Age and Body Growth of the Tokay Gecko, Gekko gecko (Linnaeus, 1758), Studied by the Skeletochronological Method

Tokay gecko, Gekko gecko (Linnaeus, 1758) is highly exploited in Java for human consumption in China. Using skeletochronology, the age and body growth of Tokay Geckos from local populations in Central Java (18 females, 21 males) and in East Java (19 females, 42 males) were studied for the first time. A total of 100 frozen specimens (37 females, 63 males) were used. Sex was determined by observing the presence (male) or absence of pre-anal pores (female). Snout to vent length (SVL) of the smallest female and male with the line of arrested growth (LAG) was 127.1 and 160.4 mm, respectively. Both males and females reach sexual maturity before one year old with 98.3 mm SVL for females and 111.6 mm SVL for males. Analysis of the LAG counts indicated that the age of individuals that were harvested was ranged 0 – 2 years for females and males, with SVL ranging 110 – 182 mm. Growth rates in SVL are much faster in males as compared to females, as well as increasing of MP (width of bone from the edge of marrow cavity to the periosteal outer margin) inside femur bone. The mean SVL of males was larger than that of females. The Sexual Dimorphism Index (SDI) was calculated as -0.28, indicating a sexual size dimorphism in favor of males.