论文部分内容阅读
本文采用石蜡连续切片技术、H.E染色和显微测量法,对四指马鲅(Eleutheronema tetradactylum)早期发育过程中视网膜的结构、分化和形成过程以及视觉特性进行了研究。结果显示,受精后8 h54 min,视杯已经形成。初孵仔鱼视网膜没有分化。2日龄仔鱼可以清晰的辨认出色素上皮层、外核层、内核层和神经节细胞层。3日龄仔鱼内核层已经分化出水平细胞、双极细胞和无长突细胞。4日龄仔鱼视网膜10层结构完整。9日龄至14日龄,外核层胞核数目与神经节细胞数目的比值增大,视网膜会聚程度升高,是该鱼视觉特性发生变化的过渡期,这与其从浮游到浅海中下层和泥沙质海底活动的生态迁移相适应。在生长发育的早期阶段,其视网膜内核层水平细胞仅有1到2层,属于感光系统不甚发达的类型。该鱼在仔鱼浮游生活阶段,视敏度较高,视觉对其行为和摄食活动具有重要作用,适应生活于光照较充足的环境中,转入浅海中下层和泥沙质海底后,光敏度和视敏度均较差,视觉在其行为和摄食活动中不具有主要作用。
In this paper, the structure, differentiation, formation process and visual characteristics of the retina during the early development of Eleutheronema tetradactylum were studied by paraffin serial sectioning, H.E staining and microscopic measurement. The results showed that 8 h54 min after fertilization, optic cup has been formed. Retina of newly hatched larvae did not differentiate. 2-day-old larvae can clearly identify the pigment epithelium, outer nuclear layer, the inner nuclear layer and the ganglion cell layer. 3-day-old larvae have differentiated into horizontal cells, bipolar cells and amacrine cells in the inner nuclear layer. 4-day-old larvae retina 10 layer structure is complete. From 9 days to 14 days of age, the ratio of nuclear number to the number of ganglion cells increased and the degree of retinal convergence increased, which was the transitional period of the visual characteristics of the fish. Silt sandy seabed activity of ecological migration to adapt. In the early stages of growth and development, the level of cells in the retina inner nuclear layer only 1 to 2 layers, belonging to the photosensitive system less developed type. The fish in the larvae of larvae life stage, higher visual acuity, visual behavior and feeding activities play an important role to adapt to living in a more adequate light environment, into the shallow sea and the middle and lower sediment sandy, the sensitivity and Visual acuity is poor, and vision does not play a major role in their behavior and feeding activity.