How does the bottlenose dolphin see?

The bottlenose dolphin (Tursiops truncatus) is a mammal in the order Cetacea. Its eyes belong to the vision type Marine mammal cone monochromat: 1 cone class (no S cone): no hue at all, rod-dominated, blue-shifted.

Measured in this species: colour, sharpness, foveas and night vision. Measured core: measured values on at least 3 of the 6 dials. Every value below carries its evidence level and sources; nothing is typed by hand.

Sample scene drawn in code: a face with red lips, a green shirt, red and green apples, flowers and a colour strip, as a person sees it. — The sample scene as a person sees it.

The same sample scene rendered by the See Like Animals engine for the bottlenose dolphin's eyes, using the values in the table below. — The same scene rendered for the bottlenose dolphin (60° field of view, daylight).

See your photo as the bottlenose dolphinThis species is part of the full catalogue in the tool (full unlock). Your photo stays on your device.

What stands out

It has one receptor class for colour, so it sees brightness but no hue.
Its sharpest vision resolves 3.4 cycles per degree: the finest stripe pattern it can tell apart from grey.
Both eyes see the same 75° in front of it (binocular overlap), where depth is judged best.
It stops seeing flicker at 60 Hz, against 60 Hz for people in this dataset, so fast motion looks about the same.^[18][19]
Activity pattern: cathemeral.

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.

Vision values for the bottlenose dolphin (Tursiops truncatus), catalogue-v1
Dial	Value	Evidence	Sources
Colour	Colour receptors 1 receptor class: 524 nm (MWS (green)) measured in this species	Measured	^[1]
Sharpness	Acuity 3.4 cycles per degree median of 2 behavioural rows (method priority rule); acuity_cpd: in-air rows (aquatic animal: in-water rows used) set aside (labelled alternative: 2.05)	Measured (not re-verified)	^[2][3]
Field of view	Binocular overlap 75° median of 41 relatives in class Mammalia: Octodon degus, Octodon lunatus, Equus caballus, Ovis aries, Bos taurus, Capra hircus	Group default	^[4][5][6][7]
Field of view	Eye placement frontal	Group default	^[4][5][6][7]
Sharp zones (foveas)	Number of foveas 0 fovea_present / area_centralis_type (retinal topography; count 1 = fovea present, 0 = none)	Measured	^[8]
Sharp zones (foveas)	Fovea type area centralis, horizontal streak	Measured	^[8]
Night vision	Activity pattern cathemeral tie ['cathemeral', 'diurnal'] broken by species-level studies (round-3 tie-break rule 2) (of 5 rows): aquatic; arrhythmic/cathemeral; diurnal; mesopic	Measured (not re-verified)	^{[9][10][11][12][13]}
	Pupil shape vertical	Group default	^[14][15]
	Reflective layer (tapetum) yes	Measured (not re-verified)	^[16]
	Rods vs cones mixed nocturnal -> rod-dominated; crepuscular / cathemeral / mixed -> mixed; diurnal -> cone-dominated	Derived	^{[9][10][11][12][13]}
Motion (flicker fusion)	Flicker fusion frequency 60 Hz median of 21 relatives in class Mammalia: Rattus norvegicus, Cavia porcellus, Mus musculus, Felis catus, Macaca mulatta, Macaca nemestrina	Group default	^{[17][18][19][20]}

Comparisons

Bottlenose dolphin vs harbour seal

Related animals

California sea lion same vision type
Harbour seal same vision type
Northern elephant seal same vision type
Pacific walrus same vision type
Harp seal same vision type
Northern fur seal same vision type

More mammals: all mammals with measured vision data.

