饥饿对星斑川鲽消化器官形态结构和组织学的影响

Effects of starvation and subsequent feeding on morphological and histological structure of digestive system in Platichthys stellatus

在温度(19±1)℃、盐度32±1的条件下,对相同规格体质量为(26.02±0.30)g的星斑川鲽(Platichthys stellatus)分别饥饿5、10、15 d(设为S5、S10、S15组),恢复投喂20 d。采用石蜡切片方法观察星斑川鲽消化器官形态结构,分析饥饿和再投喂对其组织学的影响。形态结构方面,S5组变化相对较小,而S10、S15组变化明显,表现在胃体积缩小,壁变薄;肠管壁变薄变透明,肠系膜因脂肪基本消失而萎缩;肝体积明显缩小,颜色由原来的粉红色变为深黄色。组织结构方面,S5组变化相对较小,而S10、S15组均有不同程度的损伤,表现在胃上皮细胞高度减小,细胞界限变得不清晰,胃腺细胞收缩,分泌颗粒减少;肠皱壁高度下降,上皮细胞高度显著降低,纹状缘高度减小甚至消失,杯状细胞有不同程度的增加;肝组织致密,肝细胞体积缩小,脂质空泡数量减少,细胞界限不明显,排列不规则,细胞内分泌颗粒减少。恢复投喂后,各实验组消化器官形态和组织结构均有不同程度的恢复,恢复投喂结束时,仅S5组恢复到对照组水平,S10、S15组均未达到对照组水平。结果表明,星斑川鲽饥饿耐受时间为5～10 d,超过此范围会对星斑川鲽消化系统组织结构造成不可修复的损害。

We evaluated the effects of starvation and subsequent re-feeding on the structure of digestive system in Platichthys stellatus. We documented changes in morphological and histological structure by observation of paraf- fin-sectioned gut tissue. Groups of fish （mean weight 26.02±0.30 g） were starved for 5 （S5）, 10 （S10）, or 15 （S15） days. A control group was fed as normal. All fish were held at at （19±1）℃ and 32＋1 salinity. We observed changes in the morphological structure of individuals in groups S10 and S15. The gastric volume decreased and the gastric wall thinned; the tube wall of the intestine was thinner and transparent while the mesentery was shrunken. The hepatopancreas was atrophied and its color changed from pink to deep yellow. The changes in structure were more evident in groups S10 and S 15 than S5. The height of the epithelial cells, gastric gland cells, and the secretory granules in the stomach all decreased and the cell boundary became blurred. There was a de- crease in the height of the epithelial cells and the rugae in the intestine. The striated border also decreased in height, and was even absent in some individuals. We observed an increase in the number of goblet cells, the he- patic tissue was compacted, and there was a decrease in lipid volume and the number of secretory granules in he- patic cells, while the cell boundary become blurred. We observed some degree of recovery following resumption of feeding. Our results suggest that P stellatus are able to tolerate 5-10 d starvation, beyond which irreparable damage is likely to occur to the histological structures of the digestive system.