ISSN:
1432-1351
Keywords:
Stomatopod
;
Vision
;
Crustacean
;
Optics
;
Sensitivity
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Anatomical dimensions of individual ommatidia from various regions in the eyes of six species of stomatopod have been measured. Using these measurements, estimates of the sensitivity and acceptance angle of each ommatidium were calculated. The relationship between sensitivity distribution in various eye regions and habitat was examined. There is a good correlation between the sensitivity of eyes in the six species examined and their habitat or activity cycle. Animals living in deeper or more turbid water, or which are often active at night possess eyes with relatively high sensitivity. Ommatidia in six-row mid-bands are more sensitive than those in surrounding eye regions. This is achieved by enlarging ommatidial size or decreasing focal length. Increased light capture is necessary in these rows as they contain dense intrarhabdomal filters and tiered rhabdoms which drastically attenuate light as it passes down the rhabdom. Acute zone facets are larger, also for additional sensitivity. The way the image is sampled was studied by comparing acceptance angles to inter-ommatidial angles, measured previously. In most eye regions of most eyes these angles are matched. Where this is not the case (in the mid-band, near mid-band regions and the edge of the eye) an explanation can be found in the function of the region involved, or that of the closely adjacent regions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00197766
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