Through the work of Patrick Kestemont, UNamur is contributing to the captive breeding of a catfish adapted to the saltwater of the Mekong River

In the Mekong Delta, aquaculture is increasingly facing the encroachment of saltwater into areas that are typically supplied with freshwater. This phenomenon, known as salinity intrusion, can make it more difficult to farm certain locally raised species. 

It is against this backdrop that the DIVERSAQUA project is being carried out, funded by ARES-CCI and coordinated by Professor Patrick Kestemont of UNamur and Professor Nguyen Thanh Phuong of Can Tho University. The project also involves the University of Liège. Its goal is to identify and better manage the farming of species capable of withstanding these changes in salinity. 

The researchers focused on Pangasius krempfi, known locally as ca bong lau or ca dua. This catfish is considered euryhaline, meaning it can live in waters with varying salinity levels. This characteristic makes it a particularly promising candidate for areas of the Mekong Delta that are increasingly affected by saltwater intrusion. 

The species also has other advantages: it can grow to a large size, its flesh is highly prized, and it has significant economic value. In the delta, it is found primarily in estuaries and coastal areas. Until now, however, its aquaculture has remained limited.  

After more than two years of work, the project teams succeeded in raising wild juvenile fish to adulthood in a closed-loop aquaculture system, where the water is filtered and reused. The mature fish were then induced to reproduce using hormones commonly used in aquaculture. The resulting larvae were recently reared in tanks until they reached the juvenile stage. Eventually, these animals could become the first fully domesticated broodstock of the species.

The goal is to gradually produce the juvenile fish needed for aquaculture without relying solely on wild populations. This would ensure a more consistent supply and allow for continued research into the commercial farming of the species. 

At the same time, researchers are also studying Pangasius krempfi’s ability to tolerate different salt concentrations. Several experiments are being conducted at various stages of its development—from the larval stage to the juvenile stage—to better understand its physiological responses and immune system. 

This research should help determine the conditions under which the species can be farmed and more accurately assess its potential in areas subject to saltwater intrusion. In the longer term, the DIVERSAQUA project aims to diversify the species farmed in the Mekong Delta and offer new solutions to aquaculturists facing the effects of climate change. The successful reproduction of Pangasius krempfi in captivity is therefore an important first step in this direction. The teams are now continuing their research with the goal of gaining a better understanding of the species and assessing the conditions necessary for its development on a larger scale. Congratulations to all the researchers involved in the DIVERSAQUA project, and especially to Professor Patrick Kestemont, who coordinates the project for UNamur!