Age determination and growth by skeletochronology of Rana holtzi, an endemic frog from Turkey

We applied skeletochronology on phalanges to assess the individual age and growth patterns of a breeding population portion of Rana holtzi, an endemic frog from Turkey. Snout-vent length (SVL) ranged from 46.4 to 66.8mm for males and 39.2 to 66mm for females. Ages ranged from 4 to 6 years for males, and from 4 to 7 for females. Neither SVL nor age differed between the sexes. Both males and females showed high variability of growth patterns during ontogeny. The high frequency of double LAG (lines of arrested growth), observed mainly in the males, suggests that the frogs of our sample experienced frequent but not periodic growth arrests. We stress the practical value of skeletochronology for population survey on this interesting endemism which is at great risk of decline due to human causes.