Microspectrophotometric evidence for cone monochromacy in sharks

  title={Microspectrophotometric evidence for cone monochromacy in sharks},
  author={Nathan S. Hart and Susan Theiss and Blake K. Harahush and Shaun P. Collin},
Sharks are apex predators, and their evolutionary success is in part due to an impressive array of sensory systems, including vision. The eyes of sharks are well developed and function over a wide range of light levels. However, whilst close relatives of the sharks—the rays and chimaeras—are known to have the potential for colour vision, an evolutionary trait thought to provide distinct survival advantages, evidence for colour vision in sharks remains equivocal. Using single-receptor… 

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.

Cone monochromacy and visual pigment spectral tuning in wobbegong sharks

In this study, the visual opsin genes of two wobbegong species were isolated to verify the molecular basis of their monochromacy and provide further evidence to support the concept that sharks possess only a single cone type.

Visual and electrosensory ecology of batoid elasmobranchs

The results support the potential for color vision in cownose rays and yellow stingrays and future investigations should reveal the extent to which color discrimination is significant in a behavioral context.

Vision in elasmobranchs and their relatives: 21st century advances.

This review identifies a number of exciting new developments in the understanding of vision in cartilaginous fishes that have been made since the turn of the century. These include the results of

Photoreceptor types, visual pigments, and topographic specializations in the retinas of hydrophiid sea snakes

The retinal photoreceptors of spine‐bellied and horned sea snakes have three types of visual pigment sensitive to short, medium, and long wavelengths of light, and both species possess a cone‐like double photoreceptor subtype, both the principal and accessory member of which contain the LWS visual pigment.

Fluorescence characterisation and visual ecology of pseudocheilinid wrasses

Combining the emission characteristics of fluorescence body colouration and the spectral sensitivity data of retinal cells suggests that the visual system of C. solorensis is sensitive to pseudocheilinid fluorescence.

Behavioural evidence for colour vision in an elasmobranch

This study presents the first behavioural evidence for colour vision in any elasmobranch, using a paradigm that incorporates extensive controls for relative stimulus brightness, and shows that these rays are capable of discriminating coloured reward stimuli from other coloured (unrewarded) distracter stimuli of variable brightness.

Vision in sharks and rays: Opsin diversity and colour vision.

  • N. Hart
  • Environmental Science, Biology
    Seminars in cell & developmental biology
  • 2020

Visual pigments in a palaeognath bird, the emu Dromaius novaehollandiae: implications for spectral sensitivity and the origin of ultraviolet vision

Results show that the emu resembles most other bird species in possessing four spectrally distinct single cones, as well as double cones and rods, and suggests that UVS is the most likely ancestral state for birds.

Spectral Tuning in the Eyes of Deep-Sea Lanternfishes (Myctophidae): A Novel Sexually Dimorphic Intra-Ocular Filter

It is suggested that this unique specialisation of yellow pigmentation in Lanternfishes acts as a filter to enhance contrast, thereby improving the detection of bioluminescent emissions and possibly fluorescence in the extreme environment of the deep sea.



Multiple cone visual pigments and the potential for trichromatic colour vision in two species of elasmobranch

The finding raises the possibility that some species are able to discriminate colour – a visual ability traditionally thought to be lacking in this vertebrate class – and it is evident that the visual ecology of elasmobranchs is far more complex than once thought.

Colour vision and visual ecology of the blue-spotted maskray, Dasyatis kuhlii Müller & Henle, 1814

Measurement of the spectral absorption of the rod and cone visual pigments of the blue-spotted maskray, Dasyatis kuhlii, using microspectrophotometry reveals that wavelengths below 380 nm do not reach the retina, indicating that D. kuhLii is relatively insensitive to ultraviolet radiation.

Photoreceptors and visual pigments of Black Sea elasmobranchs

Literature data on the Cyclostomes and results obtained for Elasmobranchs indicate that the photopic vision is phylogenetically more ancient than the scotopic system.

The ecology of cone pigments in teleost fishes

Vision in the peafowl (Aves: Pavo cristatus).

  • N. Hart
  • Biology
    The Journal of experimental biology
  • 2002
The visual sense of the Indian blue-shouldered peafowl Pavo cristatus was investigated with respect to the spectral absorption characteristics of the retinal photoreceptors, the spectral

Investigation of fish vision by means of S-potential. III. Photoreceptors and spectral sensitivity in elasmobranchs' retinae.

From these observations the ability to discriminate color is thought to exist in the Dasyatis whereas the sharks in all probability are color blind.

Visual pigments and the photic environment: The cottoid fish of Lake Baikal

In search of the visual pigment template

Absorbance spectra were recorded by microspectrophotometry from 39 different rod and cone types representing amphibians, reptiles, and fishes, with A1- or A2-based visual pigments and λmax ranging

Visual pigments and photoreceptors in two species of shark, Triakis semifasciata and Mustelus henlei

The retinal photoreceptors of brown smoothhound sharks and leopard sharks were studied by spectrophotometry analysis of visual pigment extracts, microspectrophotometric examination of single cells, and scanning electron microscopy to support the idea that brown smoothhounds are either more nocturnal than leopard shark or are active at greater depths.

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.