Actinocyclus papillatus
(Bergh, 1878)
Order: NUDIBRANCHIA
Suborder: DORIDINA
Superfamily: EUDORIDOIDEA
Family: Actinocyclidae
DISTRIBUTION
Tropical Indo-West Pacific
PHOTO
Upper: Coffs Harbour region, nothern New South Wales, December 1990. Photos: Bill Rudman [more detail to be added]. Lower: Seogwipo. Bum islet, Jeju. Sth Korea. Depth: 26 m. Length: Approx. 100 mm. July 2005. Muddy. Photographer: Sung Han Cho.
Until recently most specimens of Actinocyclus were identified as the single species Actinocyclus japonicus (Eliot, 1913) because of the difficulty in understanding earlier descriptions. Valdes (2002) reviewed the genus and has proposed we recognise two species, A. verrucosus and A. papillatus. The main synonym of A. papillatus is Sphaerodoris laevis var variegatus Eliot, 1904.
In general, the species of Actinocyclus have a tough leathery mantle, with a circlet of many short gills held in a cup-shaped arrangement similar to Hallaxa. In A. papillatus the body is covered with many large rounded tubercles. It ranges in colour depending on the shade of the brown background colour and the density of the cream white speckling scattered all over. Some animals are brown with little craemy speckling, while others are mainly cream white with only patches of the brown background colour showing through. In Valdes's review he describes 'a number of short, irregular, very densely arranged dark grey lines ...' and ' