How they see
How does a clownfish see the world?
Its stripes glow in secret UV
Nestled in its anemone, the clownfish sees the reef in blue-green and, crucially, in ultraviolet. To another clownfish those famous white stripes are not merely white; they blaze with ultraviolet, a private badge that many of the fish's predators simply cannot see. Camouflage and name-tag in one.
See through their eyes
Human ≈ 60 cpd (20/10)
How sharp is a clownfish's vision?
Its eyes resolve about 4 cycles per degree (20/150 (est.)), while a human reaches around 60 cpd (20/10). Its field of view spans about 300°.
How does a clownfish see a human?
Its eyes resolve about 4 cycles per degree against your 60, so a face has to be roughly 15 times closer for it to pick out the detail you do. Your outline and your movement read clearly; your expression does not.
Colour comparison
How each colour shifts when seen through this animal's eyes, using the same colour model as the app. Tones a screen can't emit (such as ultraviolet) are shown as an approximation.
What colours can a clownfish see?
Blue–green colour with a strong ultraviolet channel that reveals hidden facial/stripe patterns.
Photoreceptors
UV-sensitive reef fish (multiple cones incl. UV)
Cone peak sensitivities
- UV386 nm
- M (green)497 nm
- L (green)535 nm
How does a clownfish see in the dark?
Day-active on bright reefs.
How does a clownfish's vision compare to a human's?
A clownfish's detail sits near 20/150 to your 20/20, but it sees ultraviolet you cannot and reads bright reef colours as vividly as it needs to, from within the safety of its stinging host.
What is special about a clownfish's vision?
- UV stripe signalling
- Private UV communication channel
- Reef-bright colour vision
What the research shows
The first detailed picture of anemonefish colour vision came from genes. Mitchell et al. (2021) sequenced the visual opsins of the false clown anemonefish, Amphiprion ocellaris, and predicted the spectral tuning of each, but those predictions were estimates from sequence alone. Direct measurements followed. Mitchell et al. (2024) used microspectrophotometry on the same species and found an ultraviolet single cone peaking near 386 nm and double cones absorbing near 497, 515 and 531–538 nm; the same study found that UV vision improves the fish's colour discrimination. Stieb et al. (2019) measured a close relative, Amphiprion akindynos, at about 400, 498 and 520 nm.
The chart on this page follows the 2024 measurements: 386 nm for the ultraviolet cone and 497 and 535 nm for the two longer classes. Acuity has not been measured in anemonefish; the 4 cpd used here, roughly 20/150, is an estimate for a small reef fish, and the roughly 300-degree field and a flicker-fusion range of 40–70 Hz are estimates too. The central limit of any screen version is the ultraviolet itself. A phone camera blocks UV and a display has no UV primary, so a highlight on the white bars marks where the signal is, not what another anemonefish sees there.
Guides: Animals that see ultraviolet · Which animal has the best eyesight? · All guides
Scientific sources
- Siebeck et al. (2010)
- Mitchell et al. (2024)
- Stieb et al. (2019)
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