is a clown's rapid breathing linked to poor eating habits?

[tetraTim]

I picked up two Clown fish last Saturday.

One's clearly bigger and stronger from the get-go, and the other isn't.

The bigger one's doing great - fully coloured, eating everything I've put in (admittedly not a lot), and very active.

The smaller one, on the other hand, hasn't eaten since I got it, and it's noticeably skinnier. It's also lost the black markings that outline the white.

It's breathing heavily and just stays near the bottom, not venturing to the top.

I've checked the water stats - ammonia, pH, nitrate, and nitrite are all fine. The temperature's good too. I even moved the powerhead to get some surface movement, but no change.

My tank's new, and I'm probably guilty of rushing things, but one fish is spot on, while this one's been off since day one - it's just more noticeable now.

Any advice would be appreciated.

[felinxo]

This is a tough one, the other fish might not take kindly to being alone again if you remove the sick one. I'm thinking internal parasites could be the culprit here, no signs of anything external. If I were you, I'd move it to a separate container and try a treatment, but to be honest, I'm not optimistic.

If the worst happens and you lose the little guy, get the smallest, healthiest clown you can find and introduce it with the lights off.

[tetraTim]

Yeah, I'm thinking internal parasite too, probably the reason he's struggling. The LFS said they were new stock so I'm guessing that's where it came from, shame really, hate seeing a fish like that suffer.

[felinxo]

Top tip, Simon: when buying fish, consider this approach - select the ones you want, then tell the LFS you'll collect them in two weeks. It's tough to wait, I know, but often any issues will show up in their tank, not yours, giving you a better chance of getting a healthy fish.