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Dendronotus frondosus

(Ascanius, 1774)


Klas Malmberg Aquatilis Say hallo to the monster from Sweden... This Dendronotus frondosus measured 152 mm, have anyone seen a bigger one?

Message posted on NE Atlantic Nudibranchs on 10 Nov 2013
Tine Kinn Kvamme Dendronotus frondosus 35mm length, 22 meters dept. From Drøbak in the Oslo Fjord, Norway. Canon G12, internal flash +handheld torch

Gary Cobb The overall brownish body with white botches would tell me Dendronotus frondosus

Gary Cobb

Tine Kinn Kvamme Thanks Gary :)

Gary Cobb Glad to help!

George Brown Dendronotus frondosus. I haven't seen this colour morph before. How widespread is it? Maxwell Bank, Isle of Muck, Scotland. Depth 35 metres. Specimen about 75mm long.

Klas Malmberg Aquatilis I have photograped a similar color morph i Sweden, Kosteröarna, round 30 meters depth.

Brendan Oonk I have never seen this morph (in the Netherlands)

Message posted on NE Atlantic Nudibranchs on 14 Jul 2012
Nils Aukan White Dendronotus frondosus

Wil Yu What an amazing animal! Beautiful photo!

Evie Go & most of the nudi pics u posted are so different fr those i see here. They're sooo beautiful!

Nils Aukan Thank you, we have strange creatures here too!

Evie Go very beautiful creatures i would say! Just amazing!

Ashley Missen Now there is a New one for the Database and Site too -- Please Send Photo and Info to data@nudibase.com Cheers Ash

Nils Aukan Dendronotus frondosus, Brattøy,Kristiansund, 7-02-10

Ken Thongpila Wow! pretty cool nudis from different part of the world... Love it :-)

Mark Pidcoe Another first for me This may be a Dendronotus Frondosus, but the cirri is a closer match to the label on the photo it will not be the 1st time I got an ID wrong :)

David Ehecatl Carroll Please stop; you're making me miss California. ;-)

Marli Wakeling I think it may be D. subramosus.

Mark Pidcoe That was my other option, but this guy is so tiny, and i did not have a lot to work with the blade of surf grass it is on is only about 2.5mm in width, so i guess total size at about 10-12mm So Marli, you may be right

Marli Wakeling Or, it could be a juvie D. frondosus. I think the former guess is the case though.

Message posted on NUDIBRANCH LOVERS on 28 Oct 2013
Pascal Van Acker dendronotus frondosus Pen 1 14-42 lens

Message posted on NUDIBRANCH LOVERS on 10 Oct 2013
Ronni Bless Bekkemellem Dendronotus frondosus. Nikon D3200 (18-55vr lens with +5 diopter) F36, iso 100, 1/200sec

Message posted on UW photo - Fotosub on 13 Mar 2013
Lars Nedergaard Dendronotus Frondosus, Nikon D7000, Nikkor 105mm, 2 x Sea&Sea ys110alpha, 1/250, f20, iso 100

Message posted on Underwater Macro Photographers on 23 Apr 2012
Ronni Bless Bekkemellem Dendronotus frondosus. Nikon D3200 (18-55vr lens with +5 diopter) F36, iso 100, 1/200sec

Message posted on UWphotographers on 13 Mar 2013
Tine Kinn Kvamme Dendronotus frondosus 35mm length, 22 meters dept. From Drøbak in the Oslo Fjord, Norway. Canon G12, internal flash +handheld torch

Gary Cobb The overall brownish body with white botches would tell me Dendronotus frondosus

Gary Cobb

Tine Kinn Kvamme Thanks Gary :)

Gary Cobb Glad to help!

Erlendur Guðmundsson One taken today, the name in Icelandic is Skrautbjarki :)

Nils Aukan In latin, Dendronotus frondosus, normally big and white, approx 10. cm long. In norwegian "Busksnegl". Common as white in the winter. Small brown mottled in the spring, summer and autumn.Juveniles lay egs too.

