Virtual fish at the Institute of Biology

„Back to the roots of mate-choice copying“

What is the relevant information to initiate mate-choice copying in the

sailfin molly (Poecilia latipinna)?

The DFG project "Analysis-by-synthesis with virtual fish as a new experimental method in studies on mate choice" deals with the question of which information is critical for fish in order to decide if they copy the mate choice of conspecifics. Mating preferences are often genetically determined. However, recent findings show that non-genetic factors in mate choice can play a role. When living together in groups, social learning can strongly influence the choice of a mating partner. In groups, individuals can observe other conspecifics and gain information about the environment and potential mating partners.

Studies have shown that, under certain conditions, both female and male sailfin mollies (Poecilia latipinna) copy the mate-choice of others, and thus have access to an alternative mate-choice strategy. A sailfin molly female might observe another female in interaction with a male, and from this observation conclude to mate with this male as well. It could be shown that even an observed rejection of a male can lead to the rejection of this male as a potential mating partner in the observing female.

So far, it could not be determined exactly which information is crucial to initiate copying behavior. What are the basic mechanisms of copying behavior? Are there certain behavioral patterns of the individual or certain morphological characteristics that trigger copying? Or does a combination of certain features favor mate-choice copying?

In copying experiments, the information content is changed gradually to shed more light on these underlying questions. Varying the information content is made possible by the use of computer-animated 3D fish models (Figure 1) that have been developed in this interdisciplinary project by the Institute for Real-Time Learning Systems of the University of Siegen.

Live fish

Virtual 3D

wire mesh

3D wire mesh with skin and

virtual skeleton

3D wire mesh with texture of fish body and fins

Figure 1. From live fish to virtual 3D fish models. Using the 3D graphics program Blender (v. 2.70a), virtual 3D male and female fish models were created on the basis of live sailfin mollies.

Computer-animated fish models offer the possibility to change parameters, such as the fin size (see Figure 2), leaving all other factors constant.

This creates highly controlled experimental conditions and allows a more accurate determination of the relevance of the quantity and quality of information provided for mate choice in general and in particular for mate-choice copying, a fascinating alternative mate-choice strategy that is used by sailfin mollies.

Figure 2. FishCreator. In the application FishCreator, a variety of male and female fish models can be created on the basis of size measurements and textures of live sailfin mollies.
Fish models can be adjusted in length/width/height and can further be equipped with various textures for body and fins.

With the help of the software FishSim, that was specifically developed for the interdisciplinary research project "Virtual Fish", different fish models can be created and steered freely with a video game controller. The fish models are then presented in various mate-choice tests with live test fish. With this software it is possible to simulate a copying experiment, in which a live test fish can observe the mate-choice of a virtual conspecific.

Publications

Witte, K., Kniel, N., Kureck, I.M. 2015. Mate-choice copying - Status quo and where to go. Current Zoology. 61(6): 1073-1081.

Nöbel, S. und Witte, K., 2013. Public Information Influences Sperm Transfer to Females in Sailfin Molly Males. PLOS ONE, Vol 8 (1) e53865.

Dubois, F., Drullion, D. & Witte, K., 2012. Social information use may lead to maladaptive decisions: a game theoretic model. Behavioral Ecology, Behavioral Ecology 23 (1): 225-231.

Witte, K. & Nöbel, S., 2011. Learning and mate choice. In: Fish Cognition and Behaviour, 2nd edition, Ed. C. Brown, K. N. Laland & J. Krause, Blackwell Publishing, 81-107.

Witte, K. & Godin, J.-G. J., 2010. Mate choice copying and mate quality bias: are they different processes? A reply to A. Vakirtzis and S. C. Roberts. Behavioral Ecology 21: 193-194.

Witte, K., 2009. Sexuelle Selektion - Die Bedeutung genetischer und sozialer Faktoren für die weibliche Partnerwahl. Praxis der Naturwissenschaften-Bios 3/58, 18-22.

Witte, K. & Klink, K., 2005. No pre-existing bias in sailfin molly females (Poecilia latipinna) for a sword in males. Behaviour 142: 283-303.

Witte, K. & Massmann, R., 2003. Female sailfin mollies, Poecilia latipinna, remember males and copy the choice of others after 1 day. Animal Behaviour 65: 1151-1159.

Witte, K. & Ueding, K., 2003. Sailfin molly females copy the rejection of a male. Behavioral Ecology 14: 389-395.

Witte, K. & Ryan, M. J., 2002. Mate copying in the sailfin molly, Poecilia latipinna, in the wild. Animal Behaviour 63: 943-949.

Witte, K. & Noltemeier, B., 2002. The role of information in mate-choice copying in female sailfin mollies (Poecilia latipinna). Behavioral Ecology and Sociobiology 52: 194-202.

Ueding, K. & Witte, K., 2001. Sailfin molly females copy the rejection of a male. Zoology 104: 38.

Witte, K. & Ryan, M. J., 2000. Mate-choice copying in the wild. Zoology 103: 54.

Witte, K. & Ryan, M. J., 1998. Male body length influences mate-choice copying in the sailfin molly Poecilia latipinna. Behavioral Ecology 9: 534-539.

Witte, K. & Ryan, M. J., 1997. Mate copying in the sailfin molly Poecilia latipinna: the effect of male body size. Adv. Ethol. 32: 201.

More information on the research of the

Institute of Real-Time Learning Systems.

Computer Science