The present context is a pioneer attempt to verify the ability of copepod, Lernanthropus kroyeri (L. kroyeri), to uptake and accumulate heavy metals. We primarily assess the prevalence of the parasite in various seasons and its clinical signs, as well as post-mortem changes in sea bass (Moron labrax). The morphological features of the parasite using a light microscope, the bioaccumulation of heavy metals in the tissues of both L. kroyeri and M. labrax (gills, muscles) using Flame Atomic Absorption Spectrometry, and the histopathological alterations were monitored. Fish (n=200) were obtained from Ezbet Elborg and examined for the parasite, L. kroyeri. The results revealed that the total infection was recorded at 86%. The infested fish exhibited excessive mucous and ulceration at the site of attachment. The post-mortem lesion in the gills revealed a marbling appearance with destructed filaments.