A review of toxicological effects of heavy metals on Clarias batrachus

Mo, Cu, Ni, Fe, and Zn are essential heavy metals, whereas Cd, Ni, As, Hg, and Pb are non-essential heavy metals. In humans, essential metals like copper play a key role in regulating metabolism, including the production of hemoglobin and the breakdown of carbohydrates. On the other hand, cells might be damaged by their presence in excess. Heavy metals serve similar purposes in plants, activating enzymes, providing cellular conductivity and ductility, and stabilizing intracellular cations. Some metals are toxic when present in high enough concentrations. Negative effects on human health and decreased agricultural production are associated with essential heavy metal shortages. Even in trace amounts, non-essential metals can cause harm due to their toxic effects. They don't break down or transform into other molecules in the environment's intermediate state. Natural processes such as rock weathering and volcanic eruptions aren't the only ways heavy metals can seep into ecosystems; human activities in the home, workplace, farm, and hospital also contribute. Dangerous, non-biodegradable, and persistent, these metals are everywhere. To put it simply, they wreak havoc on living things. The introduction of heavy metals into the environment sets in motion a cascade of contamination that impacts numerous sectors, including agriculture, urban areas, drinking water, and people's health. Breathing catfish are members of the genus Clarias of the order Siluriformes and the family Clariidae. Because of its ability to go for long periods of time without water, this fish is named after the Greek word for "live," *chlaros*. The genus extends westward to Asia Minor and India, in addition to Southeast Asia, East Asia, Africa, and South and Southeast Asia. In terms of variety, these catfishes are most abundant in Africa.