Nudibranch Finder

Updated: Mar 18, 2021

I’ll never forget the first time I showed my grandmother a photo of a nudibranch.

Her response was….. “You went all the way around the world to take photos of little colorful worms?…. That’s the type of thing, that if I saw in my garden, I’d step on!” hahaha, yep, I am not making this up!

She might have just been blowing smoke about stepping on one, but they are certainly not colorful little worms. They are far crazier than most people realize.

Most scuba divers love nudibranchs. They come in all kinds of different colors, a wide variety of shapes and sizes, have unique super powers and due to their lethargic mobility, are super approachable critters.

Either a super large finger or a very small nudibranch

Like all animals, if you don’t wanna see them in an animal jail ( a Zoo or Aquarium) you gotta be able to find them in the wild.

Finding nudibranch

There are several ways you can go about doing this. You can either get your self a good dive guide, train your eyes or rely on dumb luck!

Now, if you're unlucky, your dive buddy can’t find shit and a dive guide is not an option, you're gonna have to know a little bit about nudibranchs in order to increase your odds and success rate of finding them.

For the sake of keeping this article less than 1,000,000 words, I’m only gonna touch base on a few facts about finding nudibranchs and no descriptions will be done in latin. I’ll only be using the common muggle tongue of good ol’ black n’ white english….

Let's Go!


There are thousands of species of nudibranchs. Knowing the stats on all of them is only for the die hard like Ron Silver and Gary Cobb. However thanks to the discoveries and countless pieces of literature from dedicated people like them, it can be much easier for us to find nudibranchs, piggy backing on their life time accomplishments.

Just like most other animals, nudibranchs can be categorized into families, sub families and so on. Why is it helpful to know the families of nudibranchs?

Well, roughly speaking, most species in a family will have similar traits. So when creating a data bank of information in your head, full of indicators and notes on how to find them, it saves a lot of storage space by just remembering information about families rather than individual species.

* Also it will help you better identify them when you get back from your dive, that’s a whole other article coming soon!

I recommend the Nudibranchs Encyclopedia , Nudibranchs of the World and Nudibranchs and Sea Slugs Identification (specific to Indo-Pacific)as good books to start with.


The most important thing you gotta start learning when searching for nudibranchs is knowing where to look.

Some areas underwater offer a much greater chance of finding nudibranchs for one reason or another. You wouldn’t go looking for a hooker in a church….. but every now and then there are some exceptions to the rule!


Instead of just passing by coral rubble and complaining about dead reef, a true nudibranch connoisseur knows this can be a gold mine for finding nudibranchs. Coral rubble provides a wealth of hidden spaces, not only for nudibranchs, but also many other critters found on or near coral reef systems. Nudibranchs will hide in the rubble at night or during the day if they are a nocturnal species. That can use the rubble to lay their eggs, hide from predators and so on. They also use these areas, that may seem small to us but to them are large meadows they can use as paths of transit, breeding grounds, hunting grounds and much more. In my experience finding them, some of the strangest nudibranch I’ve ever found have been hiding in plain site in the middle of coral rubble patches.

Certain species are only ever observed in the muck. What is muck? It's the sandy silty areas most divers don't want to go, but this is where true beauties can be found. Some specie burrow in the ground by day and by night time come out to play.

A huge nudi spitting out another nudi! Can you hear I'm a bit excited. This photo was taken by my guest Steffi during an epic night dive in Papua New Guinea.

knowing what THEY LIKE TO EAT

We’ve all got a food of choice, and nudibranch are no different.

Loads of nudibranch love eating hydroids. Hydroids are a life stage for most animals of the class Hydrozoa, small predators related to jellyfish…..hahaha NOPE!...I'm not going down the hydroid rabbit hole, I’ll let the hydroid people write the hydroid articles.

