The free FishSim Basic provides a collection of tools for creation, animation as well as presentation of 3D virtual fish stimuli in a very user-friendly way:

(1) FishSim: game engine based central operating tool to
visualize 3D fish stimuli and their movements;


(2) FishCreator: tool for easy creation of variable 3D fish stimuli on the basis of a virtual species model which can be varied in length, height and thickness and equipped with different fin and body textures; currently included fish species: sailfin molly (Poecilia latipinna), Atlantic molly (Poecilia mexicana). Additional models are under progress;

(3) FishSteering: tool for sequential animation of any number of prior created 3D fish stimuli using a video game controller. Animation may include general movements (swimming) and specific movements (single fins). Animated sequences are saved as specific video files for the use with FishPlayer;

(4) FishPlayer: tool for easy and standardized presentation of previously created animation sequences on one or two screens.
It includes management of separate animation playlists for each screen and an option for automatic swimming behavior of a 3D fish stimulus. Algorithms for automatic swimming patterns can be adapted to specific needs.

FishSim is based on the robot operation system ROS ( and the game engine Irrlicht ( The open-source nature of FishSim makes it possible to adapt the toolchain to one’s own specific needs. If the user is farmiliar with 3D modeling in Blender (, new species models can be created and added to the toolchain. Specific movement alterations and aspects concerning general animation properties etc. can also be adjusted, provided that the user is familiar with programming (C++) and LINUX.

All software needed to operate or work with FishSim is freely available.

Minimum system requirements for FishSim Basic:

CPU:                            Intel Core i3 or comparable
RAM:                           4 GB
Video Card:                NVIDIA GeForce GTX 460 or
                                    AMD Radeon HD5850 (1 GB VRAM)
Free Disk Space:       30 GB (including installation of Ubuntu)


Software requirements:

  • Computer/laptop with the free LINUX operating system Ubuntu (; it is possible to run Ubuntu alongside Windows

  • FishCreator requires the free 3D creation program Blender ( and a graphics editing program, like the free GIMP ( or Adobe Photoshop (, to create fin and body textures


We are currently working on a future version FishSim Pro which will also include additional fish species and new features for real-time 3D fish tracking, interactive virtual fish stimuli and behavioral data analysis.


Müller K, Smielik I, Hütwohl JM, Gierszewski S, Witte K, Kuhnert KD (2016) The virtual lover: variable and easily guided 3D fish animations as an innovative tool in mate-choice experiments with sailfin mollies - I. Design and implementation. Current Zoology 63 (1): 55-64 .

Gierszewski S, Müller K, Smielik I, Hütwohl JM, Kuhnert KD, Witte K (2016) The virtual lover: variable and easily guided 3D fish animations as an innovative tool in mate-choice experiments with sailfin mollies – II. Validation.  Current Zoology 63 (1): 65-74. DOI:


Watch the Virtual Fish Project at YouTube: 

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