1. Appearance: The sauger has two distinct bulges, while the mackerel does not. In addition, the sauger has an iron-blue color and protruding lips as an adult, while the mackerel's body will have blue and yellow spots.
2. Habitat: The sauger lives mainly on steep reef slopes, seaway slopes, and lagoon reefs, in water depths ranging from 2 meters to about 60 meters. While the bluegill mainly inhabits flat sand or weedy areas near coral reefs or lagoon areas, lagoons and seaward reefs, with active water depths ranging from about 3 meters to 60 meters deep.
3. Price: The price of the sauger is higher than that of the mackerel, with the former being three to four times more expensive than the latter.
In short, the difference between sauger and mackerel is mainly in appearance, living environment and price.