hello, straight to subject;

opening mouth wide; my oscar sometimes opening his mouth so wide "as if" he is yawning. i really can't find the right words since his (every fish maybe) mouth physically different than human mouth... it seems like his jaw has an extra joint normally stays folded? now, when i say opening wide i mean that, using that extra joint as well. is he just exercizing or is this a sign of something bad?

changing color; can you say oscar (tiger) fish changing their colors in order to show how they feel? what are your observations? possible situations would be; afraid, pissed off, stressed ("i need more space here", "i feel weak", "water stinks here", "you name it", content, excited, horny etc. etc. oh, and do you think water bed has an effect on their darkness? i heard if white gravel, quartz and such stuff they tend to stay lighter than their usual(?) ?

leaning down to his side: i pretty much figured the biggest reason out there... whenever he eats a bit too much he does so. BUT what i want to know is does he suffering stomach pain or something? we humans as well, when eat so much tend to lie saying baaaaa... cause if it's not the latter i will feed him less than my usual.

there are various reasons why an Oscar, or any other fish might yawn.they could be merely stretching their jaw muscles. They could be trying to expel an irritant in their mouth, or in the gills. Yawning can also be connected to hype nitrate levels so always to a water test if your fish does it a lot. If the fish only does occasionally and your water is okay, I should not worry.

changing colour is quite normal in the animal kingdom. Many species of fish will change colour for reasons such as aggression, breeding, stress, matching their surrounding appearance. However, the colour of the fish can often indicated state of health so fish that go very pale and stay like that may often have something wrong with them. It is something to keep an eye on but don't worried every time your fish changes colour because they can do it quite a lot.

Yes, Oscars often do lean to one side. I've had Oscars that do it, I've not noticed it lately though so it could well be an Oscar is not feeling is very well, or is a little stressed out. From my experience, Oscar should not b inactivee for too long. I often notice my Oscars lazing around and just sitting on the bottom of the tank. However, they will move to investigate movement outside the tank when they see me. If an Oscar was to lay on the bottom of the tank for a long while, I would be a little worried and want to find out why it is doing it.

my oscar did this yawning thing when i was watching him maybe two days ago several times but never seen him doing it again... guess he was trying to expel an irritant as you suggest.

no, the case is definitely not the staying pale for a long time. he does gets black, i usually catch him black when i just enter the room but then he gets lighter and lighter, closer i am, lighter he is. i understand fish do change their colors a lot yet i'm trying to understand if he is afraid of me or not... he definitely see me as the source of food yet i suspect if he really trust me. he has guts. he comes bashes my finger while trying to get frozen fish and stuff but right after he gets what he needs he is darting back and staying away eyes on me chewing... is this usual? what you might suggest to gain his trust? or is this just his nature and not going to change?

a bonus question: i don't remember where but i've read siamese tigerfish could be a tank mate for oscars.



but i also read they need brackish water. what do you think?

Do Oscars possess emotions such as liking and disliking people? I've often heard people say that their Oscar freaks out when they see one person and it's perfectly okay with somebody else. Personally, I think that fish have not evolved enough to actually have motions. So in other words, I don't think your Oscar will look at you as if your dog would. out of all the Oscar's I've ever keped, I have never noticed them behave any differently with anybody who has ever stood in front of the tank, or fed them. As long as they are getting food, they would accept pellets from Beelzebub's himself.

Fish do actually see in colour so there may be certain colours that might frighten a fish, hence wearing camouflage type colours when angling.

As for the Siamese Tiger fish, I believe there are various types, some of them favouring brackish/fresh water, ever is just fresh water. I think yours is okay and just fresh water. they can live in harmony with larger species of fish However, these fish do get very big so if you are going to keep them with the Oscars, you must have an adequate tank, well over 100 gallons for one of these and another Oscar

hmm... i don't think "trusting" and "being scared" can be categorized as liking and disliking. or an oscar thinks;

1. i know this human. gives food. good for survival.
2. i also know this human don't bite my fins or whatever.
3. (now i'm not sure about this one) so no need to be scared when this person around ?

but.....

one week passes, time to clean tank. now that human taking off stones, creating sandstorms, sucking their atmopshere with stuff... scary things? shows you're powerful if not already known. also what this human exactly trying to do? not enough brains... just scary...

guess that's how it goes.

i have a 70 gallon tank... well, gotta upgrade it then. thanks for all info.

I think the Oscars are they way they are because of the way they have been bred initially. Some of my fish are very skittish and will shy away if I put my hands up to the tank. Oscars will associate movement outside of their tank with food, that's absolutely certain. I think they get used to situations such as feeding times through repetition. not every fish is the same and I've heard all sorts of wonderful and weird stories about Oscars so it's sometimes difficult to say exactly what is going on.