Karachi, Jan. 5 -- WWF-Pakistan has cautioned that an invasive fish species has been detected in water bodies across Sindh and Lower Punjab, warning that its spread poses a serious threat to aquatic biodiversity and the fisheries economy, Geo TV.

In a statement released on January 4, the environmental organisation said an "unusual fish" was brought to Karachi Fish Harbour from a dhand near Sukkur. The species was initially described as "alien" because it could not be identified by those who encountered it.

The fish was later confirmed to be an Amazon sailfin catfish. According to WWF-Pakistan, the species has a thick, armoured body covered with bony plates and is not native to Pakistan. It was accidentally introduced into natural water ...