Meeting Abstract
Larval fish improve in their ability to forage in the dark as they grow, but it is unclear whether this is due to heightened prey sensing. Therefore, we performed experiments that recorded larval zebrafish (Danio rerio) as they fed on Artemia nauplii in the dark during the first month of growth. We found that larvae failed to forage when the lateral line system was compromised. However, we did not find that the morphology of the lateral line changed appreciably over growth. We therefore tested whether larvae improve in detecting prey by learning to use the lateral line system by raising groups of larvae that were prohibited from learning. One group was raised on dead Artemia, which offered the same nutritional content as live prey, but did not produce a hydrodynamic stimulus. The lateral line system was ablated daily in another group of larvae fed live Artemia. Both groups were grown for one month and were consequently naïve to flow stimuli generated by prey. After a month of growth, treated larvae were permitted to recover the lateral line and feeding experiments were conducted in the dark. We found that the capture probability of both groups was significantly lower than the control, but were indistinguishable from larvae that did not have a functioning lateral line system. This suggests that larval zebrafish learn to use the lateral line system to capture mobile prey, which permits them to forage in the dark. This ability to learn demonstrates that zebrafish larvae have flexibility in their ability to specialize to particular prey during early development.
