Note
Larvae of many shallow-water marine invertebrates show phototactic behaviors which may allow them to exercise some control over their positions in the water column. Such behavior should be useful only in regions where light provides a consistent directional cue and might not, therefore, be expected in species found exclusively in deep water where light levels are extremely low. In this paper, we investigated larval phototactic responses in two barnacle and one prosobranch gastropod species that occur epifaunally on tropical, bathyal sea urchins.