Weak expression of reproductive seasonality in a dwarf gecko ( Lygodactylus verticillatus) from arid south–western Madagascar

Abstract

The reproductive cycle of Lygodactylus verticillatus, a small diurnal lizard of the family Gekkonidae, was studied using a large preserved sample from Lake Ihotry in a very arid and seasonal environment in Madagascar. Ovigerous females and small juveniles were found in all seasons. In males, no significant seasonal differences in testis size were found. However, the percentage of ovigerous females was distinctly lower in the dry, cool season (April–October). This indicates reproductive activity in L. verticillatus during the whole year, with a rather weakly marked seasonality that results in lower incidence of reproduction during the dry season. Most females dissected had two eggs or follicles of similar size in their oviducts, and only in 5% of the specimens did one oviduct contain a mature egg or a follicle of distinctly larger size than the other oviduct. A clutch size of two eggs therefore seems to prevail in this species, despite its small size (the range of adult female snout-vent lengths was 20–27 mm). According to the available literature data, continuous or weakly seasonal reproduction seems to be more common in geckos than in other lizards, which might be related to the constraint of their low clutch size (1–2 eggs).