Fish Fun - Population Simulation

In an attempt to start down the path of web development, I started by using Processing to build a little project. Based on an old Linux screensaver, I built a processing version of the concept. I still can't find the original screensaver, but here are a number of applets with various rules.

The basic rules of the simulator are that there a fish of different colors (13 in all the simulations you will see). There are big fish and little fish of the same color. All fish need to move every timestep to survive. Big fish have attributes for how long they live for, when they can breed, and how many little fish they need to eat. Little fish have attributes for how long until they become a big fish. By adjusting these parameters we can watch a number of emergent behaviours, and it's fun to watch.

Click on the applets below to see various population simulations. Note that these simulations have only been tested in Chrome and Firefox on PCs. Also, these are intense simulations and will hog your processor.

Basic Usage

To use the simulator, click on the links in the next section to load the Java applet. If you have Java enabled, eventually, the screen will load up and you can click on the green button to start the simulation. The blue button turns a magnifying glass that you can move around the screen to see the fish in more detail. The histogram box shows the percent population of each type of fish currently alive in the simulation.

Here is a picture of the basic layout of the simulation. The magnifying glass is on and the three boxes are displayed on the bottom of the image.


Links to Initial Simulations

  • In this simulation, the fish can only breed with big fish of another color (by coming in contact with one another), and a big fish eating a small fish (of the opposite color) results in quicker breeding age and longer life. Normal Life
  • This simulation is similar to the previous except there is a significantly lower number of a starting fish popuation. It's a small world after all
  • In this simulation, the fish are allowed to breed with their own kind. This causes a steady state relatively quickly. Keep to your own
  • In this simulation, the fish live, grow, and breed quickly. Fast and the Furious


Pretty Simulations



Pretty Sounds

  • Turn on the magnifying glass to hear the fish and their mournful song. I hear them . Suggestion by Lindsay Grace though he wanted more an emergent noise behaviour


Super Fish



The Future For the Fish

Depending on time and external demand, I might make the next versions so you can manually experiment with the parameters and rules.