Known from the western Pacific Ocean (Micronesia, Papua New Guinea and Fiji)
14 m depth, Ponape, 21 Aug. 1985, dorsal view of 43 mm specimen, Photo: C. Carlson & P. Hoff (Brunckhorst, 1993: Plate 3 D).
Notes compiled from Brunckhorst, 1993:
Phyllidia carlsonhoffi is characterised by alternating large conical and small rounded tubercles (not joined as ridges), long, rounded oral tentacles, and a median black line on the foot sole. Phyllidia varicosa, Phyllidia elegans and Phyllidia tula each have a median black line on the foot sole. Phyllidia varicosa and P. elegans possess notal ridges and compound tubercles (P. carlsonhoffi has neither) and are blue-grey and pink respectively. Phyllidia tula appears to be similar to P. carlsonhoffi, but differs in a number of features. Ventrally, P. tula is always dark grey whereas P. carlsonhoffi is paler in colour. The oral tentacles are triangular in P. tula, whereas they are long and cylindrical in P. carlsonhoffi. Dorsally, P. tula is more tuberculate with a graduated series of tubercles which decreases in size from very large in the centre to tiny and closely packed at the margin. The tubercles of P. carlsonhoffi are evenly spaced with alternating large and small tubercles. Phyllidia madangensis is very similar to P. carlsonhoffi dorsally, however the former lacks alternating smaller tubercles, its larger tubercles are sparsely scattered, and it lacks markings on both the foot sole.
• Brunckhorst, D.J. (1993) The systematics and phylogeny of Phyllidiid Nudibranchs (Doridoidea). Records of the Australian Museum, Supplement 16: 1-107.
Rudman, W.B., 1999 (January 12) Phyllidia carlsonhoffi Brunckhorst, 1993. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/phylcarl
June 8, 2007
From: Harry B. Blalock
I have been running across several of these nudibranch recently, but they don't seem to match up to anything I've been able to find online. They are similar to a Phyllidia varicosa, and yet distinctly different. Could you help me ID them?
Locality: Wing Beach, 40', Saipan, Northern Mariana Islands, Pacific, 28 May 2007, crawling along rocks. Length: 1". Photographer: Harry Blalock.
Harry Blalock, 2007 (Jun 8) Phyllidia carlsonhoffi from Northern Mariana Islands. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19960
This is a species of Phyllidia, but not P. varicosa. Very appropriately these animals are Phyllidia carlsonhoffi named in honour of Clay Carlson and Patty-Jo Hoff who have studied the opisthobranchs of that very region for many years. The small tubercles interspersed between the large ones, are considered a way of distinguishing this species from P. madangensis.
June 5, 2007
From: Binyamin Koretz
Concerning message #19905:
On a recent trip to Micronesia we encountered what we assume, based on information from the Forum, to be Phyllidia carlsonhoffi. We saw it only once in Palau (at the southern island of Pelelieu) but very frequently in Yap, where we saw it at most sites on the outer reef.
The pair together was just breaking up, I'm afraid we missed the mating, if it took place.
Locality: Peleliu Wall, Palau; Barge Reef (the pair) and Vertigo Wall, Yap, 8-15m, Rep. of Palau and Federated States of Micronesia, Pacific Ocean, 27 Nov 2006 (Peleliu), 5 Dec 2006 (Vertigo), 8 Dec 2006 (Barge), coral reef. Length: 15-25 mm. Photographer: Binyamin Koretz.
email@example.comKoretz, B., 2007 (Jun 5) Phyllidia carlsonhoffi from Palau and Yap, FSM. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19946
Thanks for these interesting shots. It's not easy to distinguish P. carlsonhoffi and P. madangensis from the dorsal surface so when I saw your upper photo I was pleased to see the characteristic small tubercles alternating with the big tubercles, which is one character of P. carlsonhoffi separating it from P. madangensis according to Brunckhorst. Unfortunately the second animal has only one or two of these small tubercles. However P. madangensis is said to also have a small tubercle in front of each rhinophore and to have the large tubercles more sparsely spaced than P. carlsonhoffi so I think we can say your animals are both P. carlsonhoffi as you have identified them. One apparently good difference is that in P. carlsonhoffi there is a black median line on the sole of the foot which is absent in P. madangensis.
Another interesting point is that your animals are on an orange sponge. We have a growing number of photos on the Forum of phyllidiids on similar orange sponges. Brunckhorst records a number of species feeding on orange sponges of the order Axinellida, so although I can't identify the sponges from the photos, if we continue to get more records of these animals on similar sponges, it would certainly suggest that it would be a useful research project to investigate feeding specificity in the phyllidiids
May 23, 2007
From: Carrie Lo
Concerning message #18654:
My buddy took this photo in Derawan. I didn't see it myself and therefore has no idea on its size. Probably at about 15 m water. I guess it may be Phyllidia madangensis. Is that right?
Locality: Site: Coral Canyon, Derawan, 15m, Indonesia, 22 April 2007. Photographer: Pong Lai.
firstname.lastname@example.orgLo, C., 2007 (May 23) Phyllidia carlsonhoffi in Derawan, Indonesia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19905
There are two species which look quite similar, P. madangensis and P. carlsonhoffi. The most obvious external difference is unfortunately on the sole of the foot - P. carlsonhoffi having a median black line and P. madangensis not. There are more subtle dorsal differences with P. madangensis having a small white spot or tubercle right in front of each rhinophore, which is absent in your animal. Also the tubercles seem to be a bit more ovate in P. carlsonhoffi and rounded in P. madangensis. On balance I think your animal is P. carlsonhoffi although I have not seen an example of either species in which the median tubercles are joined in a ridge as in your animal.
