Biological Characteristics And Harmfullness Of Paradeontacylix Sinensis

A new type of parasitic disease of Fugu spp. broke out in the eastern sea area of Fujian Province in May, 2005. The parasites inhabited the vascular system of Fugu rubripes, which caused severe damage to Fugu spp rubripes and loaded to the mortality almost up to 100%. By field sampling, viviperception, sample staining and measuring, the worm was identified as paradeontacylix sinensis. The relevant materials showed that it was the first time this kind of disease broke out in Fujian sea area, it caused a great threat to the development of fish breeding of Fugu spp.. Given the situation, this paper intended to make a further investigation into the parasite with the aim of offering reliable scientific data for the later effective prevention and control of the disease. The author made a detailed investigation and research into the harmfullness brought about by the disease by means of clinical observation, sampling, fixing, sectioning and found out that at the initial stage the disease did not cause massive deaths of Fugu rubripes, however the appetite declined gradually and ceased eventually. The main nosogenesis of paradeontacylix sinensis was the eggs and adults. With the growth of larva and production of eggs of adults, the eggs deposited in most tissues and organs of the fish and formed a large amount of tubercles, leaded to necrosis of tissues and declining and loss of functions of organs. Meanwhile, the grown-up larva may block the blood vessels, which will result in deaths. The author of the paper conducted a curing experiment by injecting medicine into the muscle with the number of subject fish reaching 3000. The results showed that although the conventional marine vermicides like praziquantel, dipterex could kill the parasites, it may cause blocking of blood vessels and malfunctions of inner organs and deaths in the end. So the curing effect was not ideal. After conducting massive experiments and investigations, the author proposed that the ideal effect could be achieved by a set of comprehensive measures as well as early prevention and treatment. Other effective methods and proposals was also advanced in this paper.