Search
Presentation Details
| Can’t or Won’t? Investigating the Behavioral Mechanisms of Schooling in Blind Cavefish |
| Britney Sekulovski, Noam Miller. Wilfrid Laurier University, Waterloo, ON, Canada |
Schooling can be advantageous for many reasons, such as predator avoidance and collective foraging, although it is not observed in all fish species. Cave-dwelling populations of the Mexican tetra (Astyanax mexicanus) have lost the behavior, along with their eyes, while enhancing their lateral line system and undergoing other physiological changes. However, schooling persists in the sighted surface-dwelling population of the same species. We compared schooling characteristics of blind and sighted A. mexicanus, zebrafish (Danio rerio), and null models that assume random movement in our featureless tank. We find that blind cavefish not only fail to school but actively avoid each other, while surface fish and zebrafish form tight schools. Additionally, the administration of isotocin, vasotocin, or antagonists of both hormones affected schooling in all three fish and partially reversed the avoidance seen in the blind fish. Avoidance of conspecifics might be advantageous in the cavefish environment, which has extremely scarce food and no predators. Our data suggest that blind cavefish may not have lost the ability to school but the motivation. |