Inaccurate on so many levels. Note the spaded tail at one point.
One of the more well-known connections between dragons and fish is the story of the Dragon Gate. If a carp jumps over a certain waterfall, it will become a dragon. One version involves a carp tricking a dragon guarding the gate, then jumping over. However you decide to play it, the theme of a humble fish becoming a dragon is invoked on Boys' Day (in Japan) to ensure that one's son will be successful, just like the carp that jumped the Dragon Gate. (Maybe it flipped the dragon the bird while doing so. Nobody knows.)
A number of fish, such as the Asian red arowana (Scleropages formosus), are also draconic by association. There are actually quite a few different localities of arowana in Asia, but this will focus on the 'chili red' sort. As with almost everything else awesome, the red varieties of arowana are all native to Indonesia. These have been so over fished that the species had to be placed on the Endangered list. Its habitat is also being depleted, but the pet trade is far more threatening. People want these fish specifically. The prices for them run into 6 digits.
So, what makes this fish such a big deal? Aren't people content with koi?
...Wow. WOW. THAT is a fish that looks like it could become a dragon at any second! One Asian arowana fan describes the fish as "flying through the water like a dragon flying through the sky." Its regal appearance, large size (around 3 feet; that's not even the family's biggest member!) barbels (whiskers on a fish), and gleaming red scales all make it look like China's favorite legendary creature. No offense to the carp; it's determined, but damn if these red arowana do not look like a step between fish and dragon. HOLY CARP!
There are a number of reasons that people want red arowana, but the main one is that they look like dragons. Other explanations include feng shui (since water is a yin body, a fish with fiery, yang coloration must be added to balance it out), general good luck (which is again linked to the dragon), and fish being able to detect guests with ill will or dying in their masters' steads. Never mind the Chinese Cinderella story that some of us were forced to read for writing classes.
More awesome arowana pictures here. Please support well-meaning farms if you want an arowana; otherwise, you are violating CITES regulations. They also get huge, so be prepared to get a large tank.