A new species of sea slug smaller than a grain of rice has been discovered off the coast of Keelung in northern Taiwan. The translucent marine creature covered in distinctive black and yellow markings has been officially named Tecasera Sesama By researchers from National Taiwan Ocean University, National Museum of Natural Science, and National Taipei University of Education.
This unusual name comes from the slug’s resemblance to a sesame seed. “Taiwanese divers call it ‘sesame’ in Chinese, and it got this name because it is small like a sesame seed,” the research team explained.
The tiny sea slug, less than 3 millimeters long, was first discovered by lead author Hoyoung Chan during a recreational dive in 2019.
A chance discovery led to the identification of a new species
The discovery was unexpected when Chan was still an undergraduate. “During summer recreational diving during HY Chan’s undergraduate study abroad in 2019, he accidentally discovered Tecasera Sesama sp. in the waters north of Taiwan in November,” the researchers said.
At first, Chan did not realize that he had discovered a species unknown to science. The breakthrough came after contacting a sea slug expert online. According to the team, he was “completely oblivious” Tecasera Sesama Sea slugs were a new species until I consulted a sea slug expert, Dr. Hsini Lin, on Facebook. ”
Harsh conditions made research difficult
This type of research has proven difficult due to unpredictable conditions along the coastline of northern Taiwan. The researchers explained that strong seasonal weather patterns severely limit opportunities for underwater exploration.
Typhoons occur regularly in Taiwan during the summer, but during the winter monsoon season, the waves are large and the water temperature is low. Sea temperatures can drop below 16 degrees Celsius, making diving conditions difficult during most of the year. Because of this, researchers can only study sea slugs for about four months a year.
Scientists noted that discovering such small marine animals is often a matter of luck due to their size and limited research space.
A small sea slug with a simple lifestyle
The researchers observed that Q. Friends appear to spend their lives focusing on just four main activities: feeding, exploring, mating, and spawning. This species was found living in bryozoans, small aquatic invertebrates commonly known as “bryozoans.”
Interestingly, the bryozoan species that serve as habitat for nudibranchs may themselves have been previously unknown to science.
Hidden marine life still waiting to be discovered
Despite their small size, sea slugs play an important role in the marine ecosystem. “Nudibranchs are one of the major players in the marine food web,” the research team explained. “They are very colorful and can be found in coral reef ecosystems. However, many nudibranchs are very small in size and are therefore very difficult to spot with the naked eye underwater.”
Researchers believe the following findings Tecasera Sesama This may only represent a small part of Taiwan’s hidden marine biodiversity. Many marine species are small and easily overlooked, leading scientists to believe that there are many more creatures yet to be discovered.
research to explain Tecasera Sesama Published in an open access journal Zookie May 11, 2026.
