[MANILA] Two ingredients commonly found in chewing gum can make tilapia more resilient to lower temperatures, potentially improving production of the fish during cold seasons, researchers have discovered.

Tilapia farming is a growing industry and source of income for fish farmers across Asia, Africa and Latin America. But the fish’s sensitivity to the cold can be problematic.

Native to Africa, Nile tilapia is a tropical fish, which thrives best in waters of between 26 and 30 degrees Celsius. A decline in temperatures can affect their growth and lead to smaller fish being produced, which means lower profits for farmers in colder months.

The researchers from Egypt and the Philippines found that including lecithin and Arabic gum to the diet of Nile tilapia helped regulate their metabolism, enzyme levels, and minerals, all of which are affected when the fish is exposed to cold environments.

“The findings offer a practical solution for fish farmers, particularly in colder regions,” said Janice Ragaza of Ateneo de Manila University, in the Philippines, co-author of the study.

“It has the potential to improve productivity and reduce losses during the colder months.”

Lecithin is a fat that can be found in a number of foods, including egg yolks and soybeans, while Arabic gum comes from the sap of the Acacia tree.

Fish fed a diet containing four grams per kilogram of Arabic gum and ten grams per kilogram of lecithin showed “significant improvements in growth, survival rates, and antioxidant responses”, according to Ragaza.

Tilapia is becoming increasingly popular among consumers as an affordable source of protein. For fish farmers, it is cost-efficient and hardy – generally being able to survive in poor quality, overcrowded waters.

The Food and Agriculture Organization reports that 5.3 million tonnes of tilapia were harvested in 2022, making it the fourth most harvested aquatic animal.

The world’s top producers are China, Indonesia, Brazil, Egypt, Thailand and the Philippines.

While previous studies have shown that lecithin and Arabic gum can benefit fish, the new study, published in Aquaculture Reports, is the first to use them as a feeding strategy for tilapia in cold environments.

“It was a thorough study,” said Wendy Sealey, fish physiologist at the US Department of Agriculture and president-elect of the World Aquaculture Society, who was not involved in the research.

The two ingredients together seemed to have an effect on a specific gene in tilapia responsible for the fluidity of cell membranes, the researchers say.

“The fish that were fed the diet with Arabic gum and lecithin had increased expression of this gene, which likely helped them adapt better to the cold by modifying how their cell membranes respond to temperature changes,” explained Ragaza.

However, these benefits only apply for farms in subtropical regions that experience marginal temperature fluctuations, according to Sealey. In Brazil, for example, most tilapia farms are located in its southern states, where temperatures may be colder in certain months of the year.

“It’s not necessarily for taking tilapia and growing them in Alaska,” said Sealey. “​It’s about maintaining their ability to grow in more marginal areas rather than increasing opportunities for them to grow in super cold climates.”

She believes the findings can be beneficial as the world experiences more intense climactic shifts.

However, she said further investigation was needed, such as observing the tilapia over longer periods of time and investigating at the cellular level.

This piece was produced by SciDev.Net’s Asia & Pacific desk.