Loaches Online Forum

Hi.
I am a fish keeping beginner (6 months). I did my homework and know how large clowns can be. I currently have 6 in a 4ft 55 gallon tank. Next year I am re-housing the group into a larger 6ft tank. They are fed a variety of flake and frozen food. I also give them live food twice a week and a small amount of garden peas once a week. They share the tank with a red tailed black shark of the same size. There is no fighting or falling out - the only disagreements are when two of the loaches turn grey and start pushing each other.
My problem is that in the 6 months I have had them (they started at around 1" / 25mm not including the tail) 5 have doubled in size and really bulked out.
The sixth has not grown at all. He / she or peewee as we call him is the same size as when we purchased him. He is not bullied, plays with the group and exhibits exactly the same behaviour.
Have any members experienced this themselves ?....its almost as if his body is lacking the ability to digest nutrients. The worst thing is his eyes have grown (they look like spotlights) but his body hasn`t.
What happens next ?, should I expect him to have a short life as he is the "runt" of the litter , or is there anything I can do to help him ?
Your help would be much appreciated.

sounds like peewee has "skinny dz".
I am by no means an expert, but have been reading a lot, and have a little personal experience (namely a tiny clown that wouldn'y grow!), and when a fish, simply won't grow, they may have internal parasites.
There is a TON of info on these forums about skinny dz and its treatment, just search on that topic. There are all manner of treatment protocols using serial antiparastics and antibiotics (apparently, they can get secondary bacterial infections as a result of the parasites, so you need to use both). I have learned the hard way, and am now quaranteening new fish
Since clowns do not breed readily in captivity, many are wild caught, and harbor parasites which can stunt their growth. They need to be treated with meds which are detailed by the "long fins" (that's you guys with experience more than the relatively new ones...
That's a cool name don't you think? )

anyway, good luck with peewee.
Isn't it funny how we get a little more attached to the one that is struggling?

I'm not sure, but it could just be genetics. I have a few runts in my loach colony. I've been trying to bulk them up for about 4 years, yet they have only grown to about 2". I've tried new foods and a few de-worming meds (levamisole, Praziquantel, and currently trying fenbendazole flake food), but nothing has worked so far to get them to grow.

Perhaps in a few years or so we can have their DNA sequenced and learn the truth on why they are stunted.

Three of mine were purchased at the same time and have had identical conditions. All eat well and are nice and plump, but they are all different sizes now (after 2 years). One is very small, but is not bullied or chased. So I think they just vary a lot.