Individual behavioral variation reflects personality divergence in the upcoming model organism Nothobranchius furzeri

Abstract

In the animal kingdom, behavioral variation among individuals has often been reported. However, stable among-individual differences along a behavioral continuum-reflective of personality variation-have only recently become a key target of research. While a vast body of descriptive literature exists on animal personality, hypothesis-driven quantitative studies are largely deficient. One of the main constraints to advance the field is the lack of suitable model organisms. Here, we explore whether N. furzeri could be a valuable model to bridge descriptive and hypothesis-driven research to further unravel the causes, function and evolution of animal personality. As a first step toward this end, we perform a common garden laboratory experiment to examine if behavioral variation in the turquoise killifish Nothobranchius furzeri reflects personality divergence. Furthermore, we explore if multiple behavioral traits are correlated. We deliver "proof of principle" of personality variation among N. furzeri individuals in multiple behavioral traits. Because of the vast body of available genomic and physiological information, the well-characterized ecological background and an exceptionally short life cycle, N. furzeri is an excellent model organism to further elucidate the causes and implications of behavioral variation in an eco-evolutionary context.

Keywords: Nothobranchius; animal personality; behavioral ecology; behavioral variation; repeatability.

Figure 1

Schematic representation of the different test arenas used (top view). All tanks are LxWxH 49 × 19 × 16 cm and hold 9 L of water, except for the open field arena which only holds water to a height of 2 cm (approx. 1.9 L of water). (a) Experimental setup for the emergence test. The start compartment resembles the housing conditions. A doorway (diameter 20 mm) allows individuals to explore the novel, larger part of the tank which holds artificial plants as shelter in the furthest half of the compartment. (b) Open field experimental setup. (c) Experimental setup for the habitat choice test. The tank is equally divided in an open part and a part provided with artificial plants as shelter. The dotted line represents a virtual barrier. (d) Experimental setup for the life skills test, used to characterize feeding and antipredator behavior. The experimental compartment was virtually divided in four equally sized zones (delineated by the dotted lines). Zone 2 holds an artificial plant as shelter, whereas both feeding stimulus and simulated avian attack were applied in zone 3

Figure 2

Spearman rank correlation coefficients (in bold) per pair of behavioral traits. p‐values (false discovery rate controlled) are shown in italics. Significant correlation coefficients are depicted in color (red for negative correlation, blue for positive correlation). Emergence time: latency time to enter novel environment (emergence test), Distance: total distance moved (open field test), Frequency: number of times the fish entered centrum (open field test), Duration: cumulative duration in centrum (open field test), Habitat choice: habitat preference (habitat choice test), Latency feeding 1: latency time to feed before attack (life skills test), Latency feeding 2: latency time to resume feeding (life skills test), TTM: time till movement after attack (life skills test)