Trachurus novaezelandiae, better known as the Jack mackerel, are found in vast schools throughout New Zealand and Australia. They are a pelagic species found mostly in mid-water or near the bottom in shore out to at least 300m.
The average size of fully grown adult jack mackerel is between 30 and 50 cm. Jack mackerel are relatively slow growing reaching maturity at 6 to 7 years of age. Big specimens can be as much as 30 years old.