Erlendur Guðmundsson I have never seen them white only with this color, and increasing in numbers in winter.

Erlendur Guðmundsson As all nudies in Iceland, increasing in numbers in winter.

Gisli Arnar Gudmundsson The shipyard is the place...

Erlendur Guðmundsson Taken yesterday in north of Iceland, depth 8 meters in 5°C.

Ken Thongpila Weird looking this one but hope get chance to see them one day.

Sarah Bowen Dendronotus frondosus if I'm not mistaken; we get these in the UK too. Great picture!

Erlendur Guðmundsson One taken today :)

Johny Leffelaer Lijkt wel Dendronotus frondosus,nice pic.;-)

Erling Svensen Bernard said something about nudies eating different food when juvenil and adult. Here are many Dendronotus frondosus on Obelia. They do not eat Obelia when adult?

Peter H van Bragt They do eat a variety of hydroids that may be available. However in Dutch coastal waters there is a distinct preference for Tubularia indivisa, if available. Feeding on this large solitary hydroid this nudibranch grows to a much larger size (12+ cm.) with also a much larger spawn than when feeding on other hydroids. An interesting form of ecophenotypical variation. As soon as T. indivisa is locally depleted by the predating nudi's they shift to other small hydroids. Cheers Peter H van Bragt

Bernard Picton I think that idea of ecophenotypical variation needs testing, Peter. It could be that we have several similar species here in Dendronotus.

Peter H van Bragt What we observe is that D. frondosus is year round present as relatively small indivuduals. In an annual reoccuring cycle we also see that when animals start feeding on T indivisa in winter, that animals solely feeding on T. indivisa tend to become extremely large. As soon as T. indivisa is depleted by predation the large ones have reproduced/spawned and only smaller individuals remain feeding on other hydroids. Outside the T. indivisa covered feeding grounds we do not find such extreme sized animals. Would you have access to DNA testing facilities??? I can provide specimen in early spring.

Lucas CerCur Erling, this is a very good question that shoud be tested bofore a reply.

Lucas CerCur I think that it is probable that changes in the diet of some opisthobrachs can happened. But I have not objetive data to confirme this.

Lucas CerCur Only some observations that could be use as departure hypothesis that should be tested.

Peter H van Bragt So, who can do the DNA work?????

Lucas CerCur What species you would like to sequence?

Peter H van Bragt Hi lucas, it's about Dendronotus frondosus: large specimen who feed on T indivisa and smaller ones who feed on other hydroids.

Lucas CerCur I'll try to reply later. I'm returning by train to home. OK?

Peter H van Bragt We're not in a rush ;-)

Cynthia D. Trowbridge From Sea Slug Forum: Robilliard, G. A. 1975. The nudibranch Dendronotus frondosus - one species or four? The Festivus (San Diego Shell Club), 6(8): 44-47.

Bernard Picton or ten?

Lucas CerCur I think that D. frondosus could be (or not) another case similar to Aeolidia papillosa.

Lucas CerCur In fact, in 1999 (I think) Mikael Thollesson published a paper in which replace the name D. lacteus as valid, when was considered as a junior synonym of the former.

Lucas CerCur So, in my view it is necessary to get (when possible) material from different localities of the theoretical distribution of the species, and then...start the sequencing.

Message posted on NE Atlantic Nudibranchs on 23 Jan 2013
Tine Kinn Kvamme Dendronotus frondosus. Drøbak, Norway. 25 mm at 5 meters dept.

Irine Ekimova It is Dendronotus lacteus, D. frondosus has the different pattern of branching ceratae

Tine Kinn Kvamme Thank you very much Irine Ekimova. I just thought it was a color variation, because I read they could be white as well.

Irine Ekimova Yes, they could be white, but the primary branches are not so long as in D. lacteus (see the photo, it is white specimen of D.frondosus from the Barents Sea). Also secondary and tertiary branches in D. lacteus are shorter and more pointed. But the best way you could distinguished them is the morphology of radula of course :)

Tine Kinn Kvamme I def see the difference between the two now. Thanks for enlightening me :-)

Tine Kinn Kvamme Irine, I just getting used to seeing nudibranchs here i Norway. I have most of my dives in Thailand. Do you know if any of the frondosus color variation are one in redish with yellow on the tips of the fringes?

