Ecological implications of fecal pellet size, production and consumption by copepods

The volume of fecal pellets produced by the calanoid copepods Temora turbinata and Eucalanus pileatus increases with increasing weight of the copepod. Pellets produced by nauplii of E. pileatus are eaten by adult females of the same species at about the same rates as phytoplankton which has a volume similar to that of the pellets (10/sup 3/ ..mu..m/sup 3/). Pellet production rates of juveniles change little with increasing body weight. By comparing two copepod populations it is concluded that the size distribution of feeding copepods determines the percentage of fecal matter produced which reaches the sea floor.