Hey guys,

I have recently been noticing some strange behaviour involving one of my Oscars. He/She has a strange habit of eating pebbles. I understand that a lot of different fish consume pebbles and spit them back out, however in this Oscars case he/she doesn’t spit them out.

First Observation- Oscar was bottom feeding when he/she seemed to have pebble stuck in his/her mouth. During this, it looked like it was sulking and sitting on the bottom of the tank. However he/she ended spitting them out, after many attempts.

Second Observation- Oscar’s lower abdomen began to swell abnormally and looks pretty uncomfortable.

Third Observation- Oscar swims normally, however is frequently excreting the pebbles as he/she swims.

I have read the bloating section of the website and the symptoms fit the description. I am just concerned about the Oscars overall well being because I could imagine that this must not be too healthy. However according to my third observation the pebbles are successfully passing through his/her digestive track. There is no visible blood or hemorrhaging when the excretion occurs. On a good note my other Oscar knows what he/she can eat and has not visible abnormal bulge in the lower abdomen.

My questions;

Has anyone else observed this behavior?

If so, what ways can I prevent this (Hopefully without removing all the pebbles)?

Tank Size:
Tank: 4 ft (L) x 36cm (W) x 48cm (H)

Water Quality:
Temperature: 28⁰C
PH: 7.0(Stabilizer Used)
De-chlorinated

Standard Aquarium light and canister filter.

Fish:
I have 2 tanks running, if getting too crowded I can transfer some of the tank mates.
2 Oscars 4-5"
2 Silver Dollars
2 Clown Loaches
1 Synodontis Catfish

Water Changes:
20% Volume
1-2 Times a week, includes gravel siphon.

Thankyou for all your help and support.

Chenga

I'm not sure if the fish would actually eat pebbles, are you absolutely sure this is happening? Oscars chew their food using teeth at the back of their throats, they are not going to be able to chew a stone up.

It is quite normal for them to move the substrate around using their mouths so that shouldn't alarm at all. As for the swelling in your fishes abdomen, that could be caused by quite a few factors, this is more of a symptom rather than a disease or illness. Could you possibly take some photographs for us? Also, is your fish eating?

They are all eating fine. The oscar is definetly consuming the small pebbles, not chewing, but whole. They come out of its waste. It looks like soon as the pebbles pass the bloating goes down. Today when I was about to feed them the oscar excreted 2 small pebbles.

If this is actually the case, I would remove the gravel before one doesn't pass...

i had been eating my fish before, but none of my oscars had stone or pebbles
in their stomach though they used to scoop and move all the substrates.
(note: i am no longer grilling my fishes unless accident happen like
jumping out of tank)