ISSN:
1573-5117
Keywords:
diapause
;
feeding
;
functional response
;
digestive enzymes
;
cyclopoids
;
zooplankton
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Three different methods were used to compare the feeding patterns of active cyclopoids and cyclopoids in active diapause from different habitats. First, we offered 14C- labeled algal detritus to stage III, stage IV (two different physiological groups), and adult females of Acanthocyclops vernalis from temporary water-bodies of the Volga Delta. Second, we compared the functional responses of active and actively diapausing cyclopoids preying on copepod nauplii. Stage III, stage IV (various physiological groups), stage V, adult males and females of Acanthocyclops viridis, Cyclops kolensis, C. abyssorum sevani from the Volga Delta, Lake Sevan (Armenia), and Mozhaisk Reservoir (Moscow District) were tested. Finally, we examined the activity of digestive enzymes (proteases) of CIV of C. kolensis from Mozhaisk Reservoir at different temperatures and temperature acclimation regimes. All three approaches used have led to similar conclusions. Actively diapausing cyclopoids were capable of feeding on both plant and animal prey; however, their feeding rates and digestive enzyme activity were 2–8 times lower than those of active cyclopoids of similar size. At the initial stage of active diapause the feeding rates were comparable with those of active cyclopoids then declined to a low level during approximately two weeks. Transfer of cyclopoids undergoing winter diapause from ambient temperature (4 °C) to warmer water (20 °C) resulted in dramatic increase of proteases activity only if the acclimation period was relatively long (two weeks).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00016806
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