Also known as Cigarfish, Indian Scad, Kingston, Mackerel, Mackerel Roundscad, Robin, Round Robin, Round Scad, Shortfin Scad, Trevally.
Found in fast moving schools along shallow reef edges over deep clear oceanic waters often close to islands.
They feed on zooplankton.
Length - 35cm
Depth - 0-400m
Jacks are fast swimming fish that can roam over great distances. The larger fish hunt other fish and the smaller fish eat zooplankton. In turn they are hunted by large Tuna and Dolphins. Ref: https://www.fishbase.se/summary/993