Physiological status and functional anatomy of zebra fish (Danio rerio) exposed to various levels of Ga³⁺

Gallium (Ga) is one of the intermetallic elements that has been used in cancer treatment for a long time. However, Ga compounds are increasingly being used to make high-speed semiconductors and photoelectric devices. The current work investigated physiological and pathological changes in zebra fish (Danio rerio) exposed to various Ga³⁺ levels (0.55, 1.5, and 3.85 mg/L) over a 14-day test period. Decreases in oxygen consumption were significant (p < 0.05) for groups exposed to 3.85 Ga³⁺ mg/L; this was associated with the fusion of zebra fish gills lamellae. Serum biochemical changes (including aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase) were consistent with observations of damage to organelles within the hepatocytes at higher Ga³⁺ exposure levels (1.5 and 3.85 mg/L) in zebra fish. We propose <0.55 Ga³⁺ mg/L as a biologically safe concentration that can be used to establish water quality criteria for this teleost model.