Adaptive features of aquatic mammals' eye

  title={Adaptive features of aquatic mammals' eye},
  author={Alla M. Mass and Alexander Ya. Supin},
  journal={The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology},
  • A. M. Mass, A. Supin
  • Published 1 June 2007
  • Environmental Science
  • The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology
The eye of aquatic mammals demonstrates several adaptations to both underwater and aerial vision. This study offers a review of eye anatomy in four groups of aquatic animals: cetaceans (toothed and baleen whales), pinnipeds (seals, sea lions, and walruses), sirenians (manatees and dugongs), and sea otters. Eye anatomy and optics, retinal laminar morphology, and topography of ganglion cell distribution are discussed with particular reference to aquatic specializations for underwater versus… 
Anatomical adaptations of aquatic mammals
The articles in this issue are a blend of literature review and new, hypothesis‐driven anatomical research, which highlight the special nature of anatomical form and function in aquatic mammals that enables their exquisite adaptation for life in such a challenging environment.
Eye Optics in Semiaquatic Mammals for Aerial and Aquatic Vision
Based on anatomical measurements of refractive structures in the eye, the positions of focused images were computed for several groups of semiaquatic mammals: rodents, a nonpinniped semiaquatic
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.
Morphology of the eyeball from the humpback whale (Megaptera novaeangliae)
The Humpback whale eyeball is similar to other cetaceans and suggests an adaptation to diving and migration, contributing to the perception of differences in temperature, pressure, and lighting.
Eye Histology and Ganglion Cell Topography of Northern Elephant Seals (Mirounga angustirostris)
Anatomical and histological traits of the eye that may improve light sensitivity in northern elephant seals are described, consistent with the predicted evolutionary adaptations to the photic environment of the bathypelagic zone.
Morphology of the Eye of the Southern Right Whales (Eubalaena australis)
The aim of this study was to describe the eye anatomy of the southern right whale (Eubalaena australis), and it was found that the eyes of the calves differed from those of the adults in having less periorbital fat surrounding the eyeball.
The eyes of the deep diving hooded seal (Cystophora cristata) enhance sensitivity to ultraviolet light
It is shown that the pelagic hooded seal (Cystophora cristata) has a highly UV permissive cornea and lens, and is likely to be more UV sensitive than the results imply.
Sensory biology of aquatic mammals
This special issue on the ‘‘Sensory biology of aquatic mammals’’ presents reviews and original studies on most major taxa that have been studied so far, and covers the pinnipeds, the cetaceans and the sirenians (dugong and manatees).
Microscopic anatomy of ocular globe in diurnal desert rodent Psammomys obesus (Cretzschmar, 1828)
The ocular globe of sand rat demonstrates a high degree of development and several specific features associated with adaptation to life style and arid environment.
A comparative analysis of cone photoreceptor morphology in bowhead and beluga whales
Two proteins involved in magnetosensation were present in these cone structures suggesting the possibility for an alternative functional role in responding to changes in geomagnetic fields, and provide prefatory evidence of potential functional reassignment of these cells.


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.
A comparative study of the anatomy of the iris and ciliary body in aquatic mammals
The results indicate that in completely aquatic mammals the ciliary muscle is rudimentary, and in fact, appears to be lacking in one species (beluga whale), while the c auxiliary muscle seems to be better developed in the amphibious pinnipeds (California sea lion, elephant seal, and walrus).
Corneal anatomy of marine mammals
The corneal anatomy of fin whales, minke whales, harp seals, ringed seals, and bearded seals was examined to determine if marine mammals have evolved specialized corneas for life in a marine habitat.
For whales and seals the ocean is not blue: a visual pigment loss in marine mammals*
The S‐cone loss in marine species from two distant mammalian orders strongly argues for convergent evolution and an adaptive advantage of that trait in the marine visual environment, suggesting that the S‐cones may have been lost in all whales and seals.
Anatomy of the eye of the sperm whale ( Physeter macrocephalus L.)
Eyes of sperm whales were investigated macro- and microscopically to suggest that the anatomy of the sclera, ophthalmic rete and retractor muscle is linked to the ability of cetaceans to protrude and retract their eyes.
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.
Microscopic anatomy of the eye of the deep‐diving Antarctic Weddell seal (Leptonychotes weddellii)
The combination of a well‐developed tapetum lucidum, an unpigmented pigment epithelium, well‐ developed rods, and a high number of rods converging on only few ganglion cells is obviously an adaptation to an extreme light sensitivity, enabling the animals to make use of the little light available in the deep sea.
Distribution of Ganglion Cells and Object Localizing Ability in the Retina of Three Cetaceans
The distribution of gan glion cells in the retina of three small cetaceans (a false killer whale, a pacific white-sided dolphin and a beluga) are examined, and the visual function of localizing objects in cetACE is discussed.
The 12 Tursiops eyes were consistent for vascular structure, optic papillae, dimensional components and tapetal coloration and there was a difference between species in the short wavelength regions of the spectrum.