Protector Reef, Red Sea, off Sudan, 45mm long crawling. May 12,1995. Depth: 8 meters. Photos: Mary Jane Adams.
Described from the Red Sea, this species has close similarities in colour to a group of western Pacific species, including Nembrotha rutilans. It is reported to swim by lateral flexion when disturbed.
• Yonow, N. (1990) Red Sea Opisthobranchia 3: The orders Sacoglossa, Cephalaspidea, and Nudibranchia: Doridacea (Mollusca, Opisthobranchia). Fauna of Saudi Arabia, 11: 286-299.
Rudman, W.B., 2000 (August 3) Nembrotha megalocera Yonow, 1990. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/nembmega
December 10, 2009
From: Django Manglunki
I believe this is a Nembrotha megalocera. I saw it during our very last, shallow dive at the end of a diving cruise in the Red Sea. Video footage available at
Locality: Abu Ramada, 11 m , Egypt, Red Sea, 06 November 2009, sandy bottom. Length: about 30 mm. Photographer: Django Manglunki.
email@example.comManglunki, D., 2009 (Dec 10) Nembrotha megalocera crawling on sandy bottom. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22909
Thanks for the photos. It is good to get another record of this species which seems to be confined to the Red Sea.
March 5, 2008
From: Jaco Vreugdenhil
Concerning message #21267:
Two more photo's of Nembrotha megalocera mating.
I have a short movie also.
Locality: Dolphin House Reef, About 12 meters, Near El Goua (Hurgada Area), Red Sea, 29 september 2007. Length: Both about 10-12 cm. Photographer: Jaco Vreugdenhil.
firstname.lastname@example.orgVreugdenhil, J, 2008 (Mar 5) Re: Nembrotha megalocera mating - Red Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21412
February 15, 2008
From: Annette Kliphuis
When diving in the Red Sea last week we finally encountered some nudi's on one (and the only) dive at Samadai reef. These two Nembrotha megalocera seem to be mating! I couldn't find a picture of this on the forum yet, so I hope you find this a useful contribution.
Locality: Samadai reef (west), Marsa Alam, 10m, Egypt, Red Sea, 26 November 2007, Hard coral (some soft coral) garden, sandy bottom in between. . Photographer: Marieke Koopmans.
Thanks for the forum, I find it very nice to read and find all the information about nudi's!
Annette.Kliphuis@wur.nlKliphuis, A.M.J., 2008 (Feb 15) Nembrotha megalocera mating - Red Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21267
Glad you like the Forum and thanks for the photo of this species mating. It is nice to be able to compare it with photos of the similarly coloured N. rutilans mating [message #18775 ]. As I have said before, we don't know how important such details are in distinguishing species, but the only way to find out is to build up some information, and this is a good way to do it.
August 25, 2006
From: Joseph De Vroe
Is this Nembrotha megalocera ready for mating ?
Locality: Saqwa (Galawa), 10m, El Gouna, Egypt, Red Sea, 21 July 2006, sandy. Length: 8cm. Photographer: Joe De Vroe.
Joe De Vroe
email@example.comDe Vroe, J., 2006 (Aug 25) Nembrotha megalocera ready for mating ?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/17492
You quite often find a nudibranch with the genital aperture slightly swollen like in your photo. Usually it is a response to meeting another animal of the same species, but sometimes it can be a prelude to egg-laying.
May 3, 2006
From: Jamie Malone
Saw these guys on a dive in the red sea last year never could find a name in any guide book for him
Locality: Marsa Alam, 35 meters, Egypt, Red sea , 15 May 2005, a drop off , 30 meter vis, 27 degree water temp. Length: 50 mm. Photographer: Jamie Malone .
firstname.lastname@example.orgMalone, J., 2006 (May 3) Nembrotha megalocera from the Red Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/16503
This is Nembrotha megalocera. It seems to be quite common in the Red Sea
February 11, 2006
From: Umut Tural
Dear Bill Rudman,
I would like to share the most beautiful slug, I've ever seen, amazing color and elegant gills & rhinophores are like alien . I think this is a Nembrotha megalocera, if I'm wrong, please correct me. Thanks a lot.
Locality: Erg Abu ramada, Hurghada, 17, Egypt, Red sea, 11 January 2006
Length: 40 mm. Photographer: Dergun Tansel
Umut Tural, 2006 (Feb 11) Nembrotha megalocera from Red Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15769
No matter how many times you see photos of these animals it is never quite the same as seeing them alive. Yes this is Nembrotha megalocera.
November 2, 2005
From: Joseph De Vroe
Is it possible that this Nembrotha megalocera was laying her eggs ? I didn't notice it when I took the picture.
