Therefore, and since at different food levels b did not differ significantly, a stronger curvature seems to be realistic for their copepod population. McLaren et al. (1969) suggested that thermal acclimation would only affect parameter α. If this is true, the different values of b may point to fundamental physiological differences between different populations of Temora. This is in contrast with the observation of those authors that b is constant within closely related species (see p. 82 in Klein Breteler & Gonzalez (1986)). The stage duration for each model stage (N1–N6 – naupliar stage, C1, C2, C3, C4, C5 – the five copepodid stages) and the generation

time using Bĕlehrádek’s function were obtained in the present work in accordance with the data of D (see

Figure 4 in Klein Breteler & Gonzalez (1986)). Here, the parameter b was taken from Klein Breteler & Gonzalez (1986); in addition, Selleckchem PF2341066 the values of α calculated in this paper vary from 2 to 3.5 and resemble the values of Klein Breteler & Gonzalez (1986). Bĕlehrádek’s function was converted to D = 10a(T − α)b, where the parameters a and b were described as a function of food concentration: α = a1 log Food + b1 and a = a2 log Food + b2 with the correlation coefficient from 0.69 to 0.97 for the naupliar stage (N1–N6) and the copepodid stage (C1–C5). But the correlation coefficient for a and α as a function of food concentration was too low for all copepodid stages separately (C1, C2, C3, C4, learn more C5). This meant that Bĕlehrádek’s function could not be used to define the mean development times for each copepodid stage separately. In view of this, the stage duration D in this work was obtained as a function of food concentration and temperature using the minimum development time Dmin. Dmin is the value for which the development rate is not Progesterone limited by food availability. The common logarithm of Dmin for T. longicornis was related linearly to the common logarithm of temperature: equation(1) logDmin=alogT+b. The values of a, b, and r, the correlation coefficients for developmental stages N1–N6, C1, C2, C3, C4 and C5 are given in Table 1. 96% of the values of Dmin

computed with equation (1) as a function of temperature lie within the range of the parameter Dmin given by Klein Breteler et al. (1982). The regression equations for each of the model stages of T. longicornis at temperatures ranging from 5 to 20°C are shown in Figure 1. The stage duration D of T. longicornis for developmental stages N1–N6, C1, C2, C3, C4 and C5, and for the period from N1 to medium adult was also obtained here. It was found to be very sensitive to changes in temperature and food concentration. Conversion of the data for D after Klein Breteler & Gonzalez 1986– see Figure 4 in this paper) to natural logarithms yielded a linear relationship between time and food concentration. This relationship was described by the equation equation(2) ln(D−Dmin)=aFood+b; hence, D=eaFood+b+Dmin.