凡纳滨对虾越冬亲虾黑鳃病症的初步研究

为确定越冬凡纳滨对虾亲虾黑鳃病症病因,对患病亲虾病因进行分析。结果显示,越冬后患病亲虾鳃部观察到大量线虫。虫体特征显微结构显示,雌、雄性线虫的平均体长分别为(983.6±16.69)μm和(956.9±12.14)μm,虫体表皮不均质,具有2纵列侧分化、4根头刚毛、3个口腔实齿、5个杯形肛前附器,化感器横向扁椭圆形,食道不形成食道球;经鉴定,确定该线虫隶属于色矛科(Chromadoridae)、色矛属(Chromadorella)。组织病理观察结果表明,线虫感染后亲虾鳃组织坏死、溶解,黑色素沉积,游泳足基部出现黑化层。本文报道了一种由色矛线虫引起的越冬亲虾黑鳃病症。

A preliminary study on overwinter diseased broodstock of Litopenaeus vannamei with black-gill

To determine the etiology of broodstock of Litopenaeus vannamei with black-gill disease,the etiology were analyzed in sick broodstock.The results showed that a large number of nematodes were observed in the gill filament of sick broodstock Litopenaeus vannamei.The characteristics of nematodes micro-structure showed that the length of female and male of nematode were(983.6±16.69)μm and(956.9±12.14)μm,respectively.The features were cuticle heterogeneous with lateral differentiation of two longitudinal rows of dots,buccal cavity with three solid teeth,four cephalic setae,five cup-shaped precloacal supplements,amphids transversely oval and curved,and posterior oesophageal bulb not distinctly set off.According to the morphological analysis,the nematodes were identified as Chromadoridae,Chromadorella.Pathological observation showed that after the nematode parasitization,the gill tissues of broodstock were necrosis,dissolution and melanin deposition,while the swim foot base appears black layer.In conclusion,a black-gill disease in broodstock of Litopenaeus vannamei caused by nematode of genus Chromadorella was reported in this paper.