. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 284 T. W. CRONIN _ 100. Figure 6. Results obtained from a female Gonodactylus oerstedii maintained in constant conditions from 22 to 28 January 1988. The animal was kept in a controlled light:dark cycle, indicated by the light and dark bands on the abscissa, prior to the experiment. Stimulation was at 500 nm, at intervals of 20 min, and at a quantal intensity of X 1012 quanta cm'2 s~'. Otherwise as in Figure 1. ure 4, on the order of 10" quanta cm 2 s ', are similar to intensities an animal would experience at a de
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 284 T. W. CRONIN _ 100. Figure 6. Results obtained from a female Gonodactylus oerstedii maintained in constant conditions from 22 to 28 January 1988. The animal was kept in a controlled light:dark cycle, indicated by the light and dark bands on the abscissa, prior to the experiment. Stimulation was at 500 nm, at intervals of 20 min, and at a quantal intensity of X 1012 quanta cm'2 s~'. Otherwise as in Figure 1. ure 4, on the order of 10" quanta cm 2 s ', are similar to intensities an animal would experience at a depth of only a few meters in the coastal waters it inhabits (Forward el 1988). During the daylight phase of the rhythm, such intensities produced no apparent response. If these circadian rhythms are to be properly phased to the diel cycle, they must be entrainable by cycles of light and dark. Animals apparently do entrain completely to a novel light:dark cycle within 12 days, as suggested by the results of the experiment of Figure 4. Presumably, photoreceptors for this entrainment are either within the compound eyes or exist elsewhere in the animal. In fact, many invertebrate species entrain their circadian rhythms using extraocular pathways (see review of Bennett, 1979). In crayfish, and probably other decapod crustaceans, photic entrainment of circadian rhythms can be achieved by retinal illumination (Larimer and Smith, 1980), but such entrainment may also involve photoreceptors of the 6th abdominal ganglion (Fuentes-Pardo and Inclan-Ru- bio, 1987) or other regions of the CNS (Page and Larimer, 1976; Larimer and Smith, 1980). In particular, the work of Page and Larimer (1976) demonstrated that the caudal photoreceptors (in the 6th abdominal ganglion) are not required for entrainment. In contrast to decapod crusta- ceans, S. empusa lacks this caudal photoreceptor (Wilkens and Larimer, 1976), and no other extraretinal photore- ceptors have yet been described in stomatopods.
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
