Identification
The chub mackerel closely resembles the Atlantic mackerel but differs in key details. The back shows less sharply defined crossbars and the flanks have vague dark spots below the lateral line — absent in Atlantic mackerel. The eyes are notably large. A swim bladder is present (absent in Atlantic mackerel). Reaches 50 cm.
Ecology
A warm-water species living in large schools in tropical and subtropical waters worldwide. In Europe, common in the Mediterranean and along the Iberian coast. Feeds eagerly on small fish, shrimp, and zooplankton. Like all mackerels, a fast, voracious hunter.
In the Netherlands
The chub mackerel is appearing more frequently in the North Sea, presumably due to rising water temperatures. Where the species was a rare vagrant twenty years ago, sightings are now regular. A clear example of the subtropicalization of the North Sea.
