Nudibranchs: Everybody’s darling

Information on the life and love of nudibranchs and why we can’t get enough of them are presented underneath the photo selection with the name of species shown.

Picture gallery of nudibranchs

with name, location, date and camera settings for each photo as soon as you click on one. As the nudi collection is steadily growing, I decided to divide the gallery starting my personal favourites and adding more species to „Second best of nudibranchs“ at the end of the page as well as additional camera info.

The very best of nudibranchs

Underwater macro shot of Ardeadoris egretta in Wakatobi (Indonesia). This big white nudibranch with yellow-range rim is looking away from the viewer into the dark background.
Underwater macro shot of Mexichromis multituberculata in Lembeh (Indonesia). Small nudibranch laying white eggs around a stick against dark background. Body white to cream-coloured with colical papillae ending inn purple tips, purple rhinophores and purple rim.
Underwater macro shot of Costasiella kuroshimae, also known as Shaun the Sheep, is a species of sacoglossan sea slug, a shell-less marine opisthobranch gastropod mollusk in the family Costasiellidae. This tiny nudibranch has purple to violet tips of papillae and black on the rhinophores, the body is greenish with black spots due to chloroplasts from the algae it feeds on and integrates into its body for photosynthesis.
Underwater macro shot of Doriprismatica atromarginata, Lembeh (Indonesia). Big nudibranch, formally know as Glossodoris has the mantle sitting very high up the foot. Slim black rim around mantle, black ends of rhinophores and darkish to black irreguar patch in the centre of the back and a little on the sides under teh mantle. Base of gills white to cream coloured as the base colour of the whole body and then turning into black.
Underwater macro shot of Phyllidia elegans in Wakatobi (Indonesia). Nudibranch, also known as wartslug, due to their lumpy bodies. Black body and orange rhinophores. Lumpy papillae in greenish to bluish grey, some tips in orange on colourful sponges in orange and purple against black background.
Underwater macro shot of Chromodoris annae in Wakatobi (Indonesia). This nudibranch's body is elongate with a distinctive foot (partially hidden by skirt like mantle in yellow and white). The branched gills and the rhinophores are orange. The main background color is bluish slightly speckled by tiny black spots.
Underwater macro shot of Tenellia sp. crawling towards the viewer (big round black rhinophores, whitish body and cerata in blue with black band before golden/orange tips). Aeolid nudibranch.
Underwater macro shot of Flabellina exoptata in Lembeh (Indonesia). Small aeolid nudibranch with pinkish body and turning into light purple (or lavender) at bottom as well as at the beginning of cerata, then purple band and white-cream tips. Tips of rhinophores are red. Head tenticles blue to purple and oral tenticles more purple to lavender.
Underwater macro shot of two Pteraeolidia ianthina meeting each other in the dark sand of Lembeh (Indonesia). Aeolid nudibranch with striped cerata (brownish, white and bluish). Rhinophores very elongated with purple and whitish stripes.
Underwater macro shot of Glossodoris cincta in Lembeh (Indonesia). Quite the wild looking nudibranch with a sort of red-brown base colour with lots of white-cream speckles all over the body, additioanlly some lumps. The mantle sits quite high on the foot, the rim has a yellow-green and blue band running around. Rhinophores are starting of with red-brown with white speckles, turning into white-cream grooves and ending in a greenish tip.
Phyllidia ocellata in Lembeh (Indonesia). Nudibranch, also known as wartslug, due to their lumpy bodies. Body and rhinophores are orange. Big black spots around some papillae which are greyish.
Underwater macro shot of Hypselodoris tryoni in Lembeh (Indonesia). Beautiful cream coloured nudibranch with purple rim around mantle, purple dots with whitish rim around on body and down to foot under the mantle, branched gills in white-grey and rhinophores purple, black and white.
Underwater macro shot: two nudibranchs (Hypselodoris bullockii) are mating. Purple with red and yellow rhinophores and gills against black background.
Underwater macro shot of Goniobranchus geometricus (black and white with little blue-grey and yellow tips of rhinophores and gills) lifting its head while sitting on a solitary tunicate in orange, purple and white.

