Figure 40.14: A School of Darkness-Preferring Fish Finds Dark Patches Faster as the Number of Fish in the School Increases Juvenile golden shiners (Notemigonus) prefer areas in the water where the light intensity is low. Schools were placed in an aquarium where dark areas were present but moved from place to place. (A) Three successive images of a school, taken 2 seconds apart, as the school finds and enters a dark patch. (B) An index of a school’s effectiveness in finding dark patches. The index is plotted against the number of fish in the school. Vertical bars are 95% confidence intervals (see Appendix B).