All of the photos show a silver arowana... looks like it might be a wild caught aro, since it has thick red fins and a darker (tanned) overall color. But it is 100% silver. Nice fish!
i'm not into South American Arowana much, but it look like a low quality black arowana, the 2nd and 3rd pictures is a black aro for sure because its body is smaller than the bottom fin,they're very fragile, die easier than a silver.
i think that's how u tell the different between silver and black/blue beside the colors. I'm not an expert.