Tine Kinn Kvamme ...or you would call the fringesa cerata?

Irine Ekimova Сolour variations of D. frondosus can be very diverse. They include all variations from white to yellow, brown or even reddish brown. But the problem is that some specimens of D. lacteus also could be brown or red. So the best way to distinguish them is to pay attention to the branching pattern of ceratae. In my MSc thesis I studied genus Dendronotus in Russian seas, so I have a lot of photos of these two species and others too. Unfortunately, the paper is just preparing now, but if you want I could share some photos and drawings with you :)

Nils Aukan Dendronotus frondosus + Polycera quadrilineata + Onchidiris muricata, all in one picture,by Kristiansund,North Sea.

Patrik Good Are these critters in their natural environment or is it a studio photo? Do they occur in this constellation (same food source) or did you put them together?

Nils Aukan These three nudibranchs are in their natural environment on top of a kelp frond. Not often three different nudis are that close, but in the spring,april and march we have hundreds of different nudis and many species all over the kelp and hydroid mats. I do NOT take pictures in a studio, only in their natural environment, and have done that since I started diving for 46 years ago, taking pictures from 1968.I only clean the pictures for some backscatter, and make the exposure in 1/250 sec. making black background. Also, I can give blue background with long exposure.

Nils Aukan On the kelp-fronds grow different hydroids and bryozoa. The young Dentronotus eat Obelia,Sertularia and Halecium hydroids. (The big grown-ups are white/yellow and prefer large tubularia.)The Onchidoris eat bryozoa,Membranipora membranocea, which also lives on the kelp. The Polycera quadrilineata eat the same.

Patrik Good Congratulations. Spectacular photos and background info. Your photos look so crisp and fresh. Thank you for sharing.

Carol Horne Any ideas re this little white nudi? Sound of Mull last Sunday.

David Kipling Dendronotus frondosus I think ...

Carol Horne I see what you mean, ie white with the merest sprinkling of spots - but it seems to lack the 'arborescent' gills mentioned in habitas?

David Kipling Yeah, but if you look closely (zoom in) bottom middle and also on the top edge there's the impression of some branching-ness on the lumps. They can pull them in.

Sarah Bowen Also I think he's a real baby, so they have probably not developed completely yet.

Carol Horne Ah, yes. I can see them. I did wonder if they could pull them in. Thanks David. Poor photo cos my camera controls were stuck and couldn't get macro. Next season will upgrade - or failing that get a strobe like those you showed me earlier this year. This will help until I can manage a better lens

Carol Horne Thanks Sarah...oh no, not juveniles...having enough trouble id'ing adults!!:-):-)

David Kipling Well there's Tritonia homberghii … as a juvenile it's while and lives on dead man's fingers, and as an adult it changes so much they thought it was a different species!

Carol Horne Aaargghhh!

Sarah Bowen You're not helping, David...

David Kipling Are you sure this isn't T homberghii var alba Sarah?

Sarah Bowen Stop it!

David Kipling No seriously, could it be?

Carol Horne It's rather like a tennis match.....aces all around! catch up with you guys next season:-)

Sarah Bowen Shame you can't see us sitting only a few feet apart on our respective laptops then! Yes, hope to make it up to North Wales again next year!

Brendan Oonk Can I offer an other sugestion: Dendronotus lacteus

David Kipling Argh!!!!!

Carol Horne Just looked it up...yes, a distinct possibility. The 'feel' of it somehow matches what I saw....not scientific I know, but ......

Fiona Crouch My first thought T. homberghii before I saw the debate between David and Sarah.

Carol Horne Oh dear......off I go to look this up...I'll never get to bed tonight...

