mollusc eye
{{Short description|Visual organs of the phylum}}
The molluscs have the widest variety of eye morphologies of any phylum,{{cite journal | first1 = J. M.| first2 = D. J.| last2 = Eernisse| title = Charting Evolution's Trajectory: Using Molluscan Eye Diversity to Understand Parallel and Convergent Evolution | last1 = Serb | journal = Evolution: Education and Outreach | volume = 1 | issue = 4| pages = 439–447 | year = 2008 | doi = 10.1007/s12052-008-0084-1 | doi-access = free}} and a large degree of variation in their function. Cephalopods such as octopus, squid, and cuttlefish have eyes as complex as those of vertebrates, while scallops have up to 100 simple eyes.{{cite journal |last1=Land |first1=M F |last2=Fernald |first2=R D |title=The Evolution of Eyes |journal=Annual Review of Neuroscience |date=March 1992 |volume=15 |issue=1 |pages=1–29 |doi=10.1146/annurev.ne.15.030192.000245 |pmid=1575438 }}
Diversity
There are between seven and eleven distinct eye types in molluscs.[http://www.mapoflife.org/topics/topic_282_Camera-eyes-in-gastropod-molluscs/ 'Camera eyes in gastropod molluscs"], mapoflife.org Molluscs have eyes of all levels of complexity, from the pit eyes of many gastropods, to the pinhole eyes of the Nautilus, to the lensed eyes of the other cephalopods. Compound eyes are present in some bivalves, and reflective 'mirrors' have been innovated by other lineages such as scallops. As well as varying in complexity, the eyes of molluscs span a huge range in size; they may be from {{convert|20|µm|in|abbr=on|sigfig=1}} to {{convert|27|cm|in|abbr=on}} across.
Anatomy
Gastropods and cephalopods have paired eyes on their heads (and sometimes tails), 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. Chitons have a dispersed network of tiny eyes over the surface of their shells which may act together as a compound eye.
Many gastropods have stalked eyes; the eye can be retracted into the stalk itself in the presence of danger.
{{expand section|content for subsevtions below|date=March 2025}}
=Cephalopod eyes=
{{main|Cephalopod eye}}
=Nautilus eyes=
=Gastropod eyes=
=Bivalve eyes=
=Chiton eyes=
See also
References
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