Sea angel
A sea angel is a small, transparent swimming sea slug with wing-like appendages, found in cold ocean waters.
Also known as: Clione limacina, naked sea butterfly
How big is it?
2 cm · defined body length
Also 0.7874 in
Defined body length · representative specimen
Typical recorded range: 1 cm to 4 cm.
A little perspective
Sea angel vs UK 1p coin: length comparison
The diameter of a UK 1p coin is about 1.02 times the body length of a sea angel.
A sea angel is a small, transparent swimming sea slug with wing-like appendages, found in cold ocean waters.
A UK 1p coin is the one-penny denomination of the decimal pound sterling circulation coinage.
Both rulers start at the same zero and share one linear scale. Artwork keeps its original proportions. Horizontal rulers compare the selected spans; vertical brackets also identify height on the artwork.
Measurements, assumptions & sources +
Sea angel
Defined body length: 2 cm; representative specimen; range 1 cm–4 cm.
A defined 2 cm adult sea angel modelled on Clione limacina. Body length excludes the extended wing-like parapodia; species, maturity and posture change the span.
The marked defined body length is calibrated. Unmeasured illustration details are representative.
UK 1p coin
Specified diameter: 2.03 cm; specified.
Copper-plated steel UK 1p: 20.3 mm diameter, 1.65 mm thickness and 3.56 g mass. Bronze pennies have a published thickness of 1.52 mm; both materials share the stated diameter and mass.
Royal Mint — 1p specifications
The marked specified diameter 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 2 cm
We compare the body length of a sea angel. This is a representative comparison value; individual specimens or conditions can vary. The recorded range is 1 cm to 4 cm.
A defined 2 cm adult sea angel modelled on Clione limacina. Body length excludes the extended wing-like parapodia; species, maturity and posture change the span.
The marked vertical 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 |
|---|---|---|---|
| 2 cm | 1 cm to 4 cm | representative specimen |
Around this scale
Explore nearby values.
Compare examples with lower, similar and higher values. Each card names the measurement being compared.
Nearest lower valueEveryday objectsUS penny1.905 cmDiameterA US penny is a copper-plated coin worth one cent in United States currency.
Around the same scaleLiving thingsBird’s nest fungus2 cmDefined fruiting-body heightBird’s nest fungus is a small fungus whose fruiting body resembles a tiny nest containing spore-filled capsules called peridioles.
Nearest higher valueEveryday objectsUK 1p coin2.03 cmSpecified diameterA UK 1p coin is the one-penny denomination of the decimal pound sterling circulation coinage.Sources and method
Want to check the number?
The source records and measurement method remain available for inspection.
- Smithsonian Ocean — PteropodsSea-angel identity, swimming anatomy and broad size variation.
There’s always another scale
Follow your curiosity.
Living thingsSea butterfly5 mmA sea butterfly is a small marine snail that swims using wing-like extensions and has a delicate coiled shell.
Living thingsNudibranch10 cmA nudibranch is a soft-bodied marine mollusc, often brightly coloured, commonly known as a sea slug.Everyday thingsUK 1p coin2.03 cmA UK 1p coin is the one-penny denomination of the decimal pound sterling circulation coinage.
PeopleHuman eyeball2.4 cmThe human eyeball is the globe-shaped organ that receives light and begins the process of vision.Living thingsBird’s nest fungus2 cmBird’s nest fungus is a small fungus whose fruiting body resembles a tiny nest containing spore-filled capsules called peridioles.Everyday thingsUS penny1.905 cmA US penny is a copper-plated coin worth one cent in United States currency.
Living thingsHoneybee1.5 cmA honeybee is a social insect that lives in a colony and gathers nectar and pollen from flowers.
SportSquash ball4 cmA squash ball is a small, hollow rubber ball used in the sport of squash.