SSI Nudibranch Ecology Course

You’ll begin with a meet-and-greet session, course paperwork, and a quick orientation. The theory portion is self-paced via the SSI app or browser, giving you flexibility to explore this colourful subject in depth. Your instructor will review key topics with you in person before your dives.

What You’ll Learn in the Nudibranch Ecology Course Theory:

Nudibranch Biology and Defence – Learn what makes these sea slugs so unique—chemical defences, gills, rhinophores, and vibrant colouration.

Habitats and Nudibranchs of Koh Tao – Explore the diverse reef environments, sand patches, and coral rubble zones where local nudibranch species thrive. Understand how environmental factors like temperature and food availability affect their distribution.

Feeding, Behaviour, and Reproduction – Discover how nudibranchs feed on sponges, hydroids, and sea anemones and how they use what they eat to create toxins or camouflage. Learn about their hermaphroditic reproductive strategies and delicate egg ribbons.

Sea Slug Species Identification – Build skills in spotting key anatomical traits that help distinguish between different species. You’ll use real examples from around Koh Tao to sharpen your ability to recognise subtle differences in colour patterns, body shapes, and habitats.

Conservation and Ecological Role – Study how nudibranchs contribute to reef health and how their sensitivity to change makes them valuable indicators in marine science.

By the end of the theory module, you’ll be prepared to confidently identify nudibranch species and understand their role in the ecosystem. Your instructor will answer questions and provide pro tips on how to find and observe nudibranchs in the wild.

After your theory session and a break for lunch, you’ll head out for two boat dives at macro-rich sites around Koh Tao, where you’ll apply what you’ve learned.

Together with your instructor, you’ll search for nudibranchs of Koh Tao in coral gardens, rubble fields, and rock overhangs. You’ll practise sea slug species identification, observing behaviour, colour variations, and movement patterns.

You’ll also learn techniques for safely documenting nudibranch sightings through photos or note sketches.

These dives will help you build practical confidence in macro observation and fine-tune your eye with the essential skills for macro diving on Koh Tao and marine life surveys. By the end of your training, you’ll be able to recognise multiple nudibranch species and understand how their presence reflects the health of the reef ecosystem.

You must be at least 10 years old to enrol in the Nudibranch Ecology Course. This age limit makes it a great choice for younger certified divers who are fascinated by sea slug species identification and want to begin exploring the world of underwater ecology.

To join this course, you need to be a certified diver, either SSI Open Water Diver or equivalent. This ensures you’re familiar with the basic skills and comfort level required for macro diving around Koh Tao, where we’ll be observing nudibranchs in their natural reef habitats.

You must be medically fit for diving. You can download the required scuba medical form here. If you’re unsure about any medical conditions, please check with your physician or contact us prior to booking.

We recommend that you’ve logged a dive within the last six months to ensure you’re confident in the water. If it’s been a while, no problem, you’ll just have to join our Scuba Review session beforehand so you’re fully prepared to enjoy the course.