|On the usefulness of digestive enzyme activity as index for feeding activity in copepods|
Oosterhuis, S.S.; Baars, M.A. (1985). On the usefulness of digestive enzyme activity as index for feeding activity in copepods. Hydrobiol. Bull. 19(1): 89-100
In: Hydrobiological Bulletin. Netherlands Hydrobiological Society: Amsterdam. ISSN 0165-1404, more
Enzymatic activity; Food intake; Food intake; Grazing; Ingestion; Measurement; Copepoda [WoRMS]; Temora longicornis (Müller O.F., 1785) [WoRMS]; Marine
|Authors|| || Top |
- Oosterhuis, S.S.
- Baars, M.A.
Digestive enzyme activities (amylase, trypsin and laminarinase) of copepods were compared with the diurnal pattern of gut fluorescence. In most cases gut fluorescence, representing feeding activity, was highest at night but enzyme activity, representing enzyme concentration, more often than not followed a different pattern or did not change noticeably. In starvation experiments it was noted that in the first hours after transfer to filtered water, sudden increases of decreases in enzyme concentration in copepods occurred, after which it often returned to previous levels. It is concluded that the relation between synthesis of enzyme and loss by egestion is variable, and that enzyme concentration is not a good index for enzyme turnover rate. Short-term variations in feeding activity are therefore not uniformly reflected in changes of enzyme concentration. Long-term acclimation of enzyme activity was studied in adult females of Temora longicornis reared at the laboratory at different temperatures and food levels (with food dominated by the heterotrophic dinoflagellate Oxyrrhis ).