Interpopulation Variations in Clutch Size and Egg Size in the Japanese Salamander, Hynobius nigrescens : Ecology

概要

論文の詳細を見る
Interpopulation variations in egg size and clutch size in Hynobius nigrescens were studied in 32 populations from various breeding ponds in the Niigata area. As the altitude increased, the date of oviposition was delayed. However, the dates of oviposition in low elevation populations were varied independent of the altitude. The average number of eggs in an egg sac ranged from 19.5 to 70.2, and the average egg diameter ranged from 2.17 to 2.92mm among the populations. Number and size of eggs among the populations were varied clinally. As the altitude increased, or as the date of oviposition was delayed, the average number of eggs decreased. The average egg size increased with the altitude. However, the egg size decreased with the delay in the date of oviposition among 16 lowland populations. The average total egg volume decreased with the delay in the date of oviposition. Among montane populations, however, the total egg volume showed a tendency to increase with the altitude. From the results of multiple regression analyses, the variations in the number of eggs and total egg volume were explained by the variations in the altitude and the date of oviposition. It was conceivable that the altitude and the date of oviposition were factors of the variations independent of each other. On the other hand, the variation in egg size was explained by the variations in the altitude, latitude and population size.
社団法人日本動物学会の論文
1988-10-15