濟州道産 가무락, Cyclina sinensis의 生殖週期에 關한 組織學的 硏究 = Historical Study on the Reproductive Cycle of the Clam, Cyclina sinensis (Gmelin), in Cheju Island

국문 초록 (Abstract)

濟州道産 가무락, Cyclina sinensis의 生殖巢 構造, 生殖細胞形成過程 및 生殖過期를 光學顯微鏡 및 電子顯微鏡을 使用하여 調査하였다.
1. 生殖巢는 內臟囊의 肝中腸腺 上端에서 足部까지 外側의 大部分을 싸고 있으며 卵巢는 많은 卵巢小囊으로, 精巢 또한 小管狀의 精巢小囊으로 構成되어 있으며 이들 小囊의 內脫上皮가 生殖細胞의 機能을 한다.
2. 生殖巢 外壁은 420∼600㎛로 매우 두꺼우며 上皮層은 30∼40㎛의 單層圓柱상계로 構成되어 있고 이들 上皮層 下方에는 50㎛두께의 結綿纖膠原纖維와 筋纖維가 緻密하게 結合되어 있으며, 下方으로 80㎛두께의 立方形 粘液腺細胞層과 上下層은 從으로, 中層은 橫으로 排列된 結綿纖膠原纖維와 筋纖維가 260∼430㎛의 두꺼운 層으로 되어있다.
3. 未分化間充織과 好酸性顆粒細胞들은 生殖巢 및 生殖細胞형성과 發達에 管養을 供給하는 一種의 管養細胞로 간주된다.
4. 卵母細胞가 70㎛ 前後로 成長하여 卵柄에서 離脫되어 完熟卵의 크기는 90∼120㎛ 前後였다.
5. 卵母細胞의 卵膜과 核膜은 二重膜狀 構造이며, 細胞質內의 卵黃顆粒은 皮質層 內側으로 擴散되며, 脂質顆粒은 核膜 附近에서 出現하여 皮質層으로 分散되었다.
6. 完熟精子의 頭部는 約 5㎛, 尾部는 20㎛ 內外로서 前端의 尖體는 電子密屠가 相異한 두 區域으로 區分되고 尖體와 核 사이에 透明腔이 存在하고 鞭毛의 軸絲構造는 9+2型이며 4個의 球型 mitochondria가 中心體를 둘러싸고 있다.
7. 生殖巢의 發達段階는 分裂增殖期(1∼4月), 成長期(3∼6月). 成熟期(5∼8月), 放出期(7∼9月初), 退化期(9∼12월), 回復期(12∼2月)로 區分할 수 있었다.
8. 産卵期는 水溫이 20℃ 以上으로 上昇하는 7月 初旬부터 9月 初旬으로, 産卵 最盛期는 7月 中旬부터 8月未 사이였다.
9. 雌雄同體는 調査材料 390 個體中 8個體였다.

다국어 초록 (Multilingual Abstract)

The structure of gonad, gametogenesis and the reproductive cycle of the clam, Cyclina sinensis were investigated mainly employing photomicrography and electron micrography.
The materials were sampled monthly at Seongsanpo, Cheju Island from October 1982 to September 1983.
1. The gonad is located between the mid-intestinal gland in the visceral sac and the connective tissue of the foot. The ovary is composed of a number of ovarian sacs. The testis is composed of a number of seminiferous tubules, which form the tubulan structure, and the epithelium of the tubule has the function of germinal epithelium.
2. The outer wall of the gonad is 420-600㎛ thick, and the epithelial layer consists of simple columnar epithelial cells, which are 30-40㎛ thick. Under the epithelial layer are sequentially collagenous fiber layers, mucous gland cells fibromscular capsules compacted by collagenous fibers and muscle fibers. These thicknesses are 50㎛, 80㎛ and 260-430㎛ respectively. The upper and lower fibromuscular capsules are arranged of vertically, and the middle fibromuscular capsules are arranged of longitudinally.
3. Undifferentiated mesenchymal tissue and eosinophilic granular cells function as nutritive cells in the formation and development early stage of germ cells.
4. The oocytes reach approximately 70㎛ in diameter seceded from the yolk stalk, the mature eggs were about 90-120㎛.
5. The plasma membrane the uncleus membrane of oocytes are composed of a double membrane. Accumulation of yolk granules in the cytoplasm begins in the cortical layer and diffusion occurs outside the nuclear envelope and diffuse towards the corticalilayer.
6. The head of the spermatozoa is approximately 5㎛ in length and its tail is about 20㎛. The conical acrosome at the distal part of the head is distinguished by two regions with different electron densities. There is a clear space between the acrosome and nucleus. The flagellum of the tail consits of nine pairs of microtubules at the periphery, on e pair at the center fiber, and four spherical mitochondria form the paranucleus around the centrioles.
7. The development process may be divided into six succesive stages : multiplication (January-April), growing(March-June), mature(May-August), spent(July-eary September), degenerative(September-December) and recovery stages(December-February).
8. Spawnig of C. sinensis occurs from early July ot early September when the sea water temperature was normally above 20℃ and its peak spawing occured from late July ot August.
9. The hermaphroditic were eight individiuals among the 390 individuals examined.