Marine Invertebrate Ecology
The most abundant life on the reef is also the most overlooked. That changes here.
Identification and ecology of the invertebrates that form the structural and biological foundation of every reef ecosystem.
Availability: Contact us for booking information
The Most Abundant Life on the Reef Is Also the Most Overlooked. That Changes Here.
Fish and coral get all the attention, but the sponges, anemones, worms, mollusks, crustaceans, and echinoderms sharing the same reef make up the vast majority of its biodiversity, and most divers swim past every one of them without a second look.
SSI Marine Invertebrate Ecology teaches you to classify and recognize the simple and complex invertebrates that form the structural and biological foundation of every reef. 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
Marine Invertebrate Ecology is not about being a more advanced diver. It is about finally noticing the majority of life on any reef, the animals without backbones that everything else in the ecosystem depends on.
This course exists to turn the overlooked majority of reef life into something you actually notice and understand.
Is this you?
Marine Invertebrate Ecology Is for the Diver Who Wants the Full Picture
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This is usually the right next step if any of these sound familiar.
You are drawn to the small, strange life on the reef
Sponges, worms, mollusks, and crustaceans make some of the most rewarding macro subjects in diving.
You’ve taken Coral or Fish Identification and want the rest
Invertebrates make up the majority of species on any reef. This course fills that gap directly.
You want to understand the foundation of the whole ecosystem
Invertebrates anchor the food web and reef structure that every fish and coral depends on.
You want to know what that thing in the crevice actually was
From nematocysts to spiny skins, this course explains the anatomy behind what you have already seen.
Not sure?
Choose Your Explore-Lane Course
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You want the broad foundation of reef biodiversity
Best for divers who want to understand sponges, cnidarians, mollusks, and more.
You want to go deep on one spectacular group instead
Best for divers specifically drawn to sea slugs and their extraordinary diversity.
You want to focus on reef-building coral specifically
Best for divers focused on identifying coral families and reef structure.
Setting the record straight
What Marine Invertebrate Ecology Actually Covers
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"Invertebrates are just boring background."
They make up the vast majority of species on any reef, and their diversity, from filter-feeding sponges to venomous cnidarians, is genuinely remarkable.
"Coral is a plant, not related to what this course covers."
Coral is itself a cnidarian, an invertebrate, closely related to jellyfish and anemones. This course explains exactly where it fits.
"They don’t do anything interesting since they don’t move much."
Many invertebrates show complex behavior: reproduction strategies, chemical defenses, and symbiotic relationships that rival any vertebrate.
"This is too broad to be useful."
The course organizes invertebrates by clear groups, simple forms like sponges and cnidarians, then more complex forms like worms, mollusks, and echinoderms, so the material stays practical.
What You’ll Train
Primarily an academic course, with an optional open water application dive.
How biodiversity is categorized, and the evolutionary story of how marine invertebrates diversified over time.
Sponges (Porifera), jellyfish, anemones, and corals (Cnidaria), and flatworms (Platyhelminthes), including their physical characteristics, reproduction, and defenses.
Segmented worms (Annelida), mollusks (shells and mantles), arthropods (segmented bodies), and echinoderms (spiny skins), the groups that make up most visible reef invertebrate life.
What a coral reef actually is, its importance and economic value, and the human impacts on invertebrate-built ecosystems.
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 Marine Invertebrate Ecology · lifetime certification, recognized worldwide |
Ready to notice the majority of reef life?
SSI Marine Invertebrate 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
Marine Invertebrate Ecology Sits in the Explore & Enrichment Pathway
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Explore & Enrichment is about conservation and knowledge, open to everyone regardless of experience level. Marine Invertebrate Ecology pairs naturally with Coral Identification and Nudibranch Ecology for a complete picture of reef biodiversity.
Control / Comfort
Buoyancy, navigation, boat procedures, and other confidence-building skills.
Explore & Enrichment
Marine ecology, marine invertebrate 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.
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The best divers don’t chase certifications. They build capabilities. Recognizing invertebrate life is a direct example: it fills in the majority of a reef that most divers never actually notice.
Tom’s teaches ecology with a focus on what you will actually encounter locally and 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 invertebrate life Austin divers actually encounter locally and 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 marine invertebrates, 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
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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.
Is coral covered in this course too?
Coral itself is discussed as a cnidarian, but Coral Identification is the dedicated course for identifying specific coral families and reef structure.
Is this the same as Nudibranch Ecology?
No. This course covers the full range of marine invertebrates. Nudibranch Ecology goes deep on one spectacular group within that range.
Will this help with underwater photography?
Yes. Invertebrates are among the most popular macro photography subjects, and knowing what you are looking at improves both the shot and the caption.
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.