Experts caution suckermouth catfish’s impact on endemic aquatic species

Scientists from the Hebbal-based Fisheries Research and Information Centre (FRIC) have urged the need to create awareness among the public, aquarists and hobbyists on the harmful impact of ‘suckermouth catfish’ (an exotic fish species from Northern America) on endemic fish species of an aquatic ecosystem.

A team of scientists – Shivakumar Magada, professor and head of FRIC, and KB Rajanna and C Sruthisree of FRIC – has created an awareness material based on the existing scientific evidences and the team’s observation on this particular species.

Magada told BusinessLine that Hypostomus plecostomus (also known as the suckermouth catfish), which is being traded in the ornamental fish industry, has been introduced to natural waterbodies accidentally and intentionally in many lakes in Bengaluru, wetlands of West Bengal and other major cities in the country.

Stating that ‘suckermouth catfish’ is used as an ornamental fish, he said hobbyists have one or two ‘suckermouth catfish’ in large aquariums and garden ponds to maintain the ponds and aquarium glass clean. Aquariums cannot accommodate them once they grow bigger. In such a situation, many leave them to natural water bodies.

This fish species may not be a serious issue if the numbers are only a few. However, he said, it is advisable not to release them into natural waterbodies. Because when they outreach the number, they become a menace and alter the existing biodiversity of the given ecosystem, he said.

Since they are hardy in nature, they live in derelict water bodies with low oxygen levels. Owing to their armed and spiny body, there are no suitable predators. As a result of this, they slowly establish and increase their population, Magada said.

Threats

Highlighting the major threats from ‘suckermouth catfish’, he said they compete for food and space of bottom feeders and reduce the production and productivity of the ponds and lakes. They dominate the community and population by overgrowth, and eat the eggs of other fishes thereby reducing the numbers of other species.

Stating that it is difficult to eradicate them once these fishes get entry to the natural waterbodies, he said they live in the bottom-most layers. There are no suitable nets to harvest them selectively.

He said that this species is not edible as it has less meat and armed with a spiny body.

There is a need to educate aquarists and hobbyists not to sell these fish in large numbers, and educate fishermen to eradicate this species by burying or for safe disposal.

Fishes of this species grow up to 50 cm, and mature when they reach 15-20 cm. They have a life span of 10-15 years, he added.