Received: 25-09-2018 / Accepted: 29-01-2019
Swollen siphon disease has been considered as a serious threat to otter clam farming in Vietnam. Virus-like particles (VLPs) were identified asthe main causative agent of the disease, however, the transmission pathway and the pathogenesis of the disease has not been clarified yet. In this study, by using electron microscopy analysis, some host species such as otter clam spat and venerid clam (Tapes dorsatus) were selected to screen for the presence of VLPs and VLPs were further analyzed and described their size, structure and location in the host cells. The studies showed that VLPs were found in otter clam spat that were sampled from the hatchery. This finding indicated that the otter clam spat is one of the causes of spead of the wollen siphon disease in otter clam. VLPs have rod-like shape with the size ranging from 70-90 nm x 600-1.000 nm. They consist of outer shell, outer membrance, inner membrance, coreand are located in the cytoplasm of the host cells. Thesestudiesare playsed as scientific basis for developing strategies for classification of VLPs and control, prevetion and treatment of swollen siphon disease in otter clam.