Trematode infection, Gonapodasmius epinepheli in orange-spotted grouper: Occurrence and histopathological study

Gonapodasmius epinepheli, is a didymozoid trematode encysting on primary lamellae of the gill in orange spotted grouper in south coast of Persian Gulf (Khark Island, Bushehr) Iran. A total of 105 grouper fishes were examined and recorded for the presence of parasites, especially in the gills. The gill filaments with cyst were excised, fixed and stained with Hematoxylin & Eosin and other capsules were stained with Azocarmen stain. Histopathological sections revealed that larvae were primarily embedded underneath the gill epithelium and eggs of the parasite were distributed in some organs such as gill epithelium, heart and macrophages in the kidney.