Need some help please folks. I have a 3.5" Oscar thats getting thinner not fatter. I've had him a month and he was fine when I got him. He's got a good appetite and so far the only thing he doesn't like is krill. The bulk of his diet is Hikari Cichlid Gold mini pellets, supplemented with prawns, chopped earthworms, bloodworm, mealworm, apple and melon. I watch him eat and hand feed him most things so I know the other fish aren't getting all his food. Behaviour wise he still charges to the front of the tank when he sees me, but spends the rest of the time in 'his' bit of the tank. He's keeping his fins close to his body all the time and pooing alot. That varies between long white or green strands. If anyone has any ideas on whats wrong I'd be glad to hear them and will take all the advice I can. I'm worried I might lose him.
Tank: 260 L, Fluval 405 - 850 L/ph, Fluval 3 Plus - 700 L/ph, running for 6 years.
Tankmates: 1 Plec 6", 4 P Pictus Cats 5-6".
Water: pH: 7
GH: 5
KH: 3
NH4: 0
NO2: 0
NO3: 10 mg/L

CHECK FOR PARASITES LIKE TAPEWORM

a picture of the fish could help us evaluate if your fish needs
additional attention..... perhaps it is thin in your look but may
be fine with us...how could you say it is thinner? do you have another
oscar to compare with?

Tried uploading a photo but couldn't get it to work, I'll try again. He's the only Oscar I've got but I have kept them before so got a good idea of what he should be like. He's definately thin, very sunken right behind his head, belly tucked up, his head looks too big for his body. He's worse this morning, seems too be having a hard time swimming, resting on the bottom and tilting from side to side like he can't balance himself. Really worried bout him now he looks so much worse. Tested water again this morning after yesterdays water change (changed 56L) parameters all same as yesterday, NO3 gone down a bit <5 mg/L.

starting to sound like a swim bladder infection? can he maintain a given high in the water without sinking or floating or dose it need to work hard to stay at the level? if its swim bladder infection the faster you treat with the right med the better chance you have of recovery.

Swim Bladder Problems

Swim bladder problems are caused by bacterial and viral infections, or hereditary problems. The swim bladder helps the fish to control its buoyancy, allowing it to maintain its position in the water. Internal bacterial infections can affect its function, making it difficult for fish to maintain position. Fancy goldfish with their short body form are particularly prone to this problem.

Treatment for Swim Bladder Problems

Raising the temperature to 27°C (80°F), adding aquarium salt to a level of 0.5% (5 gm per litre), and using a treatment such as Interpet's Swim Bladder Treatment No.13 is recommended. You should also feed sparingly.


this may help decide if it is swim bladder
www.fishyfarmacy.com/fish_diseases/swim_bladder.html

Right got photos finaly, here they are!!!

Poor Little Guy.. I hope he gets better.

your oscar is indeed slim due to malnourishment but not sick....the pooh shows its
digestion system is still good. i suggest you give him/her plenty of worms, crickets,
or sliced beef heart...he/she can recover soon....just make sure you keep the water
in good condition

Thanks all, just don't understand how he could have become malnourished. He's on 3 meals a day, Hikari Cichlid Gold 2x a day and a supplementary meal of either chopped earthworm, bloodworm, mealworm, prawn, apple, melon etc. As I said he's hand fed his sup meal and I feed until he no longer 'Attacks' his food. If I'm not feeding enough please let me know how much and how much more often I should feed him. Adore this little guy and hate seeing him like this.

yes...you feed him/her well but for sure we do not know how was he/she kept before
you got him/her.... how did it looks when you first got it?

keep on feeding with 3 minutes rules, 3X while still juvinile...and once
its belly shows bloaten... it will recover and will grow fast

Thanks Paul. He looked fine when I got him, not hugely fat but not skinny. Photo shows him on his 2nd day home.This just seems to have happened so quickly.
. i940.photobucket.com/albums/ad245/oscarmad/Fish/photos020.jpg

totally agree with paul on this one, should be looking healtheir soon. keep checking water, but like i say think paul has yr back on this one.