Hexanematichthys seemanni

[feral]

i recently bought 2 Hexanematichthys seemanni or aluminium catfish as said the owner. Since i introduced them they have been displaying what i think is some form of agitation. They are swimming along the surface and periodically poking their heads completely out of the water. They have not fed or explored the rest of the tank. My aquarium is not salted only pure water heated to around 77 degrees. I am aware they prefer brackish conditions but was told they would be fine in pure water?

Help much appreciated-PAUL

[Richard B]

Aluminium cat is a totally different species to H.Seemanni. H seemani young will live in fresh water but salinity should increase as the fish grows/ages right up to full saltwater for adults.

What size are yours, How big is the tank, are there other fish, what is the pH, nitrate, nitrite, ammonia levels? Is there adequate oxygenation?

the more info you can provide the more accurate our advice. It sounds like considerable stress, but we need to ascertain what is causing it.

[feral]

Thanks for your prompt reply. Here is everything you thought might be usefull
My tank is approx 40 gallon and water levels are nitrate 0, ph 7.6, ammonia 0. I am running both a water and air pump and average temperature is around 78 degrees. I have 2 fish, 1 is approx 1inch and the other is half that. The other species in the tank are 6 clown loach around 1 inch, 6 white tip tetras, 3 male guppies, 6 black skirt tetra, and 6 minnow. I have a slate cave structure and around 10 plants so one side is heavily planted.

Many thanks-PAUL