This lemur is known from littoral forests in southeastern Madagascar. The 2020 IUCN assessment lists forest fragments from the dry forest at Petriky to the wetter forest at Ste Luce.
The 1894 handbook account under Opolemur thomasi reports a gray back washed with rusty brown and silvery hair tips. The crown was darker; a white band ran from between the eyes to the bare nose pad, and the white neck ring was broken by a gray patch.
The 2020 IUCN assessment describes littoral-forest populations as mainly frugivorous, living in pairs, and hibernating for several months between May and October. It notes that the ecological studies it cites treated this taxon as C. medius.
An extinction-risk assessment has not been added yet.