Catfish With Red Mouthparts

[twintanks]

I switched my tank on this morning, to be greeted by my two smaller catfish, both of them sporting red outlines on their mouths. I am pushing things hard, I have to go out on "mercy errands" this afternoon, just managed to put the computer on now to post message. I have set up an 8 gallon temporary plastic tank plus a heater, so the water can warm up while I'm out, so that I can (hopefully) catch the critters and move them when I come back. I don't know what this is, they didn't have it yesterday. They are lively enough and feeding, but I have no idea what the red is, I'm assuming it is an inflammation of some kind, or bacterial infection. Can't get pictures at the moment (they're all hiding), but I guess someone will know what this is.
water parameters ammonia 0, nitrite 0, nitrate 5-10ppm.
One of the gouramis is rather quiet also, spending a lot of time up top looking at his face, but doesn't seem unwell otherwise.
I hope to get back home after 6pm this evening and start moving the fish if necessary....my hands are tied right now otherwise I'd move em now.

 

[fluttermoth]

What sort of 'catfish' are they?
 
What sort of substrate do you have?

 

[twintanks]

They are two trilineatus and one larger one yet to be identified. The substrate is small gravel, the same type as I have
in my goldfish/weather loach tank. I hear a lot about catfish should be on sand, if that is the case I wonder why the fish shops keep them in tanks with gravel? I checked this before purchase and was told that small rounded gravel shouldnt be an issue.

 

[jag51186]

Small rounded gravel really is fine, sand is just their natural preference because they sift it through their gills. My tank has both play sand and gravel in it, and my cories show no real preference either way.

The main concern is sharp gravel will end up making them lose their barbels.

Hope all yours are ok!

 

[twintanks]

Well so far they do all seem ok, they are in a spare plastic tank at present, for observation. After Friday's manic capers were over, I managed to sort them out; this morning only one of them has red marks (the smallest of the three). They're all eating and quite lively, so....well. I don't know. All the other fish seem well, bar a slightly constipated gourami. I did carry out a 60% water change, just to really freshen the main tank up (12 gallons out of 20) and do a bit of filter cleaning plus extra gravel vacuum. My only thought is whether the little one might have had a minor scuffle with a dwarf gourami, one of which has taken a real fancy to the new Vitalis catfish pellets.
I'll keep them under observation for another day or so.