运输胁迫对四指马鲅幼鱼肝脏、鳃和脾脏组织结构的影响

Effects of transport stress on liver,gill and spleen tissue structure of juvenile Eleutheronema tetradactylum

【目的】探究运输胁迫对四指马鲅(Eleutheronema tetradactylum)幼鱼肝脏、鳃、脾脏组织结构的影响,提高种苗运输存活率,为其规模化养殖提供技术支持。【方法】以四指马鲅幼鱼为研究对象,分别设对照组(未运输)、混合组(运输,同时添加抗应激混合物)和空白组(运输,不添加任何抗应激剂),抗应激剂为维生素C∶谷氨酰胺=1∶1。混合组和空白组幼鱼经6 h运输后分别取样(肝脏、鳃和脾脏),经石蜡切片和HE染色,显微镜下观察测定肝脏、鳃和脾脏的细胞形态、组织结构、生活及生理状态。【结果】对照组幼鱼表现正常,未出现死亡现象,混合组幼鱼的累计死亡率为12.5%,空白组的累计死亡达27.5%。对照组幼鱼的各组织均呈正常形态;混合组幼鱼的肝脏部分区域细胞排列疏松,肝小板结构不清晰;空白组幼鱼的肝脏组织整体失去固有形态,肝小板结构消失不见,大部分细胞核变性呈椭圆形或纺锤形。混合组幼鱼的鳃丝排列混乱,少数鳃小片末端或整体肿胀,血窦内红细胞出现部分堆积现象,线粒体丰富细胞体积变大;空白组的鳃小片整体肿胀,血窦加粗,部分鳃小片因红细胞过多而胀破,线粒体丰富细胞体积变大且数量增多。混合组幼鱼的脾脏白髓区域相对增大,黑色素—巨噬细胞中心数量及大小均有所增加;空白组幼鱼的脾脏组织红髓区域占据大部分,白髓区域相对较少,呈零散分布,巨噬细胞中心减小。【结论】运输胁迫导致四指马鲅幼鱼肝脏、鳃及脾脏组织损伤,抗应激剂混合物虽然在一定程度上起到缓解作用,但并不能完全消除。

【Objective】The effects of transport stress on liver,gill and spleen tissue structure of juvenile Eleutheronema tetradactylum were studied in order to improve survival rate of it and provide technical support for mass production of this species.【Method】As the research object,juvenile E.tetradactylum were divided into control group(no transport),mixed group(transport,while adding anti stress mixture)and blank group(transport,adding no anti stress agent).The anti stress agent was vitamin C∶glutamine=1∶1.Mixed group and blank group juvenile were sampled(liver,gill and spleen)6h after transport,cell morphology,tissue structure,life and physiological state were observed by paraffin section and HE staining under microscope.【Result】The results showed that normal performance and no death was found in the control group,mortality rate was12.5%in mixed group,and the cumulative death in the blank group was27.5%.Normal morphology was observed referring to the tissues in the control group.Cells arranged loosely in part of the of juvenile liver,and liver plate structure was not clear in mixed group.The liver tissue lost its intrinsic shape as a whole,liver plate structure disappeared and most nucleus were denaturation in oval or fusiform shape.The gill filaments were arranged irregularly,and a few or the whole of gill fragments swelling,red blood cells accumulated in part of the sinus,and mitochondria rich cells became larger in mixed group.Gill lamella swelled generally,the blood sinus broadened,part of the gill lamellae was busted because of too many red blood cells inside,and the mitochondria rich cells became larger and the number increased in blank transport group.The areas of white pulp of spleen increased and the number and size of melanin-macrophage centers increased in mixed group.The red pulp took up a majority area of spleen tissue,while the white pulp area was relatively smaller and distributed scatteredly,and the melano-macrophage centers(MMCs was reduced in blank transport group.【Conclusion】The results of this study indicate that transport stress results in liver,gill and spleen tissue damage in juvenile E.tetradactylum.Although a mixture of anti stress drugs can act as a relief to some extent,the damage can not be completely eliminated.