100 Stunning Nudibranchs of Anilao - Nudibranch Capital of The World

Have a look at photos from all kinds of nudibranchs and sea slugs you can spot while SCUBA diving around Anilao, The Philippines. The nudibranch capital of the world at its full glory! Learn the basics and identify nudibranchs you have seen in Anilao with this list and underwater photos.

Have you ever been on a dive where a sea turtle or maybe even a manta ray passes by and you are actually more interested in something tiny bright colored on the reef that might be a nudibranch?!

Quite often you see people for a day of fun diving that are interested in those cartoon-like sea slugs, macro diving or 'treasure hunting'. Maybe it comes with more reef dive experience, maybe it comes with getting more underwater photo/video experience, but as microscopic as those sea slugs might be - nudibranchs are awesome in many ways!

Is finding 'new' nudibranchs a challenge you love while scuba diving? The more unique the better? Then Amazingly Awesome Anilao should be on your wish list, it is located right in the Coral Triangle.

Nudi nerds let's go!

Quick Links

• 10 Nudibranch Basics to Warm-Up
• Scientific Names of Nudibranch - Let's Talk latin!
• Basics and Anatomy for Nudibranch Identification (in short)
• The Best Tools for Nudibranch Identification (You Can Use Offline)
• Anilao - Nudibranch Capital of the World
• Expectation vs reality
• 100 Nudibranch and Sea Slugs of Anilao
• Mimic Nudibranch

10 Nudibranch Basics to Warm-Up

1. A nudibranch is a mollusk (soft-bodied invertebrates) without a shell (when adult).
2. Nudibranch means naked gill, from the Latin words nudus and branchia.
3. There are about 3000 nudibranch species at shallow-water and a few at deep-water.
4. Nudibranch are hermaphrodites (male and female reproductive organs).
5. They lay their eggs in ribbons (flower-like) with protective mucus that take about one week to hatch.
6. Nudibranchs can live up to one year.
7. Some nudibranchs can grow larger than 50cm / 20 inch (Hexabranchus sanguineus) while others are smaller than your eyes can see - but I guess you are already aware of this :))
8. Nudibranch are carnivores; many eat sponges, corals, anemones and other nudibranchs.
9. The stunning colors come from the food they eat and some can also store some toxins from their prey.
10. These bright colors and impressive patterns are for camouflage (blend in) and defense (not eatable).

Scientific Names of Nudibranch - Let's Talk latin!

Common names of marine life species are often a lot easier than the scientific names and for sure a lot more fun. Spanish dancer, blue dragon, sea bunny, polka dot and pyjama nudibranch - tell those in a dive briefing and divers get excited!

Polka dot nudibranch is a lot easier than Jorunna funebris and Pyjama nudibranch is easier than Chromodoris elisabethina.

One of the first problems here is that people use different common names for the same species and they were all made up. So a Jorunna funebris is also often called a dotted nudibranch or even black and white nudibranch. Well, as you probably can image there are more black and white nudibranch species and many nudibranchs have dots... So that does not really work.

The second problem is that you can get very creative with common names making it hard to distinguish the species. Patterns of a pyjama and polka dots are not always the same, you could have a pyjama with polka dots...

Therefore the use of scientific names is quite simply the best way to identify nudibranch, they are always the same - but different theories apply. The scientific nudibranch and sea slug names you can find here come from the theory of Gosliner et al. and their reasoning.

Still you need to identify the species correctly and that can be a real challenge as there can be minor differences. But that might just be the best part for some nudi lovers...

Nudibranch and Sea slug Taxonomy - More Latin...

All nudibranchs are sea slugs, but not all sea slugs are nudibranch. This is similar to: All turtles are animals but not animals are turtles.

In biology animals and plants are categorized by family trees, this is called taxonomy. Within the tree of animals you can find turtles as well as sea slugs at lower levels (classification) but not at the same branch.

Especially when it comes to nudibranch identification it is interesting to know more about taxonomy. It is not easy, because what you call a nudibranch might not even belong to the nudibranch family or a few higher classifications (flatworms for example).

