Researchers from Sun Yat-sen University and collaborating institutions have discovered a new species of bumblebee goby on Hengqin Island in Guangdong Province, marking the first recorded presence of this fish genus in China. The discovery and description of Brachygobius jennie, detailed in a newly published study in Zoosystematics and Evolution, expands the known geographical distribution of these small coastal fishes northeastward into the subtropical mangrove wetlands of the Zhujiang River Estuary.

Jiangyan Tian, the first author of this study and a postgraduate student at SYSU under the supervision of Jianrong Huang, recalled: “One day, during fieldwork in the wetlands of the Zhujiang River Estuary, my attention was drawn to small fish living close to the substrate in shallow waters. At first, I thought they were juveniles. However, their body marking pattern did not match that of any fish species known from this region.”

Back in the laboratory, Jianrong Huang encouraged Jiangyan Tian to investigate these specimens further using integrated genetic and morphological approaches. With the assistance of Chunliu Lan and Jianyong Wu, she discovered that they belonged to a previously undescribed species of bumblebee goby. This finding was unexpected, as the fish fauna of this region is generally considered to be relatively well documented.

Sébastien Lavoué, from Universiti Sains Malaysia and co-author of the study, said: “I was excited when Jianrong Huang and his team invited me to collaborate on the description of this species because I had never encountered such a small and distinctive bumblebee goby.”

Exhibiting extreme miniaturisation, Brachygobius jennie is the smallest species within its genus described to date, possibly the smallest fish in China and one of the smallest known fishes in the world, with a maximum standard length of less than nine millimetres.

Brachygobius jennie is distinguished from all other species of bumblebee goby by its unique marking pattern comprising four narrow body bars behind the head, two of which are located past the anal fin base, including a chevron-shaped second bar that extends fully to the midventral line. Genetics confirmed its distinctiveness.

The species has been named Brachygobius jennie, commonly known as Jennie’s Bumblebee Goby, in honour of the South Korean singer Jennie Ruby Jane. Jiangyan Tian who discovered the fish explained: “Listening to the songs of Jennie Ruby Jane during my studies was a constant source of inspiration. Naming this species after her is my way of acknowledging the positive influence she had on my work.”

This study contributes to the field of ichthyology by describing estuarine fishes from Asia, which are still insufficiently characterised and currently under multiple threats. Further, because drastic size reduction forces profound adaptations in anatomy and ecology, the newly identified species offers an important biological model. Indeed, it provides scientists with an organism to study the developmental constraints, physiological trade-offs, and evolutionary mechanisms associated with extreme vertebrate miniaturisation.