Koh Tao has many different types of fish and marine life, one of which is the nudibranch.
Nudibranchs (pronounced Noo-di-BRANKs) are gastropod mollusks. That’s a fancy way of saying ‘sea slug.’ Unlike other slugs, nudibranchs possess fantastic coloration and colour patterns. The coloration of each species comes from the prey they eat: the more colourful the prey, the more colourful the nudibranch. There are more than 3,000 species of nudibranch worldwide and more species are being discovered all the time. They crawl slowly across the ocean floor using a single foot, just like a garden snail. Some types of nudibranchs live only a month, while other species live as long as a year. Some species are only about one-quarter inch long at full maturity, others can swell to as long as 12 inches. Nudibranchs have many strange protrusions, including a pair of horn-like tentacles or “rhinophores” worn near the front of their bodies. These horns are primarily chemical sensing organs that help the nudibranch find its prey. Nudibranchs have soft bodies and most lack an external protective shell. This exposure is what inspired their neo-latin/greek name “nudibranch” which means “nude or naked gills.”Without a shell, nudibranchs had to evolve another way to ward off predators. They accomplished this in multiple ways: the development of toxic (aka bad tasting) glands in their skin, and bright colours meant to tell predators that taking a bite is a terrible decision. But that’s not all. Aeolid nudibranchs steal nematocysts (stingers) from the animals it eats (corals, sea anemonesand jelly fish).