Basically, to the untrained eye, they look like little plants that grow in the empty spaces of coral reefs. If you’ve ever touched one, you know that they can sting like a mother fucker. Nudibranchs have adapted themselves not only to be able to eat them, but to be able to take it to whole other level.

What they do is, some species store the stinging cells inside their cerata ( the appendages found on some species backs) and will use the stinging cells as defense to protect the nudibranch from predators. That is some crazy ridiculous biology. It’s like if a lion ate a viper and now its fur is venomous….

Well...not quite, but you get the point!

If you find hydroids look for nudibranchs, some species only eat certain hydroids so once you start to learn who eats what, you will start finding them with ease.

Nudibranchs can eat much more than just hydroids. Some species eat algae, sponges, anemones, corals and barnacles. Once again, knowing who eats what can help lead you to finding some pretty cool species.

A few species live exclusively on what they feed on, like the Costasellia Nudibranch , some times better known as Shaun the Sheep.


If you are looking for cannibals, you are in luck... there are still some to be found! Gymnodoris, along with a few other families of nudibranchs love eating other nudibranchs.

Strawberry Gymnodoris

Some eat them whole, kinda like a snake eating a mouse, and some will just eat the lungs of other nudibranch….Super morbid little demons they can be! How can this help you? If you know what species like to eat other nudibranchs, when you find one of them, it’s worth having a look around. It might be on the hunt for dinner and have already detected another nudibranch close by

and could lead you to it!


Some nudibranch only eat the unborn of other nudibranch.

Favorinus, for example, is a family of nudibranch that can be often found munching down on nudibranch eggs.

Nudibranch eggs can be easy to find due to their shape and size. No, the eggs are not large, they are ridiculously tiny, but the clusters and formations of the eggs can often be much longer than the animal that lays them.

Black margin glossodoris laying eggs

Nudibranch eggs can often take very different formations. One common formation is in an expanding circular ribbon shape. If you find the eggs, have a look around, they could be fresh and it could mean that the nudibranch that laid them is still close by. Also, once you get better at identifying the eggs, you will be able to tell what species are in the area just by looking at the eggs.


Some species of nudibranchs have evolved beautifully to match their surroundings. Just like the pygmy seahorse blends in with a gorgonian sea fans, some species of nudibranch blend in with many other corals, plants hydroids sponges and more.

To find these dudes you’ve gotta look in exactly the right places. On rare occasions you’ll see one of these species moving between locations, but for the most part they are always well placed among the environment for which they so perfectly evolved to blend in with.

Do you see the nudibranch?


Some species only come out during the day and some only at night. The Spanish dancer for example is the largest known species of nudibranch and only comes out to play at night.

Also it can be that some species are seasonal. You can always contact somebody from the location you want to dive and they might be able to give you more information about the seasonality of the nudibranchs in the area.

The big fat Spanish Dancer


Sometimes it all boils down to complete and utter randomness. I used to play a game with my wife to see who could spot a nudibranch the fastest. One day while diving in Thailand, as my eyes descended below the water at the beginning of the dive, instantly I spotted a nudibranch floating by, in the blue. Not even one second into the dive. Sometimes you really can't predict where or when you are gonna find them.

A nudibranch floating in the water.... this is certainly not an oceanic species!

After all this, it’s no different than finding many other marine critters, it boils down to 2 simple factors. Having good eyes and/or good luck.

Good eyes being a combination of experience and being a student of the game, and good luck, well, we still haven’t quite figured out where that comes from. I’ve always said that my wife’s got better eyes than I do but I’ve got better luck, so at the end of the day we are fortunate to dive together to be able to maximize both attributes.

If you use some of the learn more about some of the criteria outlined above, I guarantee it will help your success rate go up when looking for nudibranchs. This way you can be self reliant when you get a lemon of a dive guide or dive buddy!

If you love nudibranchs as much as we do , have a look at our nudibranch designs in our men’s and women’s sections, we’ve put together a few super unique nudibranch designs we know you'll love!