摘要
利用光镜和透射电镜技术对大菱鲆仔鱼皮肤的发育及超微结构进行了观察.大菱鲆早期仔鱼鱼体两侧皮肤结构完全对称.变态前仔鱼的皮肤发育缓慢,l～25d仔鱼的皮肤由l～2层表皮细胞和不发达的真皮层组成.变态开始后,皮肤的发育速度明显加快.至变态结束(60 d左右),仔鱼的皮肤由3～4层表皮细胞和发达的皮下胶原层组成.随着变态发育,大菱鲆仔鱼有眼侧皮肤与无眼侧皮肤结构上出现差异.超微结构观察显示大菱鲆的表皮包括3种表皮细胞:含微丝细胞,黏液细胞和氯细胞.有眼侧表皮细胞胞质内有大量空泡结构,表皮结构较疏松,仅有1种含微丝细胞.无眼侧表皮细胞胞质密度较高,表皮细胞排列紧密,具有两种结构和电子密度各异的含微丝细胞.在真皮层的疏松结缔组织层中有黑色素胞、虹彩色素胞,纤维芽细胞和其他类型的细胞及组织分布其中,黑色素胞中色素颗粒的密度及分布随仔鱼的发育及皮肤的着色状况而发生变化.这种伴随变态而产生的鱼体两侧皮肤结构的差异,是大菱鲆仔鱼由浮游生活转入底栖生活的一种生态学适应.
Abstract
The histological development and ultrastructure of larval turbot skin were studied by both light and transmission electron microscopes. The early larvae showed a complete bisymmetry of skin. The skin of 1 - 25days old larvae developed slowly and was composed of the thin epidermis of 1 - 2 layers epidermal cells and undeveloped dermis before the metamorphosis. But the skin developed significantly when the metamorphosis began. Till the completion of metamorphosis ( about 60 days old), the skin contained 3 - 4 layers epidermal cells and very developed collagenous strata. With the process of metamorphosis, the ocular side skin and blind side skin became different in ultrastructure. Ultrastructural observation showed the epidermis of turbot contained three types of epidermal cells: filament-containing cells, mucus cells and chloride cells. The ocular side epidermis with looser structure consisted one type of filament-containing cells, but the blind side epidermis was structured densely and two types of filament-containing cells were observed in it. Melanophores, iridophores, fibroblasts and other cell types and tissues were found in the spongiosum of dermis. The distribution of melanophores depended on the larval developing stage and the pigmentation of skin. The differentiation of skin seems to be an adaptation for the change of life style of turbot larvae from pelagic living to benthonic living after the metamorphosis.
基金项目
国家自然科学基金(30070593,39970578)
国家科技期刊平台
NSTL
万方数据