Ref ID : 3072
Sudzuki Minoru; [Studies on the Egg-Carring Types in Rotifera I. Genus Pompholyx]. Zoological Magazine (Dobutsugaku Zasshi) 64(7):219-224, 1955
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Most of the planktonic rotifers carry themselves their eggs adhering to the posterior part of their body, and, in certain genera, even the egg-shells from which the young have already hatched out. Examining 54 species of rotifers under 31 genera from a marsh and a reservoir in Urawa during these four years, the present writer has been able to distinguish various characteristic types of egg-carrying. In this paper is dealt with a type represented by Pompholyx sulcata, whose egg is attached to the female body by a thread-like structure, conveniently called here Gosse's thread. This species has special glands (Stieldrusen: Leissling,'24) at the mastax-brain region. Wesenberg-Lund ('23,'30) and Remane ('33) considered them as foot-glands which are commonly found in both male and female rotifers and serve the animal for adhering to the substratum. According to the writer's consideration, the glands are not identical with the so-called foot-glands judging from their developmental and anatomical features; on the other hand the glands observed by the writer for the first time on both sides of the cloacal opening seem to be foot-glands which are hardly related to the formation of the Gosse's thread. The style glands seem to secrete the Gosse's thread mentioned above. They consist apparently of two portions, the anterior and the posterior. As the egg-formation nears completion, the style glands seem to secrete muscus-like substance into the folded sheath (Hohlcanal: Remane '33) which opens at the hindmost part of the body, where the sticky substance meets with the egg and becomes stiffened to the Gosse's threads as time passes on. The thread is 60-80 µm in length and 1 µm diameter. By the ventral retractors associated with the glands, the threads may be retracted through the cloacal opening into the sheath.