brackish water snowflake eel

Question
i have a 55 gallon brackish water aquarium, specific gravity of 1.005 (last i checked that was a few days ago but it should be a tad higher now, maybe 1.006), and an aquaclear filter listed for a 70 gallon aquarium. alot of algea has accumulated in my tank in the past 2 days because i have a new lighting system and have not had a chance to get a diatom filter (but green algea isn't bad for the fish, just looks bad... right?). i have a snowflake eel (Gymnothorax polyuranodon) that i've had for a few months and hes been doing great till now, i came home and he was swimming around at the top of the tank which is very strange, and it looked like he was gasping for air (almost as if hes swallowed a rock, but i don't think he has). also, i put him in the tank when it was still freshwater and have been very slowly putting salt in. so could this be a reaction to the salt even though hes a brackish fish? is he sick? help me! i really like this eel and don't want him to die!

Answer
Hi Lyle,
 That is a tough question for me because I have never kept a snowflake eel and don't know much about them.  However, I can tell you this: eels change their salinity preferences as they mature.  Certain eels start out in marine waters, then move into freshwaters to grow, then migrate back to the ocean to spawn. We call these fish "catadromous" and it is the opposite of anadromous fish like Pacific salmon, which start in freshwater, migrate to the ocean to grow, and then migrate back to freshwater to spawn.   (There are other eels, e.g., moray eels which stay in the ocean full time). There are no true eels which exist for their whole life in freshwater as far as I know.  The bottom line is that while many people say the snowflake eel is "brackish" that isn't really correct, in that they are only "brackish" for part of their life.  You will need to find out more details elsewhere about exactly when the transition period is for that particular species.  I hope this at least helps you understand the situation a bit.  Sorry I couldn't provide more details.

-- Ron
  rcoleman@cichlidresearch.com
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