Locality: Saqwa (El Gouna), Egypt. Red Sea. Depth: 08 m. Length: ± 8 cm. 20 October 2005. sandy bottom. Photographer: Joe DE VROE
Thanks for your comments.
email@example.comDe Vroe, J., 2005 (Nov 2) Nembrotha megalocera laying eggs ?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/15106
It certainly looks like it is egg-laying. Unfortunately we would need a photo from the right side, where the reproductive openings are to be 100% sure
July 20, 2005
From: Kamal El Tawil
I would like to share with you some pictures i have recently taken in the Egyptian Red Sea. I found this Nembrotha megalocera creeping slowly on the reef. at one point, it seemed to have jumped from a part of the reef to another turning upside down. Is it true that this species is endemic to the Red Sea ?
Locality: Abu Dabab reef, Marsa Alam, Egypt, Red Sea. Depth: 9 metres. Length: approx 7-8 cms. June 24th, 2005. Photographer: Kamal El Tawil
Kamal El Tawil
El Tawil, K., 2005 (Jul 20) Nembrotha megalocera from the Red Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14198
Thanks for these photos which show the colour pattern very clearly. At present we only have records of theis colour pattern from the Red Sea. What we still have to work out is whether some of the other very similarly coloured species from other parts of the Indian and Pacific Oceans are different species, or colour forms of one or perhaps just a few species. Photos we are accumulating on the Forum should be very helpful
January 8, 2004
From: Valérie Grando
Here are some pictures of Nembrotha megalocera that I shot at Wadi Lahami, in the South of the Red Sea off Sudan on June, 2003.
I find the picture of the one "standing up" funny
Grando, V., 2004 (Jan 8) Nembrotha megalocera - 'sniffing around'. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/11752
Nudibranchs 'standing up' like this remind me of the Nth American 'Prairie Dog' [Cynomys spp] which stand upright like this when on guard duty. In a way they are doing exactly the same thing - checking out their neighbourhood. The difference is that the Prairie Dogs are looking for potential danger while the nudibranchs are 'smelling' for potential food organisms. By raising their rhinophores and moving them around they can pick up chemical signals - from their food - in the water and get an idea of where the chemicals have come from.
May 21, 2003
From: Ilan Ben Tov
This Nembrotha megalocera is from Ras Ghoslani in the Sinai Red Sea. It was taken in April 2003. Depth 15m. Estimated size is 30mm.
firstname.lastname@example.orgTov, I.B., 2003 (May 21) Nembrotha megalocera from Sinai. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9774
April 18, 2002
From: Marina Poddubetskaia
Here is another nudibranch I photographed at the end of March in Egypt. It was a dive cruise at the North of Red Sea, between Hurghada and Sinai mountains. All the joined photos come from there. Could you confirm that it is Nembrotha megalocera.
Data: about 10-12cm, 22 March 2002, "Manta Point" / North Red Sea, 11m depth
Nembrotha is my favourite genus (cf. Nembro) and this species is beautiful. I saw it (2 individuals) only at this site and it was my last dive. What a gift !
email@example.comPoddubetskaia, Marina. , 2002 (Apr 18) Nembrotha megalocera from the Red Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/6725
Yes this is what we call Nembrotha megalocera, but as you will see if you look through the messages on this page, there are a number of very similarly coloured species in the Indo-West Pacific and at present we are not sure just how many species there really are. Every new record is a useful piece of information.
August 4, 2000
From: Mary Jane Adams
Here are some pictures of Nembrotha megalocera that I shot on Protector Reef in the Red Sea off Sudan on May 12, 1995. This beautiful slug was crawling rapidly across the bottom. When it came to the yellow coral it stopped and began to feed on the polyps. At the time I thought it was eating the polyps, but from what I have learned on the Forum, it may have been slurping up flatworms from them. It reared up frequently while it was feeding, perhaps as an attack posture or in reaction to polyp stings? The polyps reacted by retracting in the area where it was feeding.
Depth: 8 meters
Crawling length: 45 mm
Dear Mary Jane,
Thanks for the great photos. Your observations on what it did when it got to the coral colony are interesting because species of Nembrotha are supposed to feed on ascidians. It is possible that your animal, crawling along, just ran into an obstacle that it found too difficult to crawl over. The region around the mouth, and its oral tentacles, are brimming with nerve endings, for this is how it learns about its close environment. Without sight, it can only find out how big an obstacle in its path is by feeling around with its mouth and oral tentacles. Eventually, I would assume, it would give up these feeling, rather than feeding movements, and try moving in another direction, in attempt to avoid the obstacle, in this case a coral colony.
Alternatively you could be quite right, which would be a very exciting discovery.