Green Wolf Eel Experiment: Continued...

[Dave Legacy]

I just thought some of you guys might be interested in my experiment. About 2 months ago I bought a male Green Wolf Eel (Congrogadus subducens) to go in my 37G Tall High-Range Brackish tank. He came from the store in 1.019SG and I acclimated him into my tank at 1.017SG. Over the last two months I brought him down to 1.015SG and I noticed yesterday that his coloration has shifted to a much lighter color and he seems to be a little more reclusive than he usually is. I think this is a good sign that the salinity has gotten too low for him so I brought it back up to 1.017SG and will now continue to raise it until it gets to above 1.020SG to see if he reacts better.

Internet research told me that this pseudochromis is often found in brackish areas so I wanted to see how far I could take it. I chickened out for the good of my buddy. Although his feeding habits were as veracious as ever... maybe he was fine.

- Dave

 

[AMS]

I just thought some of you guys might be interested in my experiment. About 2 months ago I bought a male Green Wolf Eel (Congrogadus subducens) to go in my 37G Tall High-Range Brackish tank. He came from the store in 1.019SG and I acclimated him into my tank at 1.017SG. Over the last two months I brought him down to 1.015SG and I noticed yesterday that his coloration has shifted to a much lighter color and he seems to be a little more reclusive than he usually is. I think this is a good sign that the salinity has gotten too low for him so I brought it back up to 1.017SG and will now continue to raise it until it gets to above 1.020SG to see if he reacts better.

Internet research told me that this pseudochromis is often found in brackish areas so I wanted to see how far I could take it. I chickened out for the good of my buddy. Although his feeding habits were as veracious as ever... maybe he was fine.

- Dave

Interesting Dave. I would imagine he could go a little lower than 1.015. Congrogadus subducens is famous for changing color, as are some of the other pseudochromids to a lesser degree. Acting more reclusive and color changes (in the particular fish anyways) probably have nothing to do with salinity. If there were any syptoms out of the usual such as eating habits or any physical abnormalities then I would be concerned. It's probably worth experimenting with a lower specific gravity, as he it will probably be fine.

Good Luck Dave.


PS- Any more pictures?

 

[nmonks]

I'm with AMS on this; I'd see how things work out before panicking. For one thing, SG 1.018 is good enough for even marine fish that don't go into brackish water. (For many years, keeping marine fish at this relatively low salinity was advocated, but it doesn't work with invertebrates, and so has largely fallen out of use.)

My guess would be the limit would be nearer SG 1.010-1.012. That's sort of the balance point between water going in (as with fish in freshwater) and water being drawn out (as with fish in the sea). Thus, 1.015 should be safe as houses. Colour varies, but appetite and respiration rate are usually better indicators of the health of a fish.

Cheers,

Neale