my oscars mouth is stuck open

Big fish eats little fish, it's a fact, why the surprise?



That is the nature of an Oscar. No, they don't make good tank mates with just about anything. Having an Oscar is more than just having a big fish. I have owned several and still have 2 left. I know from experience what I can and can't do with them, but I researched before getting my first ones. You can have tanks mates but they have to be larger or meaner.

The fact that he can't close his mouth raises several possibilities. How a tendon on the outside of a jaw will get severed is beyond me, but that's your DX not mine. I would look more to the possibility of a broken or dislocated jaw. There is also the possibility of a dorsal spine being impaled and not allowing the jaw to close. Anything is sheer speculation without seeing it firsthand. Heat and salt only work well with parasites and not bacterial infection. If anything, heat can make them worse.

The OP needs to perform a very careful and full exam to try to find the cause.

BTW - the only reason I have 2 is because I kept them instead of rehoming. I take them from people that get in over their heads, bring them to good health and then rehome. And yes, I have tank mates in with them that work.

Feeling argumentative, huh?

I've had oscars before, too. They never got that aggressive but then I never put them one on one into a tank with another fish, which doesn't often lead to good results with cichlids.

Oscar is 4 inches, plec is 2.5 and you don't find it unusual he tried to swallow it whole? I've never seen one have much interest in a plecostamous, let alone try to swallow one that's only and inch and a half smaller.

Sure oscars can have tank mates I never had an oscar kill anything. This oscar however sounds out of control.

Yes pulling out a spine could poke it through anything, but broken or cut the diagnosis is not good. If he had it that far down I doubt he will live but I get surprised at the mishaps some fish can survive.
 
Feeling argumentative, huh? No, I just happen to know a bit about Oscars.

I've had oscars before, too. They never got that aggressive but then I never put them one on one into a tank with another fish, which doesn't often lead to good results with cichlids. I do mix them with cichlids and others. You need to understand a lot more than you do now to be able to do it successfully. Right now I have a 10" Oscar in with a 4" cichlid and a 13" pleco that works well.

Oscar is 4 inches, plec is 2.5 and you don't find it unusual he tried to swallow it whole? Not at all unusual. Oscar teeth are located in the back of the throat called the phalanx, not in the mouth. It requires them take in as much as a fish as possible to be able to chew it. I've never seen one have much interest in a plecostamous, let alone try to swallow one that's only and inch and a half smaller. Any fish that is smaller and slower will become lunch if they can.

Sure oscars can have tank mates I never had an oscar kill anything. This oscar however sounds out of control. No different than any other.

Yes pulling out a spine could poke it through anything, but broken or cut the diagnosis is not good. If he had it that far down I doubt he will live but I get surprised at the mishaps some fish can survive.
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Will his Oscar survive? Probably not. Cause of death will likely be from suffocation. Can they survive a broken or dislocated jaw? Yes, sometimes.
 
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Sickbum is right, it is unusual for an oscar to take a fish only 1 1/2" smaller than itself. IME, they usually have better judgement than that. However, you never now what a particular oscar is going to try to eat until its in the tank with them.

Here's the current stocklist on my 225 gallon tank:

4x oscars (Astronotus ocellatus) - one 13" red tiger, one 11" red, and two albino tigers at 11" and 9"
1x green terror (Andinoacara rivulatus) - 8" male
1x striped pike cichlid (Crenicichla strigata) - 9" and still growing...
1x banded leporinus (Leporinus fasciatus) - 9"
2x four-line pimelodus (Pimelodus blochii) - 9" each
1x common pleco (Hypostomus plecostomus) - 12"+
1x sailfin pleco (Pterygoplichthys gibbiceps) - 6" and growing...

The three largest oscars could fit the sailfin pleco in their mouths if they worked at it. They are well fed and there is plenty of cover in the tank, so they don't even notice him. They are always rearranging the driftwood in the tank and reestablishing their own pecking order.

The big thing here is oscars are probably as individualistic as any fish commonly kept in aquariums, and they explore their world with their mouths. They are curious and intelligent, as far as fish go. If you want to keep O's with other fish, you need a big enough tank with cover for the other fish and things to keep the O's occupied. The oscar was either very hungry or bored to swallow that pleco. Personally, I'd guess the latter, in a too small tank with little else to keep the O's attention. The result is a tragedy for both fish.

After 28 years in the hobby, I wouldn't have hesitated to add a 2 1/2" pleco with a 4" oscar, either, so don't fault yourself, jason. I would not have done it in a 29 gallon tank, however, and would have made sure to add plenty of cover. But you already know that. ;)

Pharyngeal teeth are an anatomic adaption to hold prey and have little to do with actual prey selection. If it was hungry enough, the oscar (or any other predatory fish, for that matter) would have tried to swallow the pleco with or without pharyngeal teeth. The teeth in and of themselves don't drive predation, and are irrelevant to this conversation.

If half the pleco is still in the oscar, all you really can do is wait. Salt and antibiotics may help prevent secondary infection if the O hasn't suffered any internal damage. Raising heat may be counterproductive, as higher temperatures reduce dissolved oxygen in the water, and higher oxygen levels are probably in order to aid healing.

On a side note, I had an oscar years ago that decided he wasn't going to eat a feeder goldfish after eating the other five I put in the tank. The goldfish ended up being 8" long when I finally gave him away for a pond. Never figured out what was special about that goldfish.

WYite
 
Let's keep in mind, those sizes were estimates. We also only know it is a 'pleco'. Not exactly which breed (although common pleco is likely).

Speculating on whether this was likely or not isn't really useful at that point. We are assuming this is a Sailfin and Oscar of roughly similar size. For all we know it could have been a 2" shortfin breed of pleco and a 5" oscar.
 
With the right of amount of Oscars...over the right amount of time...under any conditions provided....one will eventually eay something twice their size.
 
well he has fully regained his energy and apatite, but his mouth is still stuck open and it doesn't seem like he can eat his food. his mouth moves a little but doesn't seem to close enough to get food.
 
sorry to hear that. just keep up with the water chages and hope for the best. maybe you could take him out and examine him to see if you can close his mouth without hurting him. sounds dislocated.
 
well an update on my pet oscar, he has fully recovered and his mouth is shut. letting nature set its course for him was the right idea, he's his splashy happy self again. now i know to keep smaller fish out of the tank
 
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