Objective: The study aimed to determine the concentration of three heavy metals namely, lead (Pb), cadmium (Cd) and chromium (Cr) present in head, stomach and muscle parts of Nile Tilapia (Oreochromis niloticu) and Blackchin Tilapia (Sarotherodon melanotheron) collected from different sampling sites in South Bay area of Laguna Lake and evaluate its potential health risk for adult consumers. Methods: Live samples of Nile Tilapia and Blackchin Tilapia were hand-collected from three sites of South Bay of Laguna Lake during wet season. Raw and boiled samples were prepared for analysis. Heavy metal concentrations (mg kg-1) were determined through flame atomic absorption spectrophotometry (AAS). The potential health risk posed by more than one metal was calculated using the Total Hazard Quotient (THQ). Results: The heavy metal detected with the highest concentration was Pb, present in Nile Tilapia. The mean concentrations of Pb, Cd, and Cr in both fish samples were high in the head part. Boiled samples have significantly lower concentrations of heavy metal (p<0.05) compared to raw samples. THQ values for Cd in raw fish samples were higher than the recommended level of exposure (THQ < 1.0). Conclusion The study revealed that cadmium is of greater concern in terms of possible adverse health effects associated with heavy metal bioaccumulation. However, the presence of other metals may further increase the risk of non-carcinogenic adverse effects. The lower health risk is predicted for boiled fish samples.
Metals, Heavy ; Cichlids

Acanthogyrus (Acanthosentis) tilapiae parasites were collected from the intestines of 300 fish belonging to three tilapia species sourced at the River Nile, Giza, Egypt. The proboscis of the parasite was characterized by three rows of hooks that curved towards the posterior of the body. The first row is supported by unmodified hooks. The parasite tegument has a series of alternative folds and a large number of pores. Sensory ganglia are located on the surface of the proboscis and body. Acanthogyrus (Acanthosentis) tilapiae provokes an aggressive host response indicated by hyperplasia of the intestinal goblet cells and focal eosinophil infiltrations. This acanthocephalan parasite shows a highly modified adaptation to its site of host infection.
Acanthocephala/*anatomy & histology/*physiology/ultrastructure ; Adaptation, Physiological ; Animals ; *Cichlids ; Egypt ; Female ; Fish Diseases/*parasitology ; Histocytochemistry/veterinary ; Intestines/parasitology ; Male ; Microscopy, Electron, Scanning/veterinary