The pangasius have a shorter distance from the tip of their snout to the base of their dorsal fin. They also have almost no lump on top of their head in comparison to the ID sharks which have a large lump right above their head. Not really large just slight, but the pangs have just a smooth head. The pangs are also much thicker at a large size than IDs. Most pangasius species look very similar at a small size. Even hard to tell adults apart unless you know what you are looking at. This is what Necrocanis is telling me anyway. He's sitting right next to me lol. I just using his computer to check things out!