Abalone
An abalone is a marine mollusc with a flattened, ear-shaped shell, belonging to the genus Haliotis.
Also known as: ear shell, Haliotis
How big is it?
10 cm · defined shell length
Also 3.937 in
Defined shell length · defined specimen
Typical recorded range: 5 cm to 20 cm.
A little perspective
Abalone vs Nudibranch: length comparison
The shell length of an abalone is approximately equal to the body length of a nudibranch.
An abalone is a marine mollusc with a flattened, ear-shaped shell, belonging to the genus Haliotis.
A nudibranch is a soft-bodied marine mollusc, often brightly coloured, commonly known as a sea slug.
Both rulers start at the same zero and share one linear scale. Artwork keeps its original proportions.
Measurements, assumptions & sources +
Abalone
Defined shell length: 10 cm; defined specimen; range 5 cm–20 cm.
A defined adult abalone with a 10 cm shell and 200 g live mass. Species and age vary widely; the calibrated shell length excludes the soft foot and epipodial tentacles.
NOAA Fisheries — White abalone
The marked defined shell length is calibrated. Unmeasured illustration details are representative.
Nudibranch
Defined body length: 10 cm; defined specimen; range 5 cm–15 cm.
A defined 10 cm dorid nudibranch specimen. Species range from millimetres to many centimetres; rhinophores and gill plume are included in the illustration but not the nose-to-tail calibration.
Smithsonian Ocean — Nudibranchs
The marked defined body length is calibrated. Unmeasured illustration details are representative.
Use the visual comparison to explore its scale, then check the measurements and sources.
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Why this measurement?
Why we use 10 cm
We compare the shell length of an abalone. This is an illustrative comparison value, not a claim that every example is the same. The recorded range is 5 cm to 20 cm.
A defined adult abalone with a 10 cm shell and 200 g live mass. Species and age vary widely; the calibrated shell length excludes the soft foot and epipodial tentacles.
The marked horizontal span follows the measured feature, not the edges of the image. How calibrated comparisons work →
Recorded properties
Dimensions and measurements
| Property | Selected value | Recorded range | Basis |
|---|---|---|---|
| 10 cm | 5 cm to 20 cm | defined specimen | |
| 200 g | 80 g to 500 g | defined specimen |
Around this scale
Explore nearby values.
Compare examples with lower, similar and higher values. Each card names the measurement being compared.
Nearest lower valueLiving thingsMouse9 cmBody lengthA mouse is a small rodent with a pointed snout and a long, thin tail.
Around the same scaleLiving thingsNudibranch10 cmDefined body lengthA nudibranch is a soft-bodied marine mollusc, often brightly coloured, commonly known as a sea slug.
Nearest higher valueLiving thingsGeoduck17 cmDefined shell lengthA geoduck is a large burrowing marine clam with a comparatively small shell and a very long siphon.Sources and method
Want to check the number?
The source records and measurement method remain available for inspection.
- NOAA Fisheries — White abaloneAbalone shell anatomy and adult size variation; the atlas uses a defined multi-species comparison specimen.
There’s always another scale
Follow your curiosity.
Living thingsQueen conch25 cmThe queen conch is a marine mollusc native to the Caribbean and western Atlantic, recognised for its spiral pink shell.Living thingsGeoduck17 cmA geoduck is a large burrowing marine clam with a comparatively small shell and a very long siphon.Living thingsNudibranch10 cmA nudibranch is a soft-bodied marine mollusc, often brightly coloured, commonly known as a sea slug.
Everyday thingsPomegranate10 cmA pomegranate is a round fruit from the Punica granatum tree, containing many edible seeds surrounded by juicy pulp.
SportShuttlecock8.5 cmA shuttlecock is a feathered projectile used in badminton, designed to be struck by rackets.
PeopleHuman heart12 cmA human heart is a muscular organ that pumps blood through the circulatory system.
Living thingsMantis shrimp10 cmA mantis shrimp is a marine crustacean that hunts using specialised limbs to strike or spear prey.
Everyday thingsPear11 cmA pear is a sweet, edible fruit produced by trees of the genus Pyrus, commonly eaten fresh or used in cooking and baking.