Mangrove jack
Lutjanus argentimaculatus
Illustration: Bloom by Day
A heavy copper-red snapper with a blunt snout and a pair of obvious canines at the front of the jaw, unbarred as an adult and darker over the back than the belly. It lives hard against structure — rock walls, pylons, snags and mangrove roots — holding in the shade facing the current, and it does not drift into open water while you watch.
how to recognise it
- greenish brown to reddish with a silvery-white belly — deeper fish are red all over
- a slightly concave tail
- the scale rows on the back run roughly PARALLEL to the lateral line
- no bars on an adult
don’t confuse with
- Red emperor — the red emperor carries three dark red bands when young and never has the jack's parallel scale rows
- Red bass — red bass has a deep pit in front of the eye and its back scale rows rise obliquely
- Golden snapper — the golden snapper has a large black blotch above the lateral line under the front of the dorsal fin, and fine lines of reddish scale spots
Field marks read from Fishes of Australia, 2026-10-13. Our wording, their facts. Max size 150 cm TL.
facts
- habitat
- estuary
- size
- ~40 cm, to 150 cm
Max size from Fishes of Australia (150 cm TL); the typical size is Bluebird’s, not from a cited source
- records near here
- 12 at 1 of 6 spots
A count of occurrence records near these spots, not abundance. Records are where someone looked.
when it has been recorded
JFMAMJJASOND
A gap means no record in the sample, not absence.
the rule
QLD — Min: 35cm · Limit: 5
source
· verified 2026-10-10
NSW — no size limit · 5
source
· verified 2026-10-01
no closed season recorded for this species — that is not the same as open; check the official page
Rules checked 2026-10-13 against qld.gov.au
Rules change. Check before you dive.
Occurrence data: Atlas of Living Australia (ala.org.au), CC-BY 4.0.
Diver transect counts: Reef Life Survey (reeflifesurvey.com), CC-BY 4.0, supplied via ALA.
Target and protected species: Queensland tidal-water size and possession limits (qld.gov.au) and NSW saltwater bag and size limits plus threatened species lists (dpird.nsw.gov.au).
Habitat and size: Bluebird, approximate, from general knowledge. Not cited. FishBase is CC BY-NC and this app is commercial, so it is not used.
Description written for Bloom. RECORDS ARE WHERE SOMEONE LOOKED, NOT WHERE THE FISH ARE. A record count is a count of records near here and nothing else -- it is not abundance, and a species with few records is not rare. Absence of records is not absence of fish.
Diver transect counts: Reef Life Survey (reeflifesurvey.com), CC-BY 4.0, supplied via ALA.
Target and protected species: Queensland tidal-water size and possession limits (qld.gov.au) and NSW saltwater bag and size limits plus threatened species lists (dpird.nsw.gov.au).
Habitat and size: Bluebird, approximate, from general knowledge. Not cited. FishBase is CC BY-NC and this app is commercial, so it is not used.
Description written for Bloom. RECORDS ARE WHERE SOMEONE LOOKED, NOT WHERE THE FISH ARE. A record count is a count of records near here and nothing else -- it is not abundance, and a species with few records is not rare. Absence of records is not absence of fish.