Figure 10. KTW functional response.

Gj is the grazing rate upon prey species j (mmol m⁻³ d⁻¹); Q^j_switching gives the fraction of prey species j in the predators' diet (n.d.); Q_feeding gives the overall feeding probability of predators (n.d.); V_max gives the maximum ingestion rate (mmol m⁻³ d⁻¹); g_max is the maximum specific rate for ingestion (d⁻¹); k_sat is the half-saturation constant for ingestion (mmol m⁻³); Z is the concentration of predators (mmol m⁻³); Pj is the concentration of prey species j (mmol m⁻³); ρj is a constant prey preference (n.d.); β is the Hill coefficient that measures how the feeding rate varies with total prey density no dimensions (n.d.); and α is the KTW coefficient that gives the potential for selective predation: when α=1.0 there is no switching (for example, passive filter feeding); when α>1.0 there is prey switching (that is, active selective predation).