They will change colors when they are hungry or stressed out.
If they stay a light color for a day or more this could be the first sign of a disease though.
they can eat slugs worms live fish and dead fish bugs .
It is generally not advisable to place an Oscar fish with yellow tangs. Oscars are aggressive freshwater fish, while yellow tangs are peaceful saltwater fish, making them incompatible in terms of habitat and temperament. Mixing different species from different environments can lead to stress and aggression, ultimately harming the fish. It's best to keep them in their respective environments for their health and well-being.
If the fish has distended sides and belly and sometimes seems to have swim bladder problems. Then it may have 'bloat'.
Oscar is a type of fish so he is a Oscar fish
For exactly the same reason your tummy gets bigger when you pig out and eat too much. The food/feeder fish have to go somewhere once they are swallowed so the Oscar has to swell up a bit until the digestion process is over.
Female Oscar fish will appear rounder in the belly area if they are pregnant. Look for a more pronounced bulge near the anal vent. Additionally, the female may exhibit changes in behavior such as increased aggression or territoriality.
Oscar fish can be caught in the canals of Southern Florida.
Oscar fishes breed is Oscar
The small black bird with a yellow belly is called a Yellow-bellied Flycatcher.
The yellow belly lizard
Not totally sure but if the black Oscar is bigger that could be the reason
The small green bird with a yellow belly is called a Greenfinch.