Why do we – as almost all divers – go crazy for slugs?

First of all, instead of sea slugs, we lovingly call them nudis, short for nudibranchs, which makes them much cuter and brings out their true nature: beautiful, colourful, and exotic on the one hand, mysterious, bizarre and toxic on the other. Nudibranch families form a sub-group within the large taxonomic class Gastropoda, commonly known as snails and slugs. Granted, while all nudibranchs are sea slugs, not all sea slugs are nudibranchs. We shall try our best to be precise. By the way, the name nudibranch originates from the Latin „nudus“, meaning „naked“, and the Ancient Greek βράγχια (bránkhia) for „gills“.

Second of all, they are a very rewarding find: It is this mix of being super pretty as well as the odd one out. The sheer number of species is astounding. Some are very hard to tell apart, others strikingly different from anything you have ever seen before. They also vary in sizes from tiny speaks of some millimetres to massive beasts. Hexabranchus sanguineus (Spanish Dancer) can grow up to more than 50 cm. Some stand out, others are highly camouflaged.

Thirdly, their senses, behavioural aspects and chemical processes and substances which makes them a promising subject of science. The increase in research has let to the description of new nudibranch species and the reclassification of many others in recent years. The process is still ongoing and leads to some confusion or uncertainties at the moment that we just have to live with for now (read for example on the genus Tenellia / Trinchesia).

That being said: If you spot any mistakes or have any doubts about the names being indicated here, please let us know, we really want to share the correct information and are happy to learn and adapt and go with the flow.

Find the creature

The one thing is finding the species in the wild, another is identifying it afterwards. That’s where pictures are tremendously helpful. Actually, for all ID purposes photos (or videos) are such a useful tool to look up the decisive details to tell certain species apart. I don’t know how often I have put quite some energy into taking a mental picture, only to find myself scratching my head over two different species that pretty much look identical apart from one distinguishing feature which unfortunately didn’t make it into my mental picture. Besides, nudibranchs can be such beautiful macro subjects to work with and get to know your camera setting. Though sometimes, they just crawl over not very photogenic grounds or simply turn their backs on you (as you can see in the gallery quite clearly).

Back on land, we enjoy looking up what we have seen underwater. It starts with dive buddies and colleagues and continues to books and eventually ending in ID groups or website if there is enough internet to do so. Why we care is described in the last section of this page. Even though I plan to add more and more nudis into the gallery above, this is not meant to become a page based or focussed on nudi ID primarily. We name nudibranchs on each photo, add information in little stories and connect other resources. There are very lively communities and growing databases out there which I frequently visit to find out more about my little darlings, like WoRMs (World Register of Marine Species), The Sea Slug Forum, specifically, but not limited to Australia, Nudibranchs where you can also find a very comprehensive list with ID books and other useful resources and, of course, Wikipedia. For a more interactive approach, there are wonderful Facebook groups helping with identification, like Nudibranch Central or Nudi Base.

Why care about the name, a photo or information?

For us, it is a sort of appreciation – we feel grateful to be able to experience nature this way – therefore we want to learn more and more about the underwater world, we love to share our knowledge and passion in the hope to (re)connect us and others to nature more deeply and lovingly. We fully understand not everybody wants to learn the names of the underwater creatures. People go diving for loads of different reasons. But maybe getting to know the world you are entering, might also help with that goal. Let’s see:

  1. We believe you can remember a creature (in fact a whole dive) much better if you know what you saw and what the name of that particular creature is. It works even better to see the name written and/or write it down yourself.
  2. The more you know about the habitat of a creature the more likely you will actually find it on a dive. And isn’t finding a beautiful or special creature yourself the most rewarding part of diving? OK, maybe finding a cool critter and then share it with others is even better! No wait, finding the critter, show it to others after taking a wonderful shot and then sharing the result with even more people, might be the most rewarding …
  3. And, especially interesting for photographers and videographers, even if you know what is out there and where to look for it (some divers leave it all quite happily to their guides) you will actually get better shots knowing the behaviour of your subject as you might be able to anticipate certain movements and bring yourself into the perfect position to frame your picture.

