皱纹盘鲍胚后消化系统发育的研究

以组织学、组织化学和透射电镜观察等方法研究了皱纹盘鲍自孵化后的担轮幼虫至1a龄幼鲍10个时期消化系统的胚后发育.食道于面盘幼虫早期出现;自围口壳幼虫食道中段的上皮细胞开始分泌蛋白酶;在上足分化幼体食道侧囊形成;在稚鲍,食道侧囊上皮分化成微绒毛细胞、分泌细胞和纤毛细胞.嗉囊直至稚鲍期才形成;在1a龄幼鲍,嗉囊腔大于胃腔.胃出现于面盘幼虫早期;到匍匐幼虫,胃腔出现单细胞藻.肠出现于面盘幼虫早期;在上足分化幼虫,肠上皮分化为纤毛细胞和微绒毛细胞两种细胞;在稚鲍肠上皮分化成纤毛细胞、微绒毛细胞、Ⅰ型腺细胞、Ⅱ型腺细胞和黏液细胞共5种细胞,肠沟出现.唾液腺形成于上足分化幼虫期.消化腺于面盘幼虫早期出现,自面盘幼虫中期开始分化成嗜碱性细胞和消化细胞.嗜碱性细胞的细胞质由嗜酸性逐渐转变为嗜碱性;至上足分化幼虫,细胞内出现含铁的折光小体.消化细胞自匍匐幼虫摄食起就出现内吞作用,细胞内含大量囊泡.研究表明,发育到稚鲍时,消化系统诸器官的结构和功能已基本接近成鲍.

Developmental study of digestive system of the postembryo disk abalone Haliotis discus hannai Ino

Development of digestive system of postembryo disk abalone Haliotis discus hannai Ino was studied from trochophore larva after hatching to one year old abalone with histological and histochemical methods and electron microscopic observation. Oesophagus appears in early veliger. The epithelial cells of mid oesophagus secrete proteinase in the stage of larva with peritomal. The lateral pouches of mid oesophagus form in the stage of larva with pallial tentacle. In 45 d old juvenile, the epithelium of the lateral pouches differentiates into cells with microvilli, secretory cells and ciliated cells. Crop does not form until 45 d old juvenile, and its lumen is larger than stomach lumen in one year old abalone. Stomach forms in early veliger. In creeping larva, single-cell's algae appear in the lumen of stomach. Intestine also formed in early veliger. The epithelium of intestine differentiates respectively into two and five types of cells in larva with pallial tentacle and 45 d old juvenile. Salivary glands appear in the stage of larva with pallial tentacle. Digestive gland appears in early veliger and begins to differentiate into basophilic cells and digestive cells in mid veliger. The acidophilic cytoplasm of basophilic cells is gradually changed into basophilic one. Refractile spherules containing iron begin to appear in the basophlic cells since the stage of larva with pallial tentacle. As creeping larva feeds, digestive cells show endocytosis and contain a number of vesicles. The studies show that structure and function of all digestive organs of 45 d old juvenile are basically similar to ones of adult abalone.