Morphological Variation and Sexual Dimorphism in Gekko japonicus from Fukuoka, Northern Kyushu, Japan

Abstract

The external morphology of 121 geckos collected on buildings in Fukuoka City was examined. All of them were identified as Gekko japonicus by the following characteristics. They had enlarged tubercles on the back, the neck, the forearm, and the crus. They had 2-5 (average, 2.9) cloacal spurs on each side of a tail. Adult males had 3-8 preanal pores. Forty-five percent of the specimens had caudal tubercles. More females had caudal tubercles than males. Males, with one exception, and females with SVL<53mm lacked swollen endo- lymphatic sacs. Of females with SVL>53mm, 58.5% had swollen endolymphatic sacs. SVL of adult females older than one year old was larger than that of adult males older than one year. Sexual dimorphism in head length relative to SVL was small (male/female ratio= 1.013).