Phelsuma grandis is a diurnal arboreal species of day gecko. These geckos are part of the Phelsuma group, which consists of in excess of 70 species and subspecies. They are commonly referred to as the Madagascar giant day gecko, due to their large size. They are native to areas of tropical and subtropical forest in northern Madagascar, but have been introduced to several other subtropical locations outside their range. P. grandis feeds on various invertebrates, very small vertebrates, and nectars. It is bred and sold as an exotic pet. Taxonomy Its generic name is a Latinized version of the last name of Dutch physician Murk van Phelsum. Its specific name grandis is Latin for "great". The species Phelsuma grandis described by Gray 1870 was elevated from subspecies status (P. madagascariensis grandis) by Raxworthy et al. in 2007, after environmental niche modeling revealed significant and reliable differences between it and other members of the P. madagascariensis-clade. This elevation has since received further molecular support. P. grandis possesses also the junior synonyms Phelsuma madagascariensis venusta Mertens, 1964 and Phelsuma madagascariensis notissima Mertens, 1970 (fide Meier, 1982). The common name, appended to the current accepted name, has been given as Madagascar giant day gecko or variants such as Giant Day Gecko. Description This lizard reaches a total length of 9-11″ (23-28cm), with females generally being smaller than males. The body colour is bright green or, rarely, bluish green. A red stripe extends from the nostril to the eye. On the back there are typically red coloured dots or bars. These red markings are quite variable, and in some cases, completely absent, though the line extending from the nostril to the eye is always present. Some specimens may have small blue spots. Adult specimens may have large sacs on their necks. These are stored calcium sacks. Young individuals of the species often exhibit much more red than their parents, but as time passes, many of the markings fade, to leave those that will stay for the remainder of the gecko's life. The underside of these animals is a creamy white ranging to an eggy yellow. When stressed, the colouration darkens, rendering the whole animal a dark green, and the red markings on the face and back more orange in hue. Distribution and habitat This species is widely distributed in northern and northwest Madagascar. There are a few recorded populations of this species also in