be found in most large university libraries, as well as others that may have a program for fish (ichthyology) and/or reptiles (herpetology). The reference would be:
Fuller, Rebecca C., “A Test for a Trade-Off in Salinity Tolerance in Early Life-History Stages in _Lucania goodei_ and _L. parva_”, _Copeia_ 2008, No. 1, 154-157.
The two fish listed here are North American fish, with _L. goodei_ found in mostly freshwater, and _L. parva_ found in mostly brackish water, and are closely related. What was done was to breed these fish, the former in water with various concentration of salt added to fresh water and the latter to increasingly fresh water to determine the viability of the eggs and fry. As the water got increasingly saltier, the _L. goodie_ egg and fry viability decreased, and the opposite was not true for the _L. parva_. _L. parva_ viability of eggs and fry remained virtually the same no matter the decrease in salinity of the water.
So, the sage aquarist may ask, what does this mean to me? Well, frankly, it may not mean much. However, if you are one who likes to use prophylactic doses of salt in your tanks, and may wish to breed fish, it may mean a lot when it comes to the number of eggs you get, and the number of fry that may be raised to maturity for fish normally found in fresh water.
Inferring does have its hazards. The study did not measure the viability of the adult fish in various salinities, so the above warning about using salt as a prophylactic is merely conjecture, but if you are one who always adds salt to a tank when doing water changes may want to think about abandoning the use of salt, especially when breeding, to avoid any adverse effects it may have.
Be aware that the temporary use of slat when treating for disease can be effective, especially when it is indicated that it should be used, i.e. in the treatment of ich. However, using salt as a continual prophylactic should be rethought.
Have at it people.
\Steve//
Category: AquaticLife