We want to share finds, knowledge and passion in order to connect and inspire on the wonderful topic of nudibranchs – and beyond – as well as diving and photography/videography.

Second best of nudibranchs

Underwater macro shot of two Facelina sp. crawling towrds each other on a piece of soft coral in Lembeh (Indonesia). Aeolid nudibranchs with white bodies and beige to brown cerata. Pink-pur/rpllish rhinophores and base of head tenticle
Underwater macro shot of two Halgerda batangas mating in Lembeh (Indonesia). Nudibranchs with white bodie with fine orange lines running through. Papillae forming irregular spikes on roundish, compact bodies and are ending in orange dots. Rhinophores and gills are black and white speckled.
Underwater macro shot of Halgerda willeyi in Lembeh (Indonesia). Body rigid with a series of acute interconnecting ridges, in dark shades on upper body. The ridges are topped with a yellow or orange line. Black lines going upp from bottom up to the first third of the body only (colour variation). Rhinophores and gills black and white.
Underwater ID shot of Goniobranchus coi. Nudibranch with white and creme to yellow and light brown markings, irrigular wave along the body as a dark line with white rim, mantle slightly purple on edge.
Underwater macro shot of Chromodoris lochi in Wakatobi (Indonesia). Nudibranch with white to blish mantle and light pink rhinophores and gills, black spot on head and black circle along body top.
Underwater macro shot of Mexichromis katalexis in Lembeh (Indonesia). Small nudibranch on dark sediments (white body with lumpy papillae in ending in purple tips, rhinophores also purple, broken orange band around the upper rim of the mantle.
Underwater macro shot of Nembrotha kubaryana in Lembeh (Indonesia). This nudibranch (blue-green body with black stripes, bright red rhinophores and gills) lifts off the ground to determine the way to go.
Underwater macro shot of Pteraeolidia ianthina in Wakatobi (Indonesia). Long and slender aeolid nudibranch with diverted cerata - many variations in colour in this species. This one shows yellow, green, purple and brown with white.
Underwater macro shot of Chromodoris dianae in Wakatobi (Indonesia). Nudibranch with white to gryish body, orange rhinophores and white gills with orange tips on halimeda algae.
Phyllidiopsis shireenae in Lembeh (Indonesia). Nudibranch, also known as wartslug, due to their lumpy bodies. Body and papillae: white/grey with some blue and some distinct black lines running across. Rhinophores pinkish.
Underwtaer macro shot of Hypselodoris emma in Lembeh (Indonesia). Nudibranch with distinctive foot, highly standing, branching gills in red same as rhinophores. Rim of mantle in purple, also 3 purplle lines with reddish in beween, background colour creme.
Unterwater macro shot of Hypselodoris zephyra in Lembeh (Indonesia). Brightly coloured nidiibranch with red gills and rhinophores, yellowish body with dark irregular lines and blue shades around.
Underwater ID shot of nudibranch: Nembrotha chamberlaini in Lembeh (Indonesia). Looking down at seaslug with white body with reddish brown patches, yellow-orange at base of gills and rhinophores.
Underwater macro shot of Goniobranchus aureopurpureus in Lembeh (Indonesia). The nudibranch sits on black sand. Its whitish body is covered in yellow dots and it has a blue irregular rim along the mantle. The rhinophores and gills have a red to purple or violet tint and are pushed to the left by the current.

All pictures are taken with my Olympus OM-D E-M1 Mark II and the Olympus M.60mm F2.8 Macro lens in a Nauticam housing and two strobes (Sea&Sea YS-01 and INON Z-330 until April 2019, from May 2019 2 x INON Z-330 ). I developed the photos in Adobe Lightroom 6.