Brendan Oonk http://www.nudibranch.org/Scottish%20Nudibranchs/html/dendronotus-lacteus-05.html

Carol Horne Yes!! Just looked pics of Tombergii juveniles. As far as I can see no red spots

Carol Horne Goodnight all....D lacteus wins at the moment.

David Kipling Habitat doesn't really help. If T homberghii should be sitting on a dead man's finger if white, if Dendronotus should be munching short hydroids. That being said, we did see plenty of white Dendronotus in the Firth or Lorn in Sept, and this was Mull.

Peter H van Bragt have a close look look at the tip og

Peter H van Bragt of the rhinophoral sheath on the right side. Not very sharp but the split that you can see is highly indicative for T. hombergii

Message posted on Seasearch Identifications on 08 Nov 2013
Erling Svensen Bernard asked me to post this one. Very, very tiny, only 3 millimeter long. He do not think its an exiguus, but what then?

Brendan Oonk I agree that it is not E. exiguus, because of the dubble swelling of each ceras, but can't id thid one

Egidio Trainito Looks like a juvenile E.doriae

Bernard Picton Thanks, Egidio Trainito, I agree. I'm just a bit surprised to see it here in Norway as I thought it was a southern species in the UK.

Egidio Trainito there's a lot to be discovered, I've learned...

Peter H van Bragt Could this be a juvenile Dendronothus frondosus. If I don't forget I'll post an even smaller one on this site on sunday!

Peter H van Bragt But Eubranchus doriae is of course also a good or might even be a better option ;-)

Helgi Winther Olsen I have seen quite a few juvenile E. frondosus at both Gulen and in the Faroes and do not think this resembles any of them. The cerate in them are much more "diffuse" or less developed, so to say. I will post a few juvenile E. frondosus photos (and then you may correct me, if the are not juvenile E. f. ;o) )

Christian Skauge This is Eubranchus doriae, which is now officially on the Norwegian species list :-)

Bernard Picton Peter H van Bragt, Torkild Bakken gave us a presentation on some CO1 barcoding results which indicate that Dendronotus frondosus is not a single species, at least in Norway. It would be a good idea to look closely at the morphology and pigmentation of any in your area. I've certainly noticed small differences in the past and had my suspicions...

Brendan Oonk Thanks for the info Bernard. Did the different types/species in norway have a clear difference in pigmentation/morphology?

Bernard Picton Brendan, they were all identified as Dendronotus frondosus and as far as I know had no distinctive differences. I suspect that there are several species which each come in a variety of pigmentation. It will be fruitful to look for ones which mature at different sizes and to look carefully at the branching of the ceratal processes I think. If we can identify several forms then they can be tested against the DNA sequences.

Brendan Oonk I will check our foto archive and keep this in mind when diving this year. I know Peter van Bragt contributes the size difference (mostly) to the food source.

Message posted on NE Atlantic Nudibranchs on 13 Mar 2013
Erling Svensen Bernard said something about nudies eating different food when juvenil and adult. Here are many Dendronotus frondosus on Obelia. They do not eat Obelia when adult?

Peter H van Bragt They do eat a variety of hydroids that may be available. However in Dutch coastal waters there is a distinct preference for Tubularia indivisa, if available. Feeding on this large solitary hydroid this nudibranch grows to a much larger size (12+ cm.) with also a much larger spawn than when feeding on other hydroids. An interesting form of ecophenotypical variation. As soon as T. indivisa is locally depleted by the predating nudi's they shift to other small hydroids. Cheers Peter H van Bragt

Bernard Picton I think that idea of ecophenotypical variation needs testing, Peter. It could be that we have several similar species here in Dendronotus.

Peter H van Bragt What we observe is that D. frondosus is year round present as relatively small indivuduals. In an annual reoccuring cycle we also see that when animals start feeding on T indivisa in winter, that animals solely feeding on T. indivisa tend to become extremely large. As soon as T. indivisa is depleted by predation the large ones have reproduced/spawned and only smaller individuals remain feeding on other hydroids. Outside the T. indivisa covered feeding grounds we do not find such extreme sized animals. Would you have access to DNA testing facilities??? I can provide specimen in early spring.

