Natural preference of zebrafish (Danio rerio) for a dark environment

Abstract

The zebrafish (Danio rerio) has been used as a model in neuroscience but knowledge about its behavior is limited. The aim of this study was to determine the preference of this fish species for a dark or light environment. Initially we used a place preference test and in a second experiment we applied an exit latency test. A two-chamber aquarium was used for the preference test. The aquarium consisted of a black chamber and a white chamber. In the first experiment the animal was placed in the aquarium and the time spent in the two compartments was recorded for 10 min. More time was spent in the black compartment (Wilcoxon matched-pairs signed-rank test, T = 7, N 1 = N 2 = 18, P = 0.0001). In the second experiment the animal was placed in the black or white compartment and the time it took to go from the initial compartment to the opposite one was recorded. The test lasted a maximum of 10 min. The results showed that the animal spent more time to go from the black to the white compartment (Mann-Whitney rank sum test, T = 48, N 1 = 9, N 2 = 8, P<0.0230). These data suggest that this fish species has a natural preference for a dark environment and this characteristic can be very useful for the development of new behavioral paradigms for fish.

Zebrafish, a Potential Novel Research Tool for the Analysis and Modeling of Anxiety

“…And indeed, this was exactly what was found in a light dark preference task: zebrafish avoided the dark compartment and preferred a well illuminated compartment of a two compartment shuttle box (Gerlai et al, 2000). However, Serra et al (1999) showed that zebrafish prefer areas of the test environment with a dark background. The difference in the results of these two studies is not easy to explain but may be due to numerous methodological differences.…”

“…The difference in the results of these two studies is not easy to explain but may be due to numerous methodological differences. For example, Serra et al (1999) used a dark background but the compartment was well illuminated. Whereas Gerlai et al (2000) used a dark compartment that was truly dark as it was covered on all sides and the top.…”

Identification of a brain center whose activity discriminates a choice behavior in zebrafish

“…L/D choice behavior is similarly light-driven yet distinct in duration (observable within minutes to tens of minutes), and it has been reported in adult zebrafish (13,(21)(22)(23). After being individually introduced into a L/D choice chamber (light intensity readings of 300 and 160 Lux, respectively, on each side) (Fig.…”

Adult zebrafish as a model organism for behavioural genetics

“…Protocols to measure anxiety tend to assess one of two variables. The first set of protocols record the reaction of adult fish to novel environments, such as the amount of time spent at the edge of a tank [30,49], at the bottom of a novel tank [34,50] or on the dark side of a light/dark tank [28,51]. The second approach analyses locomotory patterns: freezing, long-lasting increases in basal locomotory activity [6,48,49] and tightening of a fish's shoal [52] have all been reported to be reliable measures of anxiety.…”