WWF warns invasive Amazon sailfin catfish is spreading in Pakistan

WWF-Pakistan says an invasive fish species has been detected in water bodies across Sindh and Lower Punjab, warning it could damage aquatic biodiversity and hurt the fisheries economy. The organisation said an unfamiliar fish brought to Karachi Fish Harbour from an area near Sukkur on January 4 was initially treated as an unknown “alien” specimen before being identified.

According to WWF-Pakistan, the fish is the Amazon sailfin catfish, an aquarium species native to Latin America with a tough, armoured body. The group said the species is a highly successful invader and, given how widely it has spread, eradication and effective control are no longer realistic.

WWF-Pakistan said invasive fish can destabilise ecosystems by outcompeting native species, preying on them, spreading disease and altering habitats, leading to biodiversity loss and economic harm. The statement also traced Pakistan’s history of introducing non-native fish for production and weed control, noting that several introductions later became invasive and disrupted local ecosystems.

The organisation cited past impacts such as reduced fish production in major lakes and resulting socio-economic consequences for fishing communities. It added that beyond deliberate stocking, some species enter natural waters through poor handling and disposal within the aquarium trade, increasing risks around urban and peri-urban water bodies.