Boldness in Zebrafish Larvae—Development and Differences between a Domesticated Lab Strain and Offspring of Wild-Caught Fish

Zebrafish (Danio rerio) are becoming one of the most important model organisms in behavioural neuroscience. It has been shown repeatedly that different zebrafish strains show large differences. These divergent profiles may have a genetic basis, but environmental factors and previous experience also known to greatly affect phenotype zebrafish. could be expected differences at larval stage should less affected by experience. In present study, we screened larvae AB strain offspring wild-caught for boldness, using an open field test. order follow development, studied age 5-, 7-, 12- 30-days post fertilization (dpf). Behaviour, as well clearly differed between strains. Wild showed larger total distance moved than larvae, both light dark conditions. were already 12 dpf became more pronounced with age. had greater variance compared variables. We previously bold shy adult differ brain expression dopamine opioid receptors. The results current study wild display significantly higher drd2b 30 dpf, difference related activity. did not detect any