Nudibranch Ecology
They are everywhere on the reef, tiny and extraordinary. Most divers swim right past them.
Identification, behavior, and ecological role of nudibranchs. The course that turns a slow, methodical dive into one of the most rewarding kinds.
Availability: Contact us for booking information
They Are Everywhere on the Reef, Tiny and Extraordinary. Most Divers Swim Right Past Them.
Nudibranchs are some of the most colorful, strange, and genuinely diverse animals in the ocean, shell-less sea slugs that breathe through exposed gills, defend themselves with chemicals stolen from their prey, and come in forms ranging from smooth and simple to elaborately branched. Most divers finning past one have no idea what they are looking at.
SSI Nudibranch Ecology teaches you to recognize the major groups of sea slugs, understand nudibranch anatomy, movement, and reproduction, and slow down enough to actually find them. Self-paced academics, with an optional open water application dive. $150. Open to everyone, certified diver or not. Minimum age 10.
This Is Knowledge, Not a Skill Gap
Nudibranch Ecology is not about being a more advanced diver. It is about finally noticing, and understanding, one of the most rewarding groups of animals on any reef.
This course exists to turn a slow, methodical dive into one of the most genuinely rewarding kinds, once you know what to look for and where.
Is this you?
Nudibranch Ecology Is for the Diver Who Slows Down and Looks Closely
Tap to expand
This is usually the right next step if any of these sound familiar.
You are drawn to small, colorful, and unusual subjects
Nudibranchs are among the most photogenic animals on any reef, and this course explains what makes each one distinct.
You enjoy slow, methodical dives focused on small finds
Nudibranch hunting rewards exactly this style of diving.
You want to tell a dorid from a cladobranch nudibranch
This course covers the real anatomical groups behind the huge variety of sea slug appearances.
You want the specialist companion to Marine Invertebrate Ecology
Marine Invertebrate Ecology covers the whole range. This course goes deep on one spectacular group within it.
Not sure?
Choose Your Explore-Lane Course
Tap to expand
You want to go deep on sea slugs specifically
Best for divers drawn to macro subjects and methodical, close-focus diving.
You want the broader foundation first
Best for understanding the full range of reef invertebrates before specializing.
You want to focus on the reef structure instead
Best for divers focused on identifying coral families and reef health.
Setting the record straight
What Nudibranch Ecology Actually Covers
Tap to expand
"They’re just slugs, nothing interesting about them."
Nudibranchs display extraordinary diversity in form, movement, and chemical defense, some even retain stinging cells from the prey they eat and redeploy them for their own defense.
"It’s too hard to find them without a guide."
This course teaches you what habitats and behaviors to look for, so you know where and how to look, not just what you are seeing once you find one.
"All sea slugs are nudibranchs."
Nudibranchs are the largest of five major sea slug groups covered in this course, alongside headshield slugs, sap-sucking slugs, sea hares, and sidegill slugs.
"This is too niche to be worth a full course."
Nudibranch diversity, anatomy, movement, sensory systems, and reproduction, is genuinely rich enough to reward focused study, and changes how you dive.
What You’ll Train
Primarily an academic course, with an optional open water application dive.
The five major sea slug groups, headshield slugs, sap-sucking slugs, sea hares, sidegill slugs, and nudibranchs, and the physical characteristics and sensory tentacles that distinguish them.
How sea slugs move and behave, and their sensory and respiratory organs, including chemosensory detection and exposed gill respiration.
Mating and reciprocal copulation, egg masses, life span, and the symbiotic relationships nudibranchs form with their prey and environment.
An optional dive applying what you have learned to find and identify sea slug groups in a real environment.
Course at a Glance
| Price | $150 |
| Format | Online academics via MySSI app · optional open water application dive |
| Prerequisites | None required for academics · Open Water Diver if completing the optional dive · minimum age 10 |
| Certification awarded | SSI Nudibranch Ecology · lifetime certification, recognized worldwide |
Ready to actually notice them?
SSI Nudibranch Ecology: $150 · Austin, TX
Self-paced academics, open to every diver. Call (512) 451-3425.
Register Here Call Tom’s Email Tom’sWhere this fits in your pathway
Nudibranch Ecology Sits in the Explore & Enrichment Pathway
Tap to expand
Explore & Enrichment is about conservation and knowledge, open to everyone regardless of experience level. Nudibranch Ecology pairs naturally with Marine Invertebrate Ecology and Coral Identification for a complete picture of small reef life.
Control / Comfort
Buoyancy, navigation, boat procedures, and other confidence-building skills.
Explore & Enrichment
Marine ecology, nudibranch ecology, and other ways to understand what you are seeing underwater.
Optimize
Nitrox, computers, equipment, and other tools that make diving more efficient once your basics are dialed in.
Why Tom’s Dive & Swim
We Build Divers We Would Trust With Our Own Families.
Tap to expand
The best divers don’t chase certifications. They build capabilities. Finding and identifying nudibranchs is a direct example: it rewards patience and close observation with some of the most rewarding sightings in diving.
Tom’s teaches ecology with a focus on what you will actually encounter on travel destinations, not abstract theory. Tom’s has been Austin’s only SSI Dive Center since 1982. We were teaching scuba in Austin before any of the other Austin dive shops opened. Over 18,000 certified divers and over 400 five-star Google reviews.
Built Around What You’ll Actually See
Curriculum connects directly to the sea slugs Austin divers actually encounter while traveling.
Open Longer Than Any Other Austin Dive Shop Still in Business
Four decades of helping Austin divers understand and appreciate what they are seeing underwater.
No Prerequisites Required
Academics are open to anyone curious about nudibranchs, certified diver or not.
One of Austin’s Largest Instructor Teams
Available to answer questions and discuss the material beyond the self-paced curriculum.
We follow DAN dive safety protocols.
Tom’s follows Divers Alert Network (DAN) safety standards and recommends DAN dive accident insurance for every certified diver. Safety is not a checkbox on our website. It is the foundation of how Tom’s has operated since 1982.
Frequently Asked Questions
Tap any question to expand the answer.
Do I need to be certified to take this course?
No. The academic portion is open to anyone. You only need Open Water certification if you choose to complete the optional open water application dive.
Are all sea slugs nudibranchs?
No. Nudibranchs are the largest of five major sea slug groups this course covers, alongside headshield slugs, sap-sucking slugs, sea hares, and sidegill slugs.
Will this help with macro photography?
Yes. Nudibranchs are among the most popular macro photography subjects, and this course explains what makes each type distinct.
Is this the same as Marine Invertebrate Ecology?
No. Marine Invertebrate Ecology covers the full range of reef invertebrates. Nudibranch Ecology goes deep on this one spectacular group.
Can I bundle this with other Explore courses?
Call (512) 451-3425 to ask about current Ecology Class bundle pricing for combining multiple Explore-lane courses.
Book online, call, or email, whichever is easiest for you.