Rescuing aquatic frogs and fish

Byron

The thought of an aquarist having to pass some sort of test before being allowed to own fish has an appeal...

Olympia

I always thought those clear tubes were fine for knives. Adult knives are pretty much blind and see using electricity, so supposedly sensing the clear tube is surrounding them is all they need. Maybe it's not working because they're babies and can still see? o.o So confusing.
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Byron

I am not certain of the African species, but assume it is similar to the the SA Black Ghost Knife that has eyes and is severely stressed out by light, being nocturnal, which is why it swims erratically in brightly-lit tanks and needs dark hiding spots.

Olympia

In this case I was talking about the SA species. Interesting how well the clear tube advertising convinced me.
The African knife appears to have decent vision throughout it's life, I haven't heard otherwise and adults still have quite large eyes.

eug

Ah, I didn't realize the difference in species - I don't know if the clearness of the hiding place is the problem in itself, but the knives aren't hiding in there so they clearly don't feel secure for whatever reason.

Byron

Knifefish require a very specific aquascape, as is laid out in the profile of the Black Ghost Knifefish [click shaded name].

The Vancouver Aquarium where I live has a display tank about 8 feet tall, and I don't know how deep, with a shoal of Pterophyllum scalare and a group of Black Ghost Knifefish. The light over the tank is very dim, barely sufficient to allow you to see inside the tank. After you stand in front of it for a few moments and yours eyes adjust, the sight is wonderful indeed. The shimmering "shadows" of the knifefish with that white lateral line moving around the dim tank, with the silver and black barred angelfish hovering around a sunked tree branch is mesmorizing.

Byron.

eug

My friend it turns out is basically subletting the place from somebody who he doesn't really know that well, and he doesn't feel comfortable with giving the fish away. Without my being able to convince him otherwise, I'm in a really frustrating situation...

Anyway, I visited the tanks, they were dirty and being unplanted and overfed, they were filthy and in desperate need of a water change. Did a large water change on the pleco tank, which has about a 42 gallon capacity, about a meter long. The other tank is tiny, not even 20 gallons, and clearly unsuitable for the knives. As an interim solution, we decided it best that we try to see if the plecos and the knives will be able to share the space in the larger tank - it will rather overstocked but at the very least the knives will have enough space to maneuver reasonably freely. I am going back there next week and help with the transition and carefully monitor the situation. If my friend is unwilling to give away the fish, I figure the next best thing would be to train him to do water changes and make sure the knives have adequate hiding places, and advise him on some floating plants he can introduce to the larger tank.

eug

I'll note that the knives are still juvenile, about 6 inches in length, so the meter-long tank might be okay as an interim solution. I realize it's too small for adult knives.