Page "Scombridae" Paragraph 1

Scombrids have two dorsal fins, and a series of finlets behind the rear dorsal fin and anal fin.

The caudal fin is strongly divided and rigid, with a slender, ridged, base.

The first ( spiny ) dorsal fin and the pelvic fins are normally retracted into body grooves.

Species length varies from the 20 cm length of the island mackerel to the 458 cm recorded for the immense Atlantic bluefin tuna.