Young postlarvae display
photopositive behavior in the laboratory, while older postlarvae appear to be photonegative (Hadley, 1905; Botero and Atema, 1982).
1981); however,
photopositive larvae may swim toward the surface during full moons, avoiding predator filled reefs (Thresher 1984).
Taking advantage of both organisms'
photopositive nature, water and airflow were turned off and the system was left to sit for 15 min.
Light traps are taxon-selective because they target fishes that are
photopositive and able to swim to and enter the trap (Thorrold, 1992; Choat et al.
Three-week-old larvae were observed to be strongly
photopositive, but the ontogeny of phototaxis was not observed over the full course of larval development, so we are not sure if its onset was associated with the development of accessory eyes.
For example, at relatively high current velocities, settlement-stage larvae that are
photopositive but that have limited swimming speeds may not have the ability to respond to a light cue and swim into a light trap as they are carried past the sampling device.
The mean percentage of photonegative and
photopositive cer cariae at each light intensity was not significantly different from the control (P > 0.
saltator responds to UV light by
photopositive behavior: UV light attracted about 70% of the experimental animals.
