The Reproductive Cycle of the Brown Anole ( Anolis sagrei ), an Introduced Lizard Species in Taiwan

Abstract

During two collection periods, of 13 and 15 months respectively, seven hundred and forty-three brown anoles ( Anolis sagrei ) were collected from Santzepu, Sheishan District, Chiayi County (23°25’51’’ N 120°28’30’’ E). The lizards were measured and dissected to determine the reproductive cycle of this invasive species in Taiwan. The smallest female showing sexual maturity had a snout-vent length of 34 mm, while that of the smallest male was 30 mm. Reproduction was seasonal, and ovigerous females were maximal from April to September and declined to zero in January, while in the males, the mean testis mass and volume was maximal from April to June, and minimal from October to December. The majority of the males collected in the period from February to August were in a stage of spermiogenesis, while from September to January spermatogenesis appeared to be minimal. Males with spermatozoa, which could mate, were present throughout both study periods. This study demonstrated that the reproductive cycle of the Anolis sagrei population in Taiwan is long and cyclic, and that it is very similar to that of conspecific populations in Belize, Cuba, Florida, and Hawaii. In view of the potential for A. sagrei taking over new territories, drastic steps are merited to prevent future introductions of this species.