Crocodiles don't focus underwater
Article
- Accepted:
- 9 Citations
- 130 Downloads
Summary
Crocodilians are amphibious reptiles which hunt prey both on land and in water. Previous refractive and anatomical studies have suggested that their eyes can focus objects in air and that their ability to refocus the eye underwater may be limited. Examination of the plane of focus of six species of crocodilians both in air and underwater has revealed that they are generally well focused in air for distant targets and severely defocused underwater. These results suggest that sensory systems other than vision must play an important role in prey capture underwater.
Abbreviation
- D
diopter
Preview
Unable to display preview. Download preview PDF.
References
- Beer T (1898) Die Akkommodation des Auges bei den Reptilien. Pflügers Arch 69:507Google Scholar
- Fleishman L, Rand AS (in press)Caiman crocodilus does not require vision for underwater prey capture. J HerpetolGoogle Scholar
- Howland HC, Howland B (1974) Photorefraction: a technique for study of refractive state at a distance. J Opt Soc Am 64:240–249Google Scholar
- Howland HC, Sayles N (1985) Photokeratometric and photorefractive measurements of astigmatism in infants and young children. Vision Res 25:73Google Scholar
- Howland HC, Sivak J (1984) Penguin vision in air and water. Vision Res 24:1905–1909Google Scholar
- Michaels DD (1985) Visual optics and refraction, 3rd edn. Mosby, St. LouisGoogle Scholar
- Murphy CJ, Howland HC (1983) Owl eyes: Accommodation, corneal curvature and refractive state. J Comp Physiol 151:277–284Google Scholar
- Neill WT (1971) Last of the ruling reptiles. Columbia University Press, New YorkGoogle Scholar
- Schaller GB, Crawshaw PG Jr (1982) Fishing behavior of the Paraguayan caiman (Caiman crocodilus). Copeia 1982:66–72Google Scholar
- Sivak JG (1980) Avian mechanisms for vision in air and water. Trends NeuroSci 1980:314–317Google Scholar
- Underwood G (1970) The eye. In: Gans C (ed) Biology of the Reptilia, vol 2. Academic Press, New York, pp 1–79Google Scholar
- Walls GL (1967) The vertebrate eye and its adaptive radiation. Hafner, New YorkGoogle Scholar
Copyright information
© Springer-Verlag 1988