Spatial mapping influences navigation in Entomacrodus striatus

ABSTRACT We tested the orientation capabilities during jumping in blackspotted rockskippers (Entomacrodus striatus). Amphibious fish routinely navigate between terrestrial and aquatic habitats and use either spatial mapping or visual cues to determine where to safely jump. We recorded jumping direction during three experiments: training, visual cue disruption, and spatial memory disruption. During the first round of training, the fish were able to jump to safety in a novel environment, regardless of starting orientation (p < 0.001). E. striatus were able to learn the terrain after repeated conditioning and continued to jump in the same direction after we moved rocks to the opposite side of the table (visual cue disruption), even if that meant jumping into a wall (p = 0.033). To test memory disruption, we injected the fish with NOS inhibitor L-NAME and found fish jumps became randomly distributed (p = 0.452). These results suggest blackspotted rockskippers entrain using visual cues and then rely on a mental map for subsequent jumps.