concholepas are photopositive
and geo-negative (Manriquez unpublished data), but during larval development their behavioral traits are largely unknown.
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).
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.
Taking advantage of both organisms' photopositive
nature, water and airflow were turned off and the system was left to sit for 15 min.
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 > 0.05; Fig.
saltator responds to UV light by photopositive
behavior: UV light attracted about 70% of the experimental animals.