In a state-of-the-art laboratory at Shanghai Ocean University (SHOU), Bangladeshi postdoctoral researcher Nusrat Hasan Kanika examines Oujiang color common carp, turning a childhood fascination with colorful creatures into a scientific pursuit.

"I've always been fascinated by vibrant colors in nature," said Kanika. "That's why I chose this lab to study how fish develop their coloration."

Led by Professor Wang Chenghui, the lab has spent nearly three decades on fish germplasm research. Here, Kanika investigates how gut microbiomes influence fish color and growth.

"The gut microbiome plays a crucial role in breaking down food particles, which enhances essential lipids for color formation," she explained. "This not only influences coloration but also boosts growth rate and weight, making fish more productive."

She believes these findings and techniques can benefit fisheries in her homeland.

"Fish with better coloration attract higher market prices in both ornamental and food fish sectors," she noted. "Bangladesh, often called the 'riverine country', has fertile soil and abundant water resources, but we need advanced techniques to maximize production."

In the same lab, Pakistani postdoctoral researcher Rabia Tahir explores how environmental stress affects fish pigmentation and growth. According to her, understanding how to optimize the production of common carp has global relevance, especially amid mounting environmental challenges.

"Fish respond to stress in ways similar to humans," Tahir explained. "With rising global temperatures influencing fish gene activity, our lab experiments help us understand how environmental factors impact them."

She chose to remain in China after her PhD, attracted by the country's cutting-edge facilities and collaborative environment.

"China leads in research technologies and practical applications," she said. "Here, we work with experts and students from around the world, tackling global challenges together."

Another Pakistani doctoral student, Ayesha Arif, studies epigenetics and hybridization, aiming to boost growth through hybrid vigor. It was her childhood curiosity about fish in village ponds that inspired her journey to China.

"In Pakistan, we work with common carp but have limited resources for molecular research," Arif explained. "Here, I have accessed technologies that simply aren't available in my country, where molecular fish research is scarce."

Arif particularly values seeing scientific principles implemented in large-scale operations. "I can now see the expansive, well-managed ponds I once dreamed of in my village, with optimized stocking levels and densities that showcase the potential of good production management."

Much of the lab's research focuses on the Oujiang color common carp, an ancient species native to East China's Zhejiang province. This carp is highly valued both as a food source and for its ornamental appeal.

Over the years, the team has developed improved varieties, including the Longshen No 1 color common carp — a faster-growing strain with stable coloration that addresses long-standing issues like slow growth and genetic degeneration in local populations.

The team is now advancing their work further. "We are currently developing the Longshen No 2 variety," said Wang Jun, a professor involved in the project. "It shows stable red coloration, grows faster than Longshen No 1, and is particularly well-suited for integrated rice-fish farming systems."

According to Wang, the work encompasses genetic evaluation and optimization through family construction, population selection, identification of pigmentation genes, and a continuously refined complementary breeding system.

The laboratory now hosts researchers from Bangladesh, Pakistan, and Egypt, with its findings carrying potential benefits for developing countries worldwide.

Tahir envisions bringing the precision she has witnessed in Chinese fisheries back to Pakistan.

"In China, I've seen how careful monitoring and selective breeding yield exceptional results," she said. "As global challenges like climate change intensify, understanding how aquatic organisms respond is not merely academic — it is essential for food security and sustainable development."

For Kanika, the mission is as personal as it is professional.

Having worked more than 12 hours a day for three years, she is driven by a straightforward conviction: greater food production means healthier, happier populations and faster national development.

"Developing countries must prioritize agriculture for food security," she said."Greater domestic production accelerates national development."

"Fisheries connect scientists, fishermen, and communities across borders," she added. "They remind us that we share a common responsibility to protect and sustain our aquatic health and biodiversity, regardless of where we come from."

zhengzheng@chinadaily.com.cn