Lucas CerCur Erling, this is a very good question that shoud be tested bofore a reply.

Lucas CerCur I think that it is probable that changes in the diet of some opisthobrachs can happened. But I have not objetive data to confirme this.

Lucas CerCur Only some observations that could be use as departure hypothesis that should be tested.

Peter H van Bragt So, who can do the DNA work?????

Lucas CerCur What species you would like to sequence?

Peter H van Bragt Hi lucas, it's about Dendronotus frondosus: large specimen who feed on T indivisa and smaller ones who feed on other hydroids.

Lucas CerCur I'll try to reply later. I'm returning by train to home. OK?

Peter H van Bragt We're not in a rush ;-)

Cynthia D. Trowbridge From Sea Slug Forum: Robilliard, G. A. 1975. The nudibranch Dendronotus frondosus - one species or four? The Festivus (San Diego Shell Club), 6(8): 44-47.

Bernard Picton or ten?

Lucas CerCur I think that D. frondosus could be (or not) another case similar to Aeolidia papillosa.

Lucas CerCur In fact, in 1999 (I think) Mikael Thollesson published a paper in which replace the name D. lacteus as valid, when was considered as a junior synonym of the former.

Lucas CerCur So, in my view it is necessary to get (when possible) material from different localities of the theoretical distribution of the species, and then...start the sequencing.

Message posted on NE Atlantic Nudibranchs on 23 Jan 2013
Godfried van Moorsel Polycera quadrilineata - Burghsluis Oosterschelde NL another uninvited guest: who's hugging my tail?

Brendan Oonk Could it be a very small Dendronotus frondosus?

Godfried van Moorsel got it!

Message posted on NE Atlantic Nudibranchs on 02 May 2012
James Lynott Are these Dendronotus frondosus? They were found on a dive in Loch Leven at between 20-25m depth on sheltered rocky/boulder slope.

Brendan Oonk I would say so

James Lynott Thanks Brendan Oonk

Bernard Picton We have a cryptic species situation with Dendronotus frondosus in the NE Atlantic. Preliminary sequencing results from Norway indicate three or four species which are currently being included in D. frondosus. My gut feeling is that this is right as I've noticed several varieties myself.

James Lynott That is interesting. I have also seen a few varieties (before I got my camera unfortunately) which is why I was a bit unsure as to whether these individuals were in fact D. frondosus.

Message posted on NE Atlantic Nudibranchs on 16 Sep 2013
Tony Gilbert I reckon its a tiny Dendronotus frondosus, around 6-7mm. https://www.facebook.com/media/set/?set=a.173485702785521.38902.100003722780643&type=1#!/photo.php?fbid=190510057749752&set=a.173485702785521.38902.100003722780643&type=3&theater

Brendan Oonk Hi Tony

Brendan Oonk What I tried to say: Hi Tony, the egss look like D. frondosus

Brendan Oonk Can't find the nudi that should be in this pic

Tony Gilbert If it is a nudi, its to the left of the top of the eggs.

Message posted on NE Atlantic Nudibranchs on 22 Sep 2012
Avril Keith i dont have a clue what this is, but i found loads of them on the rocks at the farne islands last weekend.

David Kipling Dendronotus frondotus. It eats kelp fir, hence why it's on kelp. Very cute species !

Avril Keith wow thanks..can you recommend me a reference book on nudis? ive only got paul naylors book and it only touches on them.

David Kipling Bernard Picton's field guide (out of print, hunt it down on eBay or abebooks).

Avril Keith thankyou so much x

George Brown Or Bernard's website http://www.habitas.org.uk/marinelife/index.html

Jane Wilkinson Picton's nudibranch book is like golddust Avril and if you're lucky enough to find one you'll have to pay a fortune for it! Try Jim Anderson's site Scottish Nudibranchs. You'll find practically everything you need on there. Nice pic by the way.

