food availability; that is, they do not eat more than growth and metabolism
require.
4 The maximum ration is obtained at lower concentrations of large cells
than of small cells.Fig. 7.4 Effect of cell concentration on ingestion rate (I, cells eaten copepod−1 h−1,
left) and water-clearance rate, (F, ml copepod−1 h−1, right) in Calanus pacificus
females feeding on small-, medium- and large-sized, centric diatoms. All three
ingestion asymptotes are at ∼1.1 μg cell carbon h−1.
(^) (After Frost 1972.)