The effect of laboratory conditions on the extrapolation of experimental measurements to the ecology of marine zooplankton VI. Changes in physiological activities and biochemical components of Acetes sibogae australis and Acartia australis after capture

An investigation was made into the possible causes for the decline of physiological activities in Acetes sibogae australis Colefax and Acartia australis Farran during their maintenance for a period of 2 d following capture. Physiological activities comprising respiration, electron transport system (ETS) activity and excretion of ammonia and phosphate, and the biochemical components protein, RNA, ATP and adenylate energy charge (EC) were measured. Excluding fluctuation in the ammonia excretion rate, physiological rates and biochemical components decreased on an individual basis with time after capture for both species for this period. These decreases were generally moderated if expressed on a protein basis. Notwithstanding these changes, the adenylate EC of both species was constant at the normal level. From the results of stable EC and other physiological and biochemical consequences, it was concluded that food shortage rather than capture stress was the major factor contributing to decreases in the various physiological and biochemical properties of the two zooplankton species studied.