Craig Muirhead Try http://www.habitas.org.uk/marinelife/

Avril Keith ive been on ebay and amazon and seems none...lol but a link says that book might be reprinted...

Craig Muirhead The mollusca section is basically Bernard's book in digital format.

Craig Muirhead Jim's site is very good too of course :)

Jane Wilkinson I think he'd be glad that you added that comment :D You being his dive buddy an all.

Laura Shearer This species is fairly common around here but stunning little individual there- nice pic!!!

Avril Keith i havent been lucky with spotting nudibrancs in my last year of diving and i was over whelmed by them in the farnes :) it was amazing to see so many

Laura Shearer They are numerous around the Farnes and nice variety of species :) good vis certainly helps too!!

Bernard Picton Avril, were all of the Dendronotus you saw at the Farnes this colour? We had large numbers near Oban three weeks ago, mostly white but a few like this. We know that Dendronotus lacteus is a different species, but I think it may come in red, brown and white forms.

David Kipling Are you suggesting the white ones are adapted to lived in the dark abyssal depths, only to be preyed upon by the lone B. pictonesis with its specialised MgCl2-containing venom gland?

Avril Keith Yes they were all red x

George Brown Hey! He wasn't entirely alone!

Bernard Picton I did spend considerable time in the kelp, Dawn. Had to decompress somewhere....

Jane Wilkinson Also red ones at Loch Carron a month ago

Bernard Picton If you want the text for the book it is here: http://www.seaslug.org.uk/nudibranchs/

David Kipling You don't get out of doing a reprint *that* easy, Bernard ...

Jane Wilkinson We'd all like a reprint Bernard! Frustrating miles from anywhere with no signal trying to ID stuff.

Bernard Picton I should point out to you that we know that Dendronotus frondosus is not a single species, but at least 4 in Norway. So sets of photos of animals which make up a single population are useful to try and pin down variation within these cryptic species.

Bernard Picton Reprint - yes, working on it. I'd like it to stand the test of the next 20 years, so needs some names for some undescribed Doto and probably several other cryptic species. We now know that even the common grey seaslug, Aeolidia papillosa, is two species in the NE Atlantic..

Message posted on NE Atlantic Nudibranchs on 29 Sep 2013
James Lynott Are these Dendronotus frondosus? They were found on a dive in Loch Leven at between 20-25m depth on sheltered rocky/boulder slope.

Brendan Oonk I would say so

James Lynott Thanks Brendan Oonk

Bernard Picton We have a cryptic species situation with Dendronotus frondosus in the NE Atlantic. Preliminary sequencing results from Norway indicate three or four species which are currently being included in D. frondosus. My gut feeling is that this is right as I've noticed several varieties myself.

James Lynott That is interesting. I have also seen a few varieties (before I got my camera unfortunately) which is why I was a bit unsure as to whether these individuals were in fact D. frondosus.

Message posted on NE Atlantic Nudibranchs on 16 Sep 2013
Brendan Oonk

David Fenwick Snr That's very well spotted and a brilliant image considering the size of the animal.

Brendan Oonk Thanks David, the photo was taken by Floor.

Helgi Winther Olsen I've just poste an album with different findings of juvenile Dendronotus frondosus: https://www.facebook.com/photo.php?fbid=10151345183227960&set=oa.357800997664520&type=1&relevant_count=8&ref=nf

Kevin Sinclair Yikes! is that sub 5mm?

Brendan Oonk Yes, less than 2mm

Message posted on NE Atlantic Nudibranchs on 15 Mar 2013
Taxonomy
Animalia (Kingdom)
  Mollusca (Phylum)
    Gastropoda (Class)
      Heterobranchia (Subclass)
        Opisthobranchia (Infraclass)
          Nudibranchia (Order)
            Dexiarchia (Suborder)
              Dendronotida (Infraorder)
                Tritonioidea (Superfamily)
                  Dendronotidae (Family)
                    Dendronotus (Genus)
                      Dendronotus frondosus (Species)
Associated Species