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Prevention and control of blood cluster disease of freshwater soft-shelled turtle and turtle

Published: 2024-11-06 Author: mysheen
Last Updated: 2024/11/06, Blood cluster disease is a disease caused by the parasitism of blood cluster worms. Blood cluster worm is a kind of sporozoa, which belongs to true coccidia and kindred worms. The blood cluster worm parasites and propagates in the blood cells, hepatocytes and Kupffer cells of soft-shelled turtles and turtles. (1) pathogenic blood cluster worm. According to Chai Jianyuan et al. (1990), six species of blood cluster insects have been found in soft-shelled turtles and turtles in China. In the soft-shelled turtle (Trionyx sinensis), there are three stages: the merozoite of ① in the mature tissue of liver Kupffer's cells is oval.

Blood cluster disease is a disease caused by the parasitism of blood cluster worms. Blood cluster worm is a kind of sporozoa, which belongs to true coccidia and kindred worms. The blood cluster worm parasites and propagates in the blood cells, hepatocytes and Kupffer cells of soft-shelled turtles and turtles.

(1) pathogen

Blood cluster worms. According to Chai Jianyuan et al. (1990), six species of blood cluster insects have been found in soft-shelled turtles and turtles in China. Now take Haematophila sinensis as an example, in the soft-shelled turtle, there are three stages:

The mature merozoites of ① in liver Kupffer's cells were oval or spherical in size, with a size of 17.92,18.24um × 14.8415.24um, and produced 15-20 merozoites, and the merozoites were short rod-shaped.

The merozoite proliferation of ② in the deep blood occurs in the erythrocytes of the hepatic sinusoids. The merozoites of type X and Y are similar in size and shape, both of which are columnar. Type X merozoites produce 14-18 small merozoites, which are wedge-shaped, and type Y merozoites produce 4-8 large merozoites, which are rod-shaped. The female gamete mother cell is kidney-shaped, and the male gamete mother cell is comma-shaped, with a small tail at the back end.

The initial merozoites of ③ in peripheral blood cells were broad kidney-shaped, producing 6-12 merozoites and banana-shaped merozoites, 6-10 merozoites in middle merozoites and 2 merozoites in late merozoites. The gamete mother cells are derived from Y-type merozoites, and the vegetative body is the intermediate period of development from the previous generation of merozoites to the next generation of merozoites. Soft-shelled turtle (Trionyx sinensis) is the intermediate host of Haematoderma sinensis.

Hirudo sinensis is the final host of S.sinensis. When the leech sucks the blood of diseased soft-shelled turtle, Hirudo sinensis develops in the digestive tract of leech, including two stages of gametogenesis and spore reproduction. The gametogenic tract is characterized by the fusion of bisexual gamete mother cells and then gamete differentiation, resulting in four male gamete nuclei, one of which is fertilized with the female gamete nucleus to form a zygote nucleus. Spore reproduction begins with the mitosis of uninucleate oocysts, and finally forms mature oocysts of 8 naked spores, which disintegrate and release sporozoites.

(2) epidemic situation

According to Chai Jianyuan et al. (1990), 248Chinese soft-shelled turtles, 40 turtles, 25 yellow-margin closed-shell turtles and 2 flat-chested turtles were dissected, but no blood cluster worms were found in flat-chested turtles (because only 2 turtles were examined). The other three species of soft-shelled turtles and turtles were parasitized, of which the infection rate of Chinese soft-shelled turtle was 83.9% and the infection intensity was 19.7% (the infection intensity was calculated by the number of infected red blood cells in 1000 red blood cells). From May to September every year, the infection rate and infection intensity of Haematozoa showed a peak, which was due to the active movement of the host and the exuberant proliferation of Schistosomiasis. Although there are no reports of a large number of deaths of soft-shelled turtles and turtles, with the development of soft-shelled turtle and tortoise breeding industry, if not paid attention to, it is likely to become a serious disease.

(3) symptoms

At present, the intensity of infection is not high, the highest is only 19.7%, so there are no symptoms on the outside. As can be seen from the blood stain, the infected red blood cells are often crowded with blood cluster worms, the nuclei of red blood cells are squeezed to one side, and the cells are seriously dilated and deformed. Lose normal physiological function Especially when the blood cluster worms split and proliferate in the red blood cells, it will cause a large number of red blood cells to disintegrate, and many young red blood cells appear in the peripheral blood, which is a kind of compensatory proliferation. Many pseudopod processes can often be seen on the surface of leukocytes, indicating the enhancement of their physiological activity.

(4) diagnosis

The blood of diseased turtles and turtles were smeared and stained with James sa or hematoxylin and eosin and then observed under microscope.

(5) Preventive measures

(1) remove excessive silt from the bottom of the pool and disinfect it.

(2) when it is found that there are fish leeches on the body surface of soft-shelled turtles and turtles, the pig blood should be sucked with the old loofah stamens in time, and the fish leeches should be trapped in the pool after the blood is solidified, and the leeches should be crushed to death (see the prevention and treatment of fish bdellosis for details).

(6) treatment methods

No research has been carried out yet.

 
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