Control of hookworm disease in cultured Pelteobagrus fulvidraco

[etiology] the pathogen was hook larva (Glochidium sp.). The fertilized eggs of the clam develop into hookworm larvae in the outer Gill cavity of the female clam, then leave the mother body to float in the water, come into contact with the fish body, and parasitize on the fish body. The larvae are metamorphosed by absorbing nutrients from the fish and develop into young clams.

[symptoms] the hook larvae adhere to the fish body with foot filaments and hook the fish's mouth, gills, fins and skin with shell hooks. The fish body is stimulated to cause tissue inflammation and proliferation, and gradually wraps the larvae inside to form cysts.

[epidemic and harm] the disease is mainly prevalent in late spring and early summer, when the hook larvae leave their mother and are suspended in the water. Pelteobagrus fulvidraco is the most ideal host for hook larvae. A small number of larvae generally have little effect on the larger adult fish, but have a greater effect on the fry and summer flower species. After the hook larvae parasitize to the gills and mouth of Pelteobagrus fulvidraco, the fish lose their feeding ability and starve to death, or suffocate the fish due to obstruction of breathing.

[diagnosis] ① can make a preliminary diagnosis according to the symptoms of diseased fish. ② removed the cysts from the fish and observed the hookworm larvae under an anatomical microscope to make a diagnosis.

[prevention] ① cleans the pond thoroughly with quicklime. Or kill the mussels in the pond with tea cakes of 60,80mg / L. ② fish fry and summer flower culture pond can not be mixed culture clam, the influent application of net filtration, in order to prevent hook larvae into the pool with the water. In the early stage of the disease, ③ transferred the diseased fish to the pond without clam and hook larvae, which could control the development of the disease and improve gradually.