A Note on the Clutch Size and Shape of Egg Sacs of Hynobius boulengeri from the Sobo-Katamuki Mountains, Kyushu, Japan (Urodela: Hynobiidae)

Abstract

We report the clutch size and egg sac morphology of Hynobius boulengeri from the Sobo-Katamuki Mountains, Kyushu. A total of 11 clutches (mean clutch size=39.2), each in a pair of egg sacs, were found in a steep, rocky stream head at about 900 m asl. on 6 May 2000 and 5 May 2001. The morphology of the egg sac was unique, having a string-like shape without a distinct whiptail structure at the free end. The clutch size and egg sac shape of H. boulengeri were most similar to those of H. stejnegeri, which occurs parapatrically with H. boulengeri in Kyushu.