April 28, 2006
I have a photograph of a mystery critter I found while diving in Fakarava. He is beautiful, but I'm not sure what he is. After extensive googles on black with orange spots which are outlined in white, I found he possibly is a Scutus. He may have ?red? antennae. He is about an inch, oblong, black with orange nubbins encircled in white. I did not see a shell of any sort. Thanks in advance!
Locality: Fakarava, 40 feet, French Polynesia, Pacific, 27 March 2006. Length: 1.5 inches. Photographer: Myself.
email@example.comLaurel, 2006 (Apr 28) Phyllidia carlsonhoffi from French Polynesia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/16461
Although the colours are very orange, I am pretty sure this is Phyllidia carlsonhoffi.
September 23, 2005
From: Judy Foester
This definitely shows the fried eggs that gave the nudibranch, Phyllidia varicosa, its common name!
Locality: Reef, Three Island Harbor, Albatross Pass, near New Hanover Island in Papua New Guinea, sandy bottom at this spot. Depth: 20 m [ 60 ft.]. Length: 55 mm. 26 May 2002. Photographer: Judy Foester
firstname.lastname@example.orgFoester, J.E., 2005 (Sep 23) Phyllidia carlsonhoffi from Papua New Guinea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14803
It may have a 'fried egg' pattern, but it is not Phyllidia varicosa. If you are a regular visitor to the Forum you will have noted that I am not a believer in making up common names for sea slugs. I don't know who made up the name 'fried egg nudibranch' for P. varicosa, but it is not a commonly used name, and only in some specimens of P. varicosa could the colour pattern be described as 'fried egg-like'. There are certainly other species of phyllidiid with a much better 'fried egg pattern' such as this species, which is Phyllidia carlsonhoffi, or the very similar looking Phyllidia madangensis.
Phyllidia carlsonhoffi is characterised by the black background to its mantle and the large rounded, yellow-tipped, white tubercles, which are interspersed with small tubercles. It also has a black median line on the sole of the foot. Phyllidia madangensis, in comparison, does not have interspersed small tubercles, lacks a black line on the sole of the foot, and has a small white tubercle just anterior to each rhinophore pocket. It is nice to get a photo of P. carlsonhoffi showing its features so clearly.
February 4, 2003
From: Danny Van Belle
Here's a nudi I filmed at about 10m depth at Nuku Hiva, Marquesas Islands on 15 August 2000. Divesite: Okue
Can you put the name on it ?
Van Belle, D., 2003 (Feb 4) Phyllidia carlsonhoffi from Marquesas Ids. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9068
Yes this is Phyllidia carlsonhoffi. There is a very similar looking species, Phyllidia madagensis but the best way to tell them apart, if you can see the front end of the animal, is to see if there is a small whitish tubercle on the anterior edge of each rhinophore pocket. Phyllidia madagensis has one and Phyllidia carlsonhoffi does not.
February 4, 2003
From: Danny Van Belle
To accompany my other message, here is the same phyllidiid, but from a different divesite at Nuku Hiva, Marquesas Islands.
Divesite: hammerhead sentinnel,
Date: August 2000.
Danny Van Belle
email@example.comVan Belle, D., 2003 (Feb 4) Phyllidia carlsonhoffi from Marquesas Ids (2). [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/9069
Yes this is also Phyllidia carlsonhoffi
July 23, 2000
From: Mary Jane Adams
Here is the Phyllidia I photographed on the The New England Aquarium-Nai'a expedition to the Phoenix Islands.
It is difficult for me to figure out. I found it at 20 meters on the lee side of Canton (Aba-Riringa) Island on July 2, 2000. It was 33 mm long. It looks most like the Phyllidia madangensis on your website, however, it has a broken dark median line on it's ventral side. The water temp on both islands was 83 degrees.
[The Phoenix Ids are in the central Pacific, approx 1000k north of Samoa]
firstname.lastname@example.orgAdams, M.J., 2000 (Jul 23) Phyllidia carlsonhoffi from Phoenix Id. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2762
Dear Mary Jane,
This is another interesting find. It has similarities to two species described by Brunckhorst, Phyllidia carlsonhoffi and Phyllidia madangensis. Both are described as having cream or white tubercles with yellow tips. Your photos clearly help to expand the definition of at least one of those species to bluish tubercles. Externally there seem to be two quite distinctive differences. In P. madangensis there is a small white tubercle on the front edge of each rhinophore pocket, not directly in front of the rhinophore but situated towards the midline of the body. The other difference is that the sole of the foot does not have a dark median line. In comparison, Phyllidia carlsonhoffi does not have a tubercle in front of each rhinophore and does have a dark median line on the sole of the foot. It is also described as having small white tubercles alternating with the larger coloured ones.
Your photos match Phyllidia carlsonhoffi very well. All we need to do is modify Brunckhorst's definition of the species to include bluish tubercles.
Another very useful bit of new information.