Robert Mertens's day gecko (Phelsuma robertmertensi) is diurnal species of lizard in the family Gekkonidae. The species is endemic to the Comoros.
Etymology
The specific name, robertmertensi, is in honour of German herpetologist Robert Mertens. The body colour can be dark green or bluish green. An orange mid dorsal stripe extends from the head to the tail. The sides of the neck as well as the flanks are greyish brown.
Geographic range
Phelsuma robertmertensi inhabits only a small area on the island of Mayotte in the Comoro Islands.