Abstract:
The invasion of bivalves by parasitic microalgae Coccomyxa is widespread and causes pathologies and dysfunctions of the organs, especially in the most valuable products: the mantle and the muscle. The pathogenesis of the disease remains completely unknown. In this study, based on a macroscopic examination of Modiolus kurilensis and microalgae count in each infected individual, four stages of disease development with characteristic pathognomonic symptoms were described. During the progression of the disease, the concentration of alkaline phosphatase, glucose, calcium, hemolytic and agglutinating activities, number of basophils, eosinophils, phagocytes, and cells with reactive oxygen species increased in the hemolymph, while number of agranulocytes, cells with lysosomes, dead hemocytes, total protein concentration, as well as the weight of mollusks decreased. In the nephridia and digestive gland, necrosis, invasion of Nematopsis sp., hemocyte infiltration, and fibrosis increased. The ratio of changed tubules and occurrence of granulocytomas increased in the digestive gland, while the base membrane, nephrocytes and concretions changed in the nephridia. This study helps establish the variability of these parameters under normal conditions and their alteration during the disease. Moreover, these findings can be used for veterinary monitoring of the state of bivalves in natural and aquaculture populations.
摘要:
寄生微藻Coccomyxa对双壳类的入侵很普遍,会导致器官的病理和功能障碍,尤其是最有价值的产品:地幔和肌肉。该疾病的发病机制仍然完全未知。在这项研究中,根据对每个受感染个体的库里氏巨藻和微藻计数的宏观检查,描述了具有特征性病理症状的疾病发展的四个阶段。在疾病进展过程中,碱性磷酸酶的浓度,葡萄糖,钙,溶血和凝集活动,嗜碱性粒细胞的数量,嗜酸性粒细胞,吞噬细胞,血淋巴中活性氧增加的细胞,而粒细胞的数量,带有溶酶体的细胞,死血细胞,总蛋白质浓度,以及软体动物的重量下降。在肾炎和消化腺中,坏死,线虫的入侵。,血细胞浸润,纤维化增加。消化腺中改变的小管和粒细胞瘤的发生率增加,而基膜,肾脏病中的肾细胞和结石发生了变化。这项研究有助于确定这些参数在正常条件下的变异性及其在疾病过程中的变化。此外,这些发现可用于兽医监测自然和水产养殖种群中双壳类的状况。