Gut fluorescent content of dominant copepods was measured according to the method described by Mackas and Bohrer (1976; doi:10.1016/0022-0981(76)90077-0) and modified by Morales et al. (Estimates of ingestion in copepod assemblages: gut fluorescence in relation to body size. In: Trophic Relationships in the Marine Environment. Proceedings of the 24th European Marine Biology Symposium, pp. 565-577. Edited by M. Barnes, and R.N. Gibson. Aberdeen University1990). Deep-frozen samples of mesozooplankton were used for measurements of gut fluorescence of copepods. Gut evacuation rate was calculated according to Dam and Peterson (1988; doi:10.1016/0022-0981(88)90105-0). Ingestion rates were estimated by applying gut clearance rate to gut pigment contents. Turner Fluorimeter was used for measurements of copepod gut fluorescence.