If you start from the trunk you can say they are all Mollusks. Mollusks are soft-bodied invertebrates. From there you can go to Gastropods (all kinds of snails), than to Heterobranchia (sea slugs and sea snails), to Euthyneura (certain anatomy features), to Nudiplura (sea snails and sea slugs without a shell (when adult) to Nudibranchia (specific types of sea slugs without a shell (when adult). This is just to give you an idea. The specifics depends on who's theory you are following and I guess it is maybe not so important for identifying your nudibranchs...

What is important is that there are four species of nudibranchs: Doridaceans, Aeolidaceans, Dendrotaceans and Arminaceans. The two most common species of nudibranchs are dorids and aeolids.

Unless you want to get more into scientific research I guess all you want to know is the 'basics for nudibranch identification', to understand some differences and to save time figuring out what beautiful creature you have seen underwater.

So how to easily identify those four species of nudibranch? Let's start with describing their body structure.

Basics and Anatomy for Nudibranch Identification (in short)

To identify nudibranchs you can start with the shape of the body, the external anatomy. If you look at the image of the Tambja verconis you can learn some basics for identification.

The horn-like tentacles they have on their head are rhinophores, they are for detecting odor (smell) and they can be retracted when a predator comes around. The pompom on his back is a branchial plume, gills to filter oxygen from the water (breathe). This is typical for dorid nudibranchs.

Some species have more tentacles; some facing forward (oral tentacles), some facing to the side (propodial tentacles). If they have a lot of tentacles or finger-like things on their back they are likely to be cerata. This is typical for aeolid nudibranchs.

The mantle is the overall cover, it can be skirt-like that can blow upwards (like a Marilyn Monroe moment).

Coloring is important, especially the location of the colors and the patterns. Think of recognizing horizontal or vertical stripes, lines around the rhinophores, etc.

Searching those details online nowadays might get you a lot closer to the exact species name, but it is also tricky. Therefore it is always good to check and verify the nudibranch name you found with expert knowledge. Quite likely you will learn a lot more and grow your own nudibranch knowlegde as well, yeah!

The Best Tools for Nudibranch Identification (You Can Use Offline)

When you go on a dive holiday you probably have enough luggage to carry around and check-in already. Save travel weight, save a tree and always have these handy with you on your phone or tablet (no WiFi needed):

You should get the Nudibranch and Sea Slug Identification Identification – Indo-Pacific PDF ebook by Terrence Gosliner, Ángel Valdés and David Behrens. This is one of the marine life identification books you can often find at dive shops and on liveaboards - they are simply the best and luckily now available in PDF. It contains over 2000 nudibranch species!

Also make sure to get this Nudibranch Identification App by Gary Cobb to learn a lot more about nudibranch, species, families and identification. New nudibranchs names and species are added when needed, so it always up-to-date. This App has been very useful to me, highly recommended and works without internet connection.

Gary Cobb is a well-known nudibranch expert and his mobile apps are great resources. In fact he personally helped me with identifying some of the nudibranchs you can see on this page - how awesome!

Anilao - Nudibranch Capital of The World

Nicknamed the nudibranch capital of the world, Anilao has a stunning diversity and quantity of nudibranchs and sea slugs. It is one of the SCUBA diving areas where you can spot the most nudibranchs in tropical waters.

It is incredible how many nudibranchs you can spot during a single dive around Anilao (Mabini, Batangas). Often you see different species of nudibranchs in one small area and you rarely only see one of the same species, they seem very 'productive' around here..

To give you an idea of how busy it is in the nudibranch capital of the world I have added some photos below. This is a dive area where dive centers can guarantee that you will see nudibranchs!

Expectation vs reality

The most beautiful nudibranch around Anilao are often of microscopic size... Make sure to get some magnifying lenses for your dive mask .

100 Nudibranch and Sea Slugs of Anilao

Scroll down and mouse-over or click on the photos to see the nudibranch and sea slug ID's.

Nudibranch eggs

Mimic Nudibranchs

Mimic Nudibranchs - Not the real names, but I hope to make you smile. Mimicry is all around.

If you managed to read or scroll all the way to this point I guess you can call yourself a nudi nerd too! Or were you really counting to see if there are really 100 nudibranch on this page? Well, nerd for sure. :)

Make sure to read the main article about Diving around Anilao as well.

If you have anything to add or just want to talk about nudis just get in touch and let's share the fun!

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