Mollusc eye
Themolluscshave the widest variety ofeyemorphologies of anyphylum,[1]and a large degree of variation in their function.Cephalopodssuch asoctopus,squid,andcuttlefishhave eyes as complex as those of vertebrates, whilescallopshave up to 100simple eyes.[2]
Diversity
[edit]There are between seven and eleven distinct eye types in molluscs.[3]Molluscs have eyes of all levels of complexity, from the pit eyes of manygastropods,to the pinhole eyes of theNautilus,to the lensed eyes of the othercephalopods.Compound eyes are present in some bivalves, and reflective 'mirrors' have been innovated by other lineages such asscallops.[1]As well as varying in complexity, the eyes of molluscs span a huge range in size; they may be from 20 μm (0.0008 in) to 27 cm (11 in) across.[1]
Anatomy
[edit]Gastropodsandcephalopodshave paired eyes on their heads (and sometimes tails),[1]but many molluscs do not have clear head regions in which to locate the eyes. Consequently, many molluscs may have a multitude of eyes in more unlikely places, such as along the edge of their shell.[1]Chitonshave a dispersed network oftiny eyesover the surface of their shells which may act together as a compound eye.[1] Many gastropods have stalked eyes; the eye can be retracted into the stalk itself in the presence of danger.[1]
See also
[edit]- Arthropod eye
- Parietal eye
- Sensory organs of gastropods
- Simple eye in invertebrates
- Vision in fish
- Visual system
References
[edit]- ^abcdefgSerb, J. M.; Eernisse, D. J. (2008)."Charting Evolution's Trajectory: Using Molluscan Eye Diversity to Understand Parallel and Convergent Evolution".Evolution: Education and Outreach.1(4): 439–447.doi:10.1007/s12052-008-0084-1.
- ^Land, M F; Fernald, R D (March 1992). "The Evolution of Eyes".Annual Review of Neuroscience.15(1): 1–29.doi:10.1146/annurev.ne.15.030192.000245.
- ^'Camera eyes in gastropod molluscs ",mapoflife.org
External links
[edit]
Media related toMollusca eyesat Wikimedia Commons
