茨城県筑波山系におけるハコネサンショウウオOnychodactylus japonicus(HOUTTUYN)の水中生活期の生態
1982 年 32 巻 3 号 p. 395-403
詳細
1982 年 32 巻 3 号 p. 395-403
HAYASE, Nagatoshi (Yamato Junior High School, Ibaraki) & YAMANE, Soichi (Biol. Lab., Fac. Ed., Ibaraki Univ., Ibaraki). 1982. Life history during the aquatic life period of a salamander, Onychodactylus japonicus (HOUTTUYN), at Mts. Tsukuba, Ibaraki, Japan. Jap. J. Ecol., 32 : 395-403. The duration of the aquatic life period (including incubation and larval stages) of Onychodactylus japonicus is estimated to be 3 years and 2 to 5 months, based on analyses of age group structures and morphological and ecological observations. Eggs are supposed to be laid at head waters between early and late May and hatch between August and October. Hatchlings seem to stay there for several months, then migrate downstream and begin to feed. They land on in the fourth summer, after metamorphosis into subadults (terrestrial form) when the body length (including tail) has reached about 8 cm. Survival rate during the aquatic life period, except just after hatching is nearly constant at about 50% per year.
