Beware of the sharp teeth of mangrove jack when handling them. They should be killed humanely by iki jime, or a firm knock to the head before placing them in an ice slurry after bleeding.
- Mangrove jack are greenish brown to red in colour, depending on water conditions. Juveniles have pale bars on the sides of the body and one or two blue lines on the cheeks.
- Male fish mature at around 4-5 years old (45-50 cm long), with females maturing between 5-8 years old (50-55 cm).
- Maximum age may exceed 31 years.
- Mangrove jacks occur over a large part of the tropical Indo-Pacific region, as far west as the Mediterranean Sea (probably travelling via the Suez canal).
- In Australia this species is found throughout our northern coastline from around Broome in the west to the central coast of NSW.
- Juvenile mangrove jacks spend the first few years of their lives in rivers and estuaries, ranging into freshwater reaches, while adults live on deeper offshore coral or rocky reefs to depths of at least 100 m.
- Tagging data shows that most of the offshore movements of mangrove jacks from the rivers occurs when they mature at between 40 and 55 cm in length.
Fish Size Common Length:
30-50 cm, maximum size 120 +cm and 15+ kg.