Reproductive stage affects the daily behavioral patterns of parthenogenetic marbled crayfish

Behavioral patterns are complex physiological and ethological phenomena usually synchronized with the day-night cycle. Reproduction is an important modulator of these activities in crayfish females with differences between non-reproductive (NR) and egg-carrying (EC) individuals. However, the behavioral pattern of maturing females with forming glair glands (GG) has never been assessed. Hence, we compared the behavioral patterns of NR, EC, and GG females of marbled crayfish Procambarus virginalis, observing their behavior in an empty arena and in the presence of critical resources—shelter and food. Crayfish were video-recorded for 24 hours and their activity, distance moved, and velocity analyzed. The results indicated distinct behavioral patterns linked to reproductive stages and resource availability. Specifically, NR females displayed higher activity levels than EC and GG females, which spent most of their time in the shelter. On the other hand, the presence of food increased the overall activity of GG compared to EC females and reduced shelter usage, highlighting a trade-off between foraging and safety. These findings demonstrated an interaction between the reproductive stage and resource acquisition behavior, providing insights into crayfish adaptive strategies and, in the context of invasive crayfish, potential impacts on ecosystem dynamics. This study highlights the importance of accounting for the reproductive stage and timing in experiments involving marbled crayfish or other crayfish species.