IPA: //ˌfoʊtəˈnɛɡətɪv//
KK: /ˈfoʊtəˌnɛɡətɪv/
Describing something that is repelled by light or shows a negative response to light.
The photonegative behavior of the organism makes it avoid bright areas.
Photonegative → It is formed from "photo-" (from Greek "phōs", meaning light) and "negative" (from Latin "negativus", meaning denying or refusing). The word refers to an image that is a reversal of light and dark, hence denying the original light values.
Think of 'light' ('photo-') being 'denied' ('negative') to remember that a photonegative is an image where the light and dark areas are reversed.
No commonly confused words.