photo-, phot-, -photic

(Greek: light; ultraviolet and infrared radiation; radiant energy)

topophototaxis
The directed movement or orientation of a motile organism towards the source of a light stimulus.

Etymologically related "light, shine, glow" word families: ethero-; fulg-; luco-; lumen-, lum-; luna, luni-; lustr-; phengo-; pheno-; phospho-; scinti-, scintill-; splendo-.