A fish should not look as though it is fighting for oxygen. If you notice that you Oscar has started to struggle with its breathing then there are a few things to do at first. The fish is still moving it s mouth though.

Oscar fish Firstly is your water in good condition It s just a constant opening closing but doesn t seem to be a frantic gasping. I m wondering if something is wrong with it s mouth It s swimming around the tank eating etc. So it doesn t seem to be acting weird otherwise. Oscar fish open their mouths wide when they engage in the act of mouth fighting. Although this is most common among two males a male and female often do this before mating. If there are no other It may still be open from him swallowing the pleco. Even though the tail is now gone from view doesn t mean the fish is all the way down.
I d give it some time and keep an eye on him. His mouth being stuck open and not allowing him to eat during feedings will kill him but there shouldn t be a problem if he can still eat. Fishes open mouth to take water like we humans do but they don t take water to quench their thirst. If not to quench their thirst then why do they take Water contains dissolved oxygen. Water from the mouth goes to the gills where dissolved oxygen is absorbed and water is flushed out. He hasn t been able to close his mouth for almost two weeks and he is getting very skinny compared to my other one. I pulled him out of the water and tried to see if there was something stuck in his mouth and i am not able to find anything. I was physically able to push his mouth shut but it just comes back open.
He desperately tries to eat but he just can t keep any of his food down. The only time i see my lei 8 breathing with mouth opening and closing is when it s just had some food krill chunks of bloodworms bigger size pellets . After about 10 minutes or less it stops. That or when it gets spooked for whatever reason. Lockjaw seems a bit of a catchall term for a fish that either cannot open or close the mouth. Rarely a fish might get tetanus which is what we usually think of with the term lockjaw but if that s the case there is nothing to be done and the fish will die.

South Haven Tribune - Schools Education3.18.19South Haven
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courtweek.com - Archives 2011November 1 2011The Law of
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South Haven Tribune - Schools Education3.18.19South Haven
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courtweek.com - Archives 2011November 1 2011The Law of
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courtweek.com - Archives 2011November 1 2011The Law of
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