Temporal patterns and sex differences in dyadic interactions in a wild zebrafish population

Area of Science:

• Ethology
• Behavioral Ecology
• Ichthyology

Background:

• Male-female interactions are dynamic and crucial for reproductive success in group-living organisms.
• Zebrafish (Danio rerio) are widely used model organisms, but their wild mating ecology remains understudied.
• Understanding behavioral dimorphism is key to interpreting social interactions in fish.

Purpose of the Study:

• To investigate diel (24-hour) temporal patterns in inter-sex dyadic interactions in wild zebrafish.
• To identify the occurrence of behavioral dimorphism in zebrafish interactive behaviors.
• To explore the influence of time of day and oviposition substrate on zebrafish mating behaviors.

Main Methods:

• Observation of randomly paired wild zebrafish (male and female).
• Data collection on six discrete inter-individual interactive behaviors (mating, aggression, display) at three time intervals (early morning, morning, afternoon).
• Generalized linear mixed models used to analyze behavioral traits, considering time, sex, and substrate presence.

Main Results:

• Mating-associated behaviors were most frequent in the early morning and declined throughout the day.
• The presence of gravel substrate for egg-laying significantly influenced mating-associated behaviors.
• This study provides the first detailed account of behavioral dimorphism between sexes in wild zebrafish.

Conclusions:

• Wild zebrafish display distinct diel patterns in mating behaviors, with a preference for morning activity.
• Oviposition substrate availability is a critical factor influencing zebrafish reproductive interactions.
• Findings offer insights into the complex social dynamics of zebrafish and inform experimental design for behavioral and toxicological studies.