Amyloodinium ocellatum infestation in the broodstock of silver pompano Trachinotus blochii (Lacepede, 1801) and its therapeutic control

Abstract

A case of amyloodiniosis caused by infestation of the dinoflagellate Amyloodinium ocellatum in the silver pompano (Trachinotus blochii) maintained for broodstock development is reported. Grossly, erosion of the operculum and excessive secretion of mucus on gills was observed. Microscopic examination of gill filaments showed the presence of trophonts. Histopathologically, gills showed erosion and necrosis of the primary and secondary lamellae. The causative organism A. ocellatum was identified based on the clinical signs as well as gross and microscopic examinations. Among many treatment methods tested, dip treatment with chloroquine phosphate (500 mg per 100 l of water) or with low saline water mixed with Oodinol 1000 were found useful in healthy maintenance of silver pompano broodstock.