utjanus argentimaculatus, the mangrove red snapper (commonly called mangrove jack within Australia), is a species of snapper native to the Indian Ocean and the western Pacific Ocean from the African coast to Samoa and the Line Islands and from the Ryukyus in the north to Australia in the south. It has also been recorded from the coast of Lebanon in the Mediterranean Sea having reached there from the Red Sea through the Suez Canal though it is not established in the Mediterranean. Coloration of the mangrove red snapper ranges from burnt orange, to copper, to bronze and dark reddish-brown, depending on its age and environment. Younger fish caught in estuarine areas are often darker than older fish taken from offshore reef areas, and exhibit lighter vertical bands down their flanks. As its name implies, the mangrove red snapper is commonly found in mangrove-lined estuarine systems, although is known to migrate to offshore reefs to spawn. For fishermen, the telltale sign of a hooked mangrove red snapper is the explosive run for cover once the bait (or lure) is taken. Many fish (and again, lures) are lost once they reach the protection of the snags as a result of their initial burst of speed. As they mature, mangrove red snappers move into open waters, sometimes hundreds of kilometers from the coast to breed. These larger fish are sometimes caught by bottom-fishers with heavy tackle, though they still remain difficult to land due to their speed and proximity to sharp reef bottoms.
The mangrove red snapper is a highly regarded table fish with firm, sweet-tasting, white flesh. While often a nuisance species when targeting the infamous barramundi, many fisherman rate the eating qualities of the jack higher than its more famous neighbour.