Lemon shark vision: the science and the numbers
Negaprion brevirostris · order Carcharhiniformes · Sharks and rays: all the numbers
The lemon shark has one cone type, so no colour vision in daylight.[1] Its eyes cover about 308° with 10° seen by both eyes.[10] The lemon shark stops seeing flicker at 37 Hz, against 60 Hz for people.[27]
- 1colour receptor classMeasured*
- 308°field of viewMeasured
- 37hertz flicker fusion (motion)Measured
The lemon shark (Negaprion brevirostris) is a shark or ray in the order Carcharhiniformes. Its eyes belong to the vision type Shark, ray and warm-eyed ocean predator: few cone types and a reflective layer for dim water. Measured in this species: colour, field of view and motion (flicker fusion). Measured colour or sharpness: a measured receptor set or acuity in this species; other dials come from relatives or group defaults.
This is a simulation built from published eye measurements, not what the animal experiences.
What the lemon shark sees: colour receptors
What stands out
- It has one receptor class for colour, so it sees brightness but no hue.
- Its eyes cover about 308° around the head, with 10° seen by both eyes at once.
- It stops seeing flicker at 37 Hz, against 60 Hz for people in this dataset, so fast motion looks choppier to it.[27][28]
The six dials
Evidence levels: how the tiers work. "Measured" means a value measured in this species; "Estimated" values come from a close relative or an eye-size formula. The last column gives the values for people from the same catalogue.
| Dial | Value | Evidence | Sources | People |
|---|---|---|---|---|
| Colour | Colour receptors 1 receptor class: 518 nm (MWS (green)) species-v1.csv value measured in this species (not in tidy tables) | Measured (not re-verified) | [1] | Colour receptors: 3 receptor classes: 421.5 nm (VS/SWS (violet)), 532 nm (MWS (green)), 558.4 nm (LWS (long)) Measured (not re-verified)[2][3][4][5] |
| Sharpness | Acuity 6.458 cycles per degree median of 6 relatives in family Carcharhinidae: Carcharhinus amblyrhynchos, Carcharhinus leucas, Carcharhinus melanopterus, Carcharhinus plumbeus, Galeocerdo cuvier, Prionace glauca | Estimated | [6][7] | Acuity: 63.75 cycles per degree Measured[8][9] |
| Field of view | Binocular overlap 10° measured in this species (extension 2026-10, fov-verified.csv) | Measured | [10] | Binocular overlap: 122.5° Measured[11][12] Total field of view: 200° Measured (not re-verified)[13] Blind area behind the head: 160° Derived[13] Eye placement: frontal Derived[11][12] |
| Total field of view 308° measured in this species (extension 2026-10, fov-verified.csv) | Measured | [10] | ||
| Field of one eye 159°; horizontal or vertical plane as stated; anaesthetised animals; in water; horizontal plane; mean ± s.e.m. (s.e.m. 0.5) | Measured | [10] | ||
| Binocular overlap (published value) 10°; horizontal or vertical plane as stated; anaesthetised animals; in water; horizontal plane, anterior binocular overlap, physiological (ERG); mean ± s.e.m. (s.e.m. 1.5) | Measured | [10] | ||
| Total field (published value) 308°; horizontal or vertical plane as stated; anaesthetised animals; in water; horizontal plane; mean ± s.e.m. (s.e.m. 0.7) | Measured | [10] | ||
| Field of one eye, vertical plane 184.8°; horizontal or vertical plane as stated; anaesthetised animals; in water; vertical plane; mean ± s.e.m. (s.e.m. 0.4) | Measured | [10] | ||
| Binocular overlap, vertical plane 4.3°; horizontal or vertical plane as stated; anaesthetised animals; in water; vertical plane (dorsal and ventral overlap); mean ± s.e.m. (s.e.m. 0.6) | Measured | [10] | ||
| Total field, vertical plane 360°; horizontal or vertical plane as stated; anaesthetised animals; in water; vertical plane; mean ± s.e.m. (s.e.m. 0.0) | Measured | [10] | ||
| Sharp zones (foveas) | No value in the catalogue. | Number of foveas: 1 Measured[14] Fovea type: fovea Measured[14] | ||
| Night vision | Night sensitivity (optical, against people): estimated F-number S = 0.9 µm² sr, 0.968 times people (log10 ratio -0.014) estimated F-number: receptor size measured in this species, F-number from a group constant or the Matthiessen ratio (not measured in this species) | Derived | [15] | Activity pattern: diurnal Measured (not re-verified)[16][17][18][2][19][20][21][22] Pupil shape: vertical Group default[23][24] Reflective layer (tapetum): no Measured[25] Rods vs cones: cone-dominated Derived[16][17][18][2][19][20][21][22] Night sensitivity (optical, against people): S = 0.93 µm² sr, 1 times people (log10 ratio 0) Derived[26] |
| Motion (flicker fusion) | Flicker fusion frequency 37 Hz median of 1 rows (no bright-light flag) (behavioural/whole-eye ERG rows; all rows: [37.0]) | Measured | [27] | Flicker fusion frequency: 60 Hz Measured[27][28] |
All sharks and rays side by side: Sharks and rays: every measurement. Method: how we know what animals see.
Sources
- Hart et al. 2025
- Longcore 2023
- Kirwan
- Müller et al. 2009
- Thermal Activation and Photoactivation of Visual… 2004
- Caves et al. 2023
- Claes et al. 2014
- Kirk et al. 2004
- Veilleux et al. 2014
- McComb et al. 2009
- Heesy 2004
- Heffner et al. 1992
- Campbell & Green 1965
- Kopania et al. 2025
- Claes et al. 2014
- Anderson et al. 2017
- Borges et al. 2018
- Wilman et al. 2014
- Maor et al. 2017
- Jones et al. 2009
- Schmitz et al. 2011
- Moura et al. 2024
- Banks et al. 2015
- Cervino et al. 2021
- Guareschi et al. 2025
- Brauburger et al. 2026
- Healy et al. 2013
- Inger et al. 2014
Every value cites its sources (all sources). Values were extracted from these works and converted (units, medians, derived values); changes are ours, and the listed sources do not endorse this site. Data: catalogue-v1, built 2026-09-29. Accuracy notes: how accurate is this? Method: how we know.