タマキビおよびクロタマキビの繁殖

概要

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In 1956, the writer observed the breeding of Littorivaga brevicula (Philippi) at Asamushi, Aomori Prefecture, and Littorivaga atkana (Dall), in 1957, at Hakodate, Hokkaido, Japan. 1. Littorivaga brevicula (Philippi) liberated planktonic eggs with a transparent, colourless and helmet-shaped capsule. The capsule measures about 350μ in diameter, about 170μ in height, and the egg about 84μ in diameter. The larva hatches about eight days after the spawning at 10℃ through the concave spot at the center of the bottom of the capsule. The breeding continued from February to April while the snails were still living in the area from high to low tide. Nearly matured eggs and spermatozoa were found in the gonads of the snails exceeding 6.5mm in shell height. 2. Littorivaga atkana (Dall) liberated and deposited eggs in an ootheca under or at sides of stones near mean tide. The egg was contained in a transparent, colourless and egg-shaped capsule, in which it was covered by a semi-transparent substance. The capsule measures about 550μ in diameter, about 400μ in height, and the egg about 200μ in diameter. An ootheca includes about 120 egg-capsules, and several oothecas gather to form large masses. The breeding continued from January to February on the rocky coast of Hakodate.
日本貝類学会の論文
1958-02-28