Sounds like a gas bubble or erupted swim bladder.
If by Dragon fish you mean Arowana then, no it is not normal for one to be swimming upside down. They grow into really big fish (over 40 inches long) so I hope you have a really big tank more than 8 feet long to house it in.
when a koi fish swims upstream and makes it it turns into a magnificent dragon thus a koi fish swimming upstream symbolizes overcoming adversity and realizing/fufilling our fullest potential
A koi would generally be depicted swimming upstream, not down. According to Japanese legend, once a koi swims over the falls at the 'Dragon Gate on the Yellow River' it would be transformed into a dragon. As such, the koi swimming upstream is a symbol of Ambition.
if it is not swimming it is dead!
Fish that have a stomach, generally secrete stomach acid (HCl). However, not all fish have a stomach. For example carp have no stomach and thus no stomach acid secretion.
Yes, fish can be seen swimming in the ocean.
Two fish. One fish swimming going up an another swimming down.
A fish that acts crazy
Well koi fish symbolise strength and courage, and the legend and myth behind the koi fish is that it swims upstream to turn into a dragon. The Dragon symbolises the end of a journey and overcoming the obstacle you faced. Therefore a Koi swimming upstream symbolises faceing a problem and being on a quest to put an end to it. A Koi swimming downstream symbolises that it has allready overcome the problem, people often get this to symbolise the end of an ordeal.
The black dragon fish is indead endangered
A fish that is swimming vertical is usually ill or stressed and could die if not treated
it means your swimming in a pool with dirty water and fish.....get out!