A Sesame-Seed-Sized Surprise
Newly identified tiny nudibranch species, Thecacera sesama, feeds
on bryozoans off the coast of northern
Slugs may seem like dull creatures when hanging out in your garden,
but the sea slugs that live in coral gardens are among the most colorful
creatures in the ocean. More than 3,000 species of nudibranchs — marine
sea slugs — exist, and scientists in Taiwan have just named a new one.
While many nudibranchs are similar in size to their terrestrial cousins, the
new one found in Taiwan is barely the size of a sesame seed. That makes
it all the more remarkable that it was discovered by an undergraduate
student on a recreational dive.
Ho-Yeung Chan was diving off the coast of Keelung in northern Taiwan when he discovered the tiny gastropod, just 3 mm long and translucent with black and yellow spots. Wondering what it was, he reached out to a nudibranch expert on Facebook. He learned his happenstance spotting was a new species, now named Thecacera sesama after the seed it resembles.
Though he initially saw it in 2019, it’s taken several years to gather information about the creature due to Taiwan’s difficult weather patterns along the northern coast. Summers bring typhoons, and wintry monsoon seasons drop temperatures below 16 degrees Celsius with rough waves. Researchers therefore only get about four months a year to seek out the tiny animals.
What they have learned is that T. sesama lives a simple life. Living on bryozoans, small invertebrates commonly called “moss animals,” the nudibranch spends its days feeding, searching, mating, and laying eggs.
Scientists suspect many more unidentified species of nudibranchs live in the region. They called the waters around Taiwan a “biodiversity hotspot for marine gastropods,” but it will take luck, persistence, and cooperative weather to discover what other wondrous marine slugs make these waters their home.
Ho-Yeung Chan was diving off the coast of Keelung in northern Taiwan when he discovered the tiny gastropod, just 3 mm long and translucent with black and yellow spots. Wondering what it was, he reached out to a nudibranch expert on Facebook. He learned his happenstance spotting was a new species, now named Thecacera sesama after the seed it resembles.
Though he initially saw it in 2019, it’s taken several years to gather information about the creature due to Taiwan’s difficult weather patterns along the northern coast. Summers bring typhoons, and wintry monsoon seasons drop temperatures below 16 degrees Celsius with rough waves. Researchers therefore only get about four months a year to seek out the tiny animals.
What they have learned is that T. sesama lives a simple life. Living on bryozoans, small invertebrates commonly called “moss animals,” the nudibranch spends its days feeding, searching, mating, and laying eggs.
Scientists suspect many more unidentified species of nudibranchs live in the region. They called the waters around Taiwan a “biodiversity hotspot for marine gastropods,” but it will take luck, persistence, and cooperative weather to discover what other wondrous marine slugs make these waters their home.
