Document Detail

Interaction between photoperiod and an endogenous seasonal factor in influencing the diel locomotor activity of the benthic polychaete Nereis virens Sars.
MedLine Citation:
PMID:  15111365     Owner:  NLM     Status:  MEDLINE    
The locomotor activity of Nereis virens Sars associated with food prospecting was investigated in response to photoperiod and season using an actograph. Experimental animals which had been reared under natural photoperiods were exposed to two constant photoperiodic treatments, LD 16:8 and LD 8:16, in both the autumn and winter and in the absence of tidal entrainment. Autocorrelation analysis of rhythmicity showed that during the autumn, animals under the LD 16:8 photoperiod displayed a strong nocturnal rhythm of activity, whereas animals under the LD 8:16 photoperiod showed only a weak nocturnal activity rhythm. This is believed to represent an autumn feeding cessation that is triggered when the animals pass through a critical photoperiod LD(crit) <12:>12. Later in the winter, however, animals exposed to both photoperiodic treatments showed strong rhythms of foraging activity irrespective of the imposed photoperiod. It is suggested that the autumn cessation may maximize the fitness of N. virens, a spring-breeding semelparous organism, by reducing risk during gamete maturation, while spontaneous resurgence of activity after the winter solstice permits animals that are not physiologically competent to spawn to accrue further metabolic reserves. This response is believed to be initiated by a seasonal (possibly circannual) endogenous oscillator or interval timer.
Kim S Last; Peter J W Olive
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Biological bulletin     Volume:  206     ISSN:  0006-3185     ISO Abbreviation:  Biol. Bull.     Publication Date:  2004 Apr 
Date Detail:
Created Date:  2004-04-27     Completed Date:  2004-06-28     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2984727R     Medline TA:  Biol Bull     Country:  United States    
Other Details:
Languages:  eng     Pagination:  103-12     Citation Subset:  IM    
School of Marine Sciences and Technology, Ridley Building, University of Newcastle upon Tyne, NE1 7RU, United Kingdom.
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MeSH Terms
Circadian Rhythm / physiology*
Feeding Behavior*
Locomotion / physiology*
Polychaeta / physiology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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