Cave fish research is a field that combines both its fringe nature and significant risks. Heiyu Zhou is an engineer at the Forest Resources Monitoring Center whose work spans multiple aspects of biodiversity surveys—from bats in the order Chiroptera to cave fish, from nature reserve planning to discovering new species.

The mysterious world of cave ecosystems where groundbreaking research meets extreme challenges

After participating in the challenging biodiversity expedition in the Siguniang Mountains, MRS packraft deeply appreciates the difficulties of field research. It’s easy to imagine the time and effort Heiyu Zhou has invested in cave biology, the process of discovering new species, and the sheer number and difficulty of his cave explorations. For this reason, MRS packraft is committed to supporting him with professional gear to facilitate his expeditions.

From Species Research to Deep Cave Biology

MRS packraft: Cave environments are dark and mysterious, with complex amphibian and reptile behaviors. What inspired you to dedicate yourself to studying cave life?

Heiyu Zhou: In Zhejiang Province, China, bat research was virtually unexplored. When I encountered related challenges at work, we had to hire experts from other provinces. Later, my supervisor arranged for me to study under prominent domestic scholars, which introduced me to bat research. Since most bats live in caves, I naturally developed a connection to caves. I had also long been involved in freshwater fish biodiversity studies. Frequent cave visits for bat research became a perfect opportunity to explore cave fish as well.

Bat colonies in cave environments that first drew Heiyu Zhou into the underground world

MRS packraft: Can you share some of the “amazing creatures” you’ve encountered underground? Which one stands out the most?

Heiyu Zhou: The most remarkable is a new cave fish species we published in 2023 called the “Longhorn Golden-line Barbel.” It’s pure white, blind, and has a long “horn” on top of its head. The significance of this “horn” in cave fish evolution remains a mystery to this day.

The newly discovered Longhorn Golden-line Barbel, featuring the mysterious horn structure that puzzles researchers

Groundbreaking Discovery: The 2023 publication of the Longhorn Golden-line Barbel represents a significant milestone in cave fish evolution studies, raising new questions about adaptive mechanisms in extreme environments.

MRS packraft: Have you discovered any previously unrecorded species during your research? Which experience was the most unforgettable?

Heiyu Zhou: China has the highest diversity of cave fish worldwide, but systematic surveys are lacking, so new species are discovered quite frequently. I’ve been involved in describing over ten new cave fish species. The most unforgettable experience was discovering a new golden-line barbel species at the source of the Wang River. We initially planned to film known cave aquatic species but unexpectedly found a potentially new species. Due to inadequate preparation and unfamiliarity with the environment, my graduate student colleague and I got trapped in a sealed cave passage and nearly lost our lives. We were only rescued thanks to government and social rescue teams. This experience remains a “rebirth memory” for me.

The Wang River source cave system where a life-threatening discovery expedition led to both scientific breakthrough and near tragedy

“This experience remains a ‘rebirth memory’ for me.”

Research Challenges and Life-or-Death Moments in Extreme Environments

MRS packraft: Are packrafts critical equipment for cave water surveys?

Heiyu Zhou: In previous surveys, we tried paddleboards, large inflatable boats, and even swimming in wetsuits to navigate underground rivers or work on cave river surfaces. After trying packrafts, their lightweight and reliability clearly make them better suited for cave water biology research. We can carry them easily hundreds of meters down vertical shafts, and their stability reduces the risk of capsizing. Compared to paddleboards, which carry a persistent risk of falling into the water, packrafts improve safety significantly.

MRS packrafts being deployed in underground river systems, demonstrating their superior portability and stability for cave research

MRS packraft: Your cave wildlife footage has been used in popular science documentaries. What practical role does such outreach play in conservation?

Heiyu Zhou: Through a “three-in-one” approach combining visual records, scientific collaboration, and public outreach, we build bridges between government and public awareness of China’s southwestern karst cave ecosystems. Our work showcases the survival wisdom of cave-dwelling species and the wonders of karst ecology, while also highlighting the fragility of these ecosystems. This raises ecological consciousness nationwide and helps rally collective efforts to protect karst geological heritage and endangered cave life.

Underwater photography equipment capturing the hidden beauty of cave ecosystems for scientific documentation and public education

MRS packraft: How can ordinary people get involved in conservation efforts? How does this help your research?

Heiyu Zhou: Our research often benefits from public support: online followers provide clues about cave fish distributions or damage to underground rivers, which can lead to new discoveries or key conservation actions. Additionally, volunteer groups frequently support us with ropes, cave diving assistance, and more, making them vital partners in our research efforts.

Community volunteers and citizen scientists contributing to cave conservation efforts through collaborative research initiatives

The Future of Cave Research: As Heiyu Zhou continues his groundbreaking work, the partnership between advanced equipment like MRS packrafts and dedicated researchers promises to unlock more secrets of China’s vast underground ecosystems while prioritizing both scientific discovery and researcher safety.