PASHEMOS: a versatile program written in Pascal to simulate patterns on the shells of molluscs, according to the Meinhardt model

Abstract

In this paper we describe PASHEMOS, a user-friendly program written in Pascal to solve the Meinhardt-Klingler model numerically. This model studies the shell pattern pigmentation of molluscs. Moreover, PASHEMOS enables theoretical analysis to be performed on the different steady states. The program takes into account the four differential equation systems established in the model. It numerically solves these systems. This program is developed in such a way that both the equation system type and the parameter values can be chosen. The pattern is displayed in each case, and other output possibilities are available (i.e. three-dimensional concentration plotting, phase plane, phase space, stability analysis). The implementation of the program for the case of a three-variable system is shown as an example of PASHEMOS handling. Program applications for other models are also discussed.