For whales and seals the ocean is not blue: a visual pigment loss in marine mammals*

  title={For whales and seals the ocean is not blue: a visual pigment loss in marine mammals*},
  author={Leo Peichl and G{\"u}nther Behrmann and Ronald H.H. Kr{\"o}ger},
  journal={European Journal of Neuroscience},
Most terrestrial mammals have colour vision based on two spectrally different visual pigments located in two types of retinal cone photoreceptors, i.e. they are cone dichromats with long‐to‐middle‐wave‐sensitive (commonly green) L‐cones and short‐wave‐sensitive (commonly blue) S‐cones. With visual pigment‐specific antibodies, we here demonstrate an absence of S‐cones in the retinae of all whales and seals studied. The sample includes seven species of toothed whales (Odontoceti) and five species… 

Colour vision in aquatic mammals—facts and open questions

The present review summarizes available data on the various aquatic mammalian taxa, assesses the reliability of these data, and discusses the potential adaptive pressures involved in blue cone loss.

Color Vision in Marine Mammals: A Review

Behavioral data indicate that all three groups of marine mammals discussed here (cetaceans, pinnipeds, and manatees) are able to discriminate colors, and a possible underlying mechanism for color vision in pin- nipeds and cetacean could be based on the comparison of rod and cone signals.

Visual opsin diversity in sharks and rays.

The capacity for chromatic vision in elasmobranch fishes is examined and it is inferred that cone monochromacy in sharks has evolved independently on multiple occasions, suggesting that cone-based colour vision may be of little use for large marine predators such as sharks, pinnipeds and cetaceans.

Evolutionary loss of cone photoreception in balaenid whales reveals circuit stability in the mammalian retina

These findings represent the first immunological and anatomical evidence of a naturally occurring rod‐monochromatic mammalian retina, and suggest that despite the loss of cone‐mediated photoreception, the associated cone signaling structures may be maintained for multichannel rod‐based signaling in balaenid whales.

Unusual cone and rod properties in subterranean African mole‐rats (Rodentia, Bathyergidae)

Within rodents an adaptation to subterranean life is compatible with very different spectral cone properties, which contrasts starkly with the situation in the muroid blind mole‐rat Spalax ehrenbergi, which has been reported to possess L‐opin but no S‐opsin.

Genetic evidence for the ancestral loss of short-wavelength-sensitive cone pigments in mysticete and odontocete cetaceans

All modern cetaceans lack functional SWS cone visual pigments and, by extension, the visual capacities that such pigments typically support.

Adaptations for amphibious vision in sea otters (Enhydra lutris): structural and functional observations

The results suggest that sea otters have retained features for low-light vision but rapid adjustments and acute underwater vision may be constrained across varying light levels by a combination of pupil shape, absolute eye size, and the presumed coupling between anterior lens curvature and pupil size during accommodation.

Adaptive features of aquatic mammals' eye

In general, the visual system of marine mammals demonstrates a high degree of development and several specific features associated with adaptation for vision in both the aquatic and aerial environments.

Retinal cone photoreceptor distribution in the American black bear (Ursus americanus)

Examining the subtype and topography of cones in American black bear retinas confirmed that American black bears are predicted to have a dichromatic vision with high acuity indicated by the presence of a dorsotemporally located area centralis.

Retinal Topography in Two Species of Baleen Whale (Cetacea: Mysticeti)

Eye morphology and the topographic distribution of retinal ganglion cells (RGCs) in two species of mysticete, Bryde’s whale and the humpback whale, are investigated, indicating that cetacean eyes are adapted to vision in dim light and adhere to a common “bauplan” that evolved prior to the divergence of the two cetACEan parvorders over 30 million years ago.



Absence of short‐wavelength sensitive cones in the retinae of seals (Carnivora) and African giant rats (Rodentia)

It is concluded that an absence of S‐cones is not exclusively associated with nocturnality, as earless seals are visually active during night and day, and the functional and comparative aspects are discussed.

The visual pigments of the bottlenose dolphin (Tursiops truncatus)

Although the dolphin possesses a gene homologous to other mammalian short-wavelength sensitive (SWS) opsins, it is not expressed in vivo and has accumulated a number of deletions, including a frame-shift mutation at nucleotide position 31, and therefore lacks the common dichromatic form of color vision typical of most terrestrial mammals.

Cone spectral sensitivity in the harbor seal (Phoca vitulina) and implications for color vision

The spectral sensitivities of the cones of harbor seals were measured using a retinal gross potential technique, flicker photometric electroretinography, and found a cone spectral sensitivity curve with a peak at about 510 nm, implying that harbor seals have only a single cone photopigment.

Mutations in S-cone pigment genes and the absence of colour vision in two species of nocturnal primate

Examination of the nucleotide sequences of the S-cone pigment genes reveals that each species has deleterious mutational changes: in comparison to the sequence for the corresponding region of the human gene, exon 4 of the bushbaby S- cone pigment gene has a two nucleotide deletion and a single nucleotide insertion that produces a frame shift and results in the introduction of a stop codon.

Spectral-tuning mechanisms of marine mammal rhodopsins and correlations with foraging depth

The objective of this study was to investigate the molecular basis for changes in the spectral sensitivity of rod visual pigments from seven distantly related marine mammals and show a relationship between blue-shifted rhodopsins, deep-diving foraging behavior, and the substitutions 83Asn and 292Ser.

Mechanism of spectral tuning in the dolphin visual pigments.

The interactions of the three amino acids identified in the rod pigment with the chromophore may be a general mechanism for blue shifting in rod visual pigments and the single substitution in the dolphin LWS opsin gene is a novel mechanism of wavelength modulation in mammalian LWS pigments.

Behavioral Capabilities of Seals and Sea Lions: A Review of Their Hearing, Visual, Learning and Diving Skills

Behavioral capabilities of seals and sea lions (the pinnipeds) are described and summarized in tabular form. Major features of sound detection, pitch perception, sound localization, visual spectral


  • G. H. Jacobs
  • Biology
    Biological reviews of the Cambridge Philosophical Society
  • 1993
This review has evaluated the proposition that relatively few mammalian species have a capacity for colour vision in mammals in the light of recent research on colour vision and its mechanisms in mammals and concluded that the baseline mammalian colour vision is argued to be dichromacy.

Identification of the blue‐sensitive cones in the mammalian retina by anti‐visual pigment antibody

It is demonstrated in two ways that the monoclonal antibody OS‐2 specifically recognized the blue‐sensitive cone cells in the mammalian retina.

Distribution of photoreceptor subtypes in the retina of diurnal and nocturnal primates

  • KC WiklerP. Rakić
  • Biology
    The Journal of neuroscience : the official journal of the Society for Neuroscience
  • 1990
Application of the photoreceptor-class-specific antibodies may provide further insights into the evolution and development of wavelength sensitivity in the retina, as well as enhance the understanding of normal and abnormal color vision in humans.