A new mathematical model and its application to the growth of crustaceans

We propose a new four-parameter function to describe crustacean growth: W = [f(n) - (f(n) - s(n)) . exp (- k . t(k))](1/n) where s and f are, respectively, initial size and upper asympotic size, and n and k are constants. The new model possesses an unfixed value of the inf lexion point according to its parametric values, and therefore has sufficie nt flexibility to depict diverse crustacean growth curves. In order to eval uate the applicability of this new model, some commonly used models, such a s the Spillman, the Logistic, the Gompertz, the Von Bertalanffy, the Hill, the Richards, and the Janoschek equations, are compared to the new one, usi ng 12 sets of observations. Analysis reveals that the new equation yields e xcellent fitting to the sets of observed data, which suggests it is worth b eing considered in the analysis of crustacean growth data.