Tiger Oscar has scales falling off

[Candilong]

I have a 9yr old red devil and a 5yr old tiger Oscar that share a tank. I noticed a few days ago that the Oscar has scales on his left side that are shedding. His fins and tail seem to be ok it's just his sides (mostly his left) that are affected. What should I do?

 

[dudley]

Sorry to hear about the Oscar!

Provide additional details please, tank dimensions, water change frequency and amount and your water test results for ammonia, nitrite and nitrate.

 

[TwoTankAmin]

Not a surprise here. The one piece of info needed here is tank size.

One of my go to fish info sites, seriouslyfish.com says this about the Behavior and Compatibility of Amphilophus labiatus (red devil):

One of the most downreight aggressive cichlids around, you need to know what you’re doing when attempting to keep a red devil with anything else, and that includes its own kind. In very large tanks this aggression becomes less of a problem, but by very large we are talking in excess of 1000 litres, which is simply beyond the reach of most hobbyists. In tanks of this size you can try it with other robust Central American cichlids, large Loricariids and other big catfish. Decent-sized fast swimming fish such as silver sharks, tinfoil barbs and the like are also a possibility. Keep a close eye on proceedings though, as some specimens will not tolerate any tankmates, and will systematically attack anything else in the tank. Keeping more than a single male is not usually an option in any tank, regardless of size.

https://www.seriouslyfish.com/species/amphilophus-labiatus/

Here is what they say about Astronotus ocellatus (oscar):

Although not especially aggressive for a cichlid of this size this species’ predatory nature dictates that it should not be combined with much smaller fishes.

Its adult size also precludes the possibility of it being maintained in a community in all but the largest private aquaria.

Potential tankmates include characids, anostomids, other cichlids, and larger loricariid or doradid catfishes.

https://www.seriouslyfish.com/species/astronotus-ocellatus/

Both of the fish can grow to a max size of over 13 inches Standard Length (i.e. not counting the tail). I am thinking the minimum size tank in ehich to keep these two fish together long term would be 350 - 500 gals. There would need to be large rocks and driftwood which break up sight lines and provide places for the lesser fish to hide when needed. This decor need to be too heavy for the fish to move.

If I am incorrect about what I suspect and Candilong has a 220 gal. or larger at this time, I apologize for assuming this was not the case. But I would still believe the damage to the oscar was caused by the RD not by an illness or parasite.

 

[Rbishop]

After some testing, I'd readily suspect the RD as the issue, even if small skirmishes that you may not observe. More info would be nice as dudley requested, as well as a tank shot showing decor. Any signs of excessive splashing out of the tank?

 

[FreshyFresh]

Welcome.

Need to know more info as suggested above.

I am also an oscar keeper. I keep an oscar and a green severum (only the 2) in a 75gal.