Shark mackerel
Grammatorcynus bicarinatus
Illustration: Bloom by Day
A slender blue-green mackerel with a very large eye and, uniquely, TWO lateral lines — the second loops down behind the pectoral fin and rejoins near the tail. It comes through fast and high over pinnacles and wrecks, often in a tight group.
how to recognise it
- TWO lateral lines: one runs from the gill cover to the tail, and a second drops steeply behind the pectoral fin, runs along the lower side and rejoins the first near the tail
- metallic bluish-green above, silvery below
- small black spots scattered on the belly
- a slender mackerel with a large eye
don’t confuse with
- Spanish mackerel — the Spanish mackerel has ONE lateral line and wavy grey bars down the side
- School mackerel — school mackerel has one lateral line and large grey blotches
- Spotted mackerel — spotted mackerel has one lateral line and rows of round spots
- Grey mackerel — grey mackerel has one lateral line and is nearly plain as an adult
Field marks read from Fishes of Australia, 2026-10-15. Our wording, their facts. Max size 130 cm FL; 12.3 kg.
facts
- habitat
- pelagic
- size
- ~90 cm, to 130 cm
Max size from Fishes of Australia (130 cm FL; 12.3 kg); the typical size is Bluebird’s, not from a cited source
- records near here
- 2 at 2 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: 50cm · Limit: 10
source
· verified 2026-10-10
no NSW rule listed — check before you dive
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.