Histopathological Observation of Pelteobagrus vachelli Infected with Ichthyophthirius multifiliis

PurposeTo explore the pathogenic mechanism of Ichthyophthirius multifiliis.

MethodThe skin, gill, gastrointestinal tract, liver, spleen, kidney and heart from infected Pelteobagrus vachelli were sampled from nature diseased fish and stained by HE and AB-PAS to observe the histopathological changes.

ResultsI. multifiliis did slight damage to digestive tract, liver, spleen, kidney and heart, and no parasite was only observed in these organs. However, I. multifiliis contributed to severe damage to gill and skin, I. multifiliis was observed in skin and gill. I. multifiliis infection caused gill filament, branchial arch and gill raker confusion and necrosis, taste bud disappearance or was covered, and proliferation of type V cellula mucipara. I. multifiliis infection caused skin bulge or ulcer, proliferation and necrosis of cellula mucipara and club cells in epidermis, and bulge of dermis to form nipple like structure. Muscle fiber showed granular degeneration, and more severely lysis, inflammatory cells infiltration.

ConclusionSkin and gill were the most damaged organ caused by I. multifiliis, which lead to loss balance of internal environment to death.