It's an air bladder but is if not much like the common mackerel. The Pacific chub mackerel is caught in substantial numbers off the coast of California, even though the Atlantic chub mackerel is commonly dispersed along both of those coasts on the North and South Atlantic. japonicas species as https://atlantic-mackerel-pregnan39198.thenerdsblog.com/37464162/top-latest-five-atlantic-mackerel-en-espanol-urban-news