Sources

Frazer SA, Baghalian M, et al. 2024. Discovering genotype-phenotype relationships with machine learning and the Visual Physiology Opsin Database (VPOD). GigaScience 13:giae073; VPOD v1.3 data release. doi.org/10.5281/zenodo.19051998
Caves EM, Fernandez-Juricic E, Kelley LA (2024) Ecological and morphological correlates of visual acuity in birds. J Exp Biol 227(2): jeb246063. Supplementary Table S1.. doi.org/10.1242/jeb.246063
Kirk EC, Kay RF 2004. The evolution of high visual acuity in the Anthropoidea. In Anthropoid Origins, Table 1 (behavioural acuity). doi.org/10.1007/978-1-4419-8873-7_20
Heesy CP 2004. On the relationship between orbit orientation and binocular visual field overlap in mammals. Anat Rec 281A:1104, Table 1. doi.org/10.1002/ar.a.20116
Heffner RS, Heffner HE 1992. Visual factors in sound localization in mammals. J Comp Neurol 317:219, Table 1 (via Evo-M1 sensory merge). doi.org/10.1002/cne.903170302
Vega-Zuniga T, Medina FS, Fredes F, et al. 2013. Does nocturnality drive binocular vision? Octodontine rodents as a case study. PLoS ONE 8: e84199.. doi.org/10.1371/journal.pone.0084199
Vega-Zuniga T, Medina FS, Marín G, Letelier JC, Palacios AG, Němec P, Schleich CE, Mpodozis J. (2017). Selective binocular vision loss in two subterranean caviomorph rodents: Spalacopus cyanus and Ctenomys talarum. Scientific reports
Kopania EEK, Clark NL. 2025. Mammalian retinal specializations for high acuity vision evolve in response to both foraging strategies and morphological constraints. Evolution Letters 9: qrae072. Supplementary Tables S1-S2.. doi.org/10.1093/evlett/qrae072
Anderson SR, Wiens JJ. 2017. Out of the dark: 350 million years of conservatism and evolution in diel activity patterns in vertebrates. Evolution 71:1944-1959. Dryad doi:10.5061/dryad.fg700. doi.org/10.5061/dryad.fg700
Borges R, Johnson WE, O'Brien SJ, Gomes C, Heesy CP, Antunes A (2018) Adaptive genomic evolution of opsins reveals that early mammals flourished in nocturnal environments. BMC Genomics 19:121
Wilman et al. 2014 EltonTraits 1.0, MamFuncDat.txt. doi.org/10.6084/m9.figshare.3559887.v1
Schmitz L, Motani R. 2011. Science 332:705-708, SOM. doi.org/10.1126/science.1200043
Moura et al. 2024. A phylogeny-informed characterisation of global tetrapod traits addresses data gaps and biases. PLoS Biol 22:e3002658. TetrapodTraits v3.0.1.. doi.org/10.5281/zenodo.22536349
Banks MS, Sprague WW, Schmoll J, Parnell JAQ, Love GD. 2015. Science Advances 1:e1500391. doi.org/10.1126/sciadv.1500391
Cervino NG et al. 2021. A closer look at pupil diversity and evolution in frogs and toads. Proc R Soc B 288:20211402. doi.org/10.6084/m9.figshare.15112050.v1
species_v1:Standard textbook knowledge
Haarlem CS, Hynes C, Jackson AL, Mitchell KJ, O'Connell RG, Healy K. 2026. Pace of ecology drives the tempo of visual perception across the animal kingdom. Nature Ecology & Evolution (doi:10.1038/s41559-026-02994-7). Figshare dataset 10.6084/m9.figshare.30556475. doi.org/10.6084/m9.figshare.30556475
Healy K, McNally L, Ruxton GD, Cooper N, Jackson AL. 2013. Metabolic rate and body size are linked with perception of temporal information. Animal Behaviour 86:685-696. Table 1. doi.org/10.1016/j.anbehav.2013.06.018
Inger R, Bennie J, Davies TW, Gaston KJ. 2014. Potential biological and ecological effects of flickering artificial light. PLoS ONE 9(5): e98631. Table 3. doi.org/10.1371/journal.pone.0098631
Lafitte A, Sordello R, Legrand M, Nicolas V, Obein G, Reyjol Y. 2022. A flashing light may not be that flashy: A systematic review on critical fusion frequencies. PLoS ONE 17(12): e0279718. S10 File (CFF database). doi.org/10.1371/journal.pone.0279718

Every value cites its sources (all sources). Data: catalogue-v1, built 2026-09-29. Accuracy notes: how accurate is this?