Seasonal and diel activity variations in the shrimp Palaeomon adspersus from a brackish, non-tidal area
Hagerman, L.; Østrup, J. (1980). Seasonal and diel activity variations in the shrimp Palaeomon adspersus from a brackish, non-tidal area. Mar. Ecol. Prog. Ser. 2(4): 329-335 In: Marine Ecology Progress Series. Inter-Research: Oldendorf/Luhe. ISSN 0171-8630; e-ISSN 1616-1599, more |   |
| Keywords | Activity patterns
Biological phenomena > Biological rhythms > Circadian rhythms
Palaemon adspersus Rathke, 1836 [WoRMS]
Brackish water |
| Authors | | Top | - Hagerman, L., more
- Østrup, J.
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| Abstract | Seasonal and diel activity rhythms of P. adspersus from a non-tidal area were investigated in the laboratory by means of photocells. P. adspersus is nocturnal, with maximum activity levels in summer and early autumn, and minimum levels in winter and early spring. When the nights are short the activity consists of 1 brief, intense period; it extends to 2-3 periods when the nights are prolonged. The change from 2 to 1 activity periods is very sharp at the end of April. The total length of the active period was 10 h per 24 h throughout the year. Length of active period and subdivision into smaller periods is considered to be regulated by an endogenous mechanism. Seasonal variations in activity levels are correlated to migratory behaviour in the field and to the reproductive cycle. |
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