Studies on the Uteri and Ovaries in Fur Seals : I. Macroscopical Observation with Special Reference to the Multiparaous Changes

オットセイ雌生殖器の研究 : I 経産にともなう変化の肉眼的観察

Okamoto Toshikazu

広島大学水畜産学部紀要

Journal of the Faculty of Fisheries and Animal Husbandry, Hiroshima University

オットセイの卵巣の黄体とその退縮過程,子宮の経産にともなう変化を肉眼的に観察した.材料は,1967年1月から5月に水産庁東海区水産研究所が捕獲したオットセイ,1～10才の29個体のものである.

オットセイの卵巣は肉眼的に妊娠性黄体,その陳旧物と思われる白体および白斑が区別される.

白体は,1個体に最大4個しか見られないので,分娩後4年以内に消失と考えられる.さらに非妊娠性黄体の存在を考慮に入れると,白体の存否による妊娠歴の判定は誤まりを生ずる可能性がある.

子宮角の太さ,表面に見られる溝および割面に見られる脈管層の変化と同側卵巣の白体数との関係から,子宮角に経産による何らかの変化があると考える.

Gross analyses of the ovaries and uterine horns from 29 female fur seals, collected in western Pacific Ocean, off northern Japan from January to May, were done to clarify the macroscopically visible changes of the ovaries and uterine horns in pregnancy and after parturition.
1. The corpora lutea of pregnancy, corpora albicantia and white scars in the ovaries were macroscopically distinguished.
2. The judgement of the parturition experience by the presence of corpora albicantia may not be always correct, because the corpora albicantia and the white scars seemed to disappear within four years after parturition and the corpora lutea of nonpregnancy exists.
3. The results of the present study on the appearance of corpora lutea and corpora albicantia supported the view that most female fur seals matured sexually at three or four years old.
4. From the relation between the number of the corpora albicantia and the structures of the uterine horn, it was presummed that the multiparous changes could be expressed by the macroscopically visible changes of the uterine horns of fur seals.

Zoology [ 480 ]

eng

広島大学水畜産学部

[ISSN] 0440-8756

[NCID] AN00213563

[NAID] 40018463932