Scalloped hammerhead
Sphyrna lewini
Illustration: Bloom by Day
PROTECTED — look, don't shoot
The hammer is the whole animal: a wide flattened head, curved forward and notched in the middle, carried on a bronze-grey body. They pass in schools off headlands and pinnacles, high in the blue, and take no interest in divers at all.
how to recognise it
- the front of the hammer curves FORWARD and is notched in the middle — scalloped, which is the name
- a moderately tall, curved first dorsal fin
- the pelvic fins have an almost straight rear edge
- olive-green, bronze to brownish-grey above, paler below, with dusky pectoral-fin tips
don’t confuse with
- Great hammerhead — the great hammerhead has an almost STRAIGHT front edge to the head with only a slight notch, a very tall pointed first dorsal, and high pelvic fins with deeply concave rear edges
Field marks read from Fishes of Australia, 2026-10-15. Our wording, their facts. Max size 430 cm TL.
facts
- habitat
- pelagic
- size
- ~250 cm, to 430 cm
Max size from Fishes of Australia (430 cm TL); the typical size is Bluebird’s, not from a cited source
- records near here
- 8 at 4 of 6 spots
A count of occurrence records near these spots, not abundance. Records are where someone looked.
when it has been recorded
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A gap means no record in the sample, not absence.
the rule
QLD — No take
source
· verified 2026-10-10
NSW — No take
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.