Background: Antibiotic residues discharged into the Persian Gulf pose a high health risk to the ecosystem and the public. This study aimed to investigate the toxicity effects of amoxicillin (AMX), the most common antibiotic residue released by municipal sewage into the marine environment of the northern Persian Gulf, on the growth performance and hematological parameters of Pacific white shrimp (Penaeus vannamei) juveniles.
Methods: For a 60-day experimental trial, shrimps were exposed to different doses (100, 300, and 500 μg/L) within the actual concentration range of AMX discharged into nature. Total length (TL; cm), carapace length (CL in mm), and body weight of shrimps were measured at the beginning and end of the survey. Haemolymph samples were taken to analyze the immunological parameters.
Results: At the end of a 60-day experimental trial, the growth performance indices (WGR%, SGR%, TLI in cm, CLI in mm, and SR%) were not significantly different among the groups (P > 0.05). Although all examined hematological parameters (AST, ALT, ALP, TP, ALB, and IgG) increased in shrimp exposed to AMX residues, only TP showed a significant difference (P < 0.05). The total haemocyte count (THC) and differential haemocyte count (DHC) of shrimp exposed to AMX were significantly different from the control (P < 0.05).
Conclusion: Detecting the ecotoxicological effects of pharmaceuticals on non-target species is essential for maintaining a healthy aquatic ecosystem. These findings show that chronic exposure to these compounds may interfere with the species’ metabolism, offering valuable insights into marine pollution in the Persian Gulf and beyond.