phototactic

1 9.1

Moving toward or away from light

adjective
/ˌfoʊtəʊˈtæktɪk/

Specialized

: fototáctico

Positive phototactic behavior in sea turtles is crucial for their navigation towards the ocean on hatching.
positively phototactic
negatively phototactic

Examples

Stage II and III larvae are also positively phototactic several hours before molting; post-molt they become negatively phototactic (Hadley, 1908).

Academic text (1999)
Roaches are negatively phototactic... which means they run from light.

Mimic 2 (2001)
Stage II and III larvae are also positively phototactic several hours before molting; post-molt they become negatively phototactic (Hadley, 1908).

Academic text (1999)
Many insects, such as moths, are phototactic, flying towards bright lights at night.
Some species of plankton exhibit phototactic movements, swimming toward the surface where there is more light.

Surface Forms

phototactic positive

Morphology

phototactic = phototaxis (opaque) = photo + taxis + ic

The adjective is built on the technical noun 'phototaxis', but the specialized biological meaning is not readily predictable from ordinary B1 vocabulary.

Etymology

The word phototactic combines photo- meaning 'light', as in photograph, and -tactic from a Greek word meaning 'arrange' or 'move'. So it describes a living thing that moves toward or away from light.