Fig. 4

Fig. 4

Effects of Bifidobacterium longum subsp. longum BL21 on reproductive behaviors and hormonal responses in zebrafish. (A) Diagram of the experimental tank setup, divided into a starting zone ('1') and a chasing zone ('2') to assess zebrafish mating behaviors. (B) Table presenting the frequency of male zebrafish chasing behaviors per minute across four groups: Control (CTL), Cyclophosphamide-only (CS), treated with BL21 (BL21), and a Clomiphene Citrate positive control (CC). (C) Movement trajectory plots for male (blue) and female (pink) zebrafish in the CS group showing baseline activities. (D) Enhanced trajectories in the BL21 group illustrate more frequent and interactive chasing, indicating improved reproductive behaviors after treatment. (E) Testosterone levels graph comparing responses across all groups, highlighting hormonal adjustments following treatments. (F) Follicle-stimulating hormone (FSH) levels graph, demonstrating gonadotropic responses to the treatments. (G) Luteinizing hormone (LH) levels graph, detailing endocrine responses across the treatment groups. * p < 0.05, ** p < 0.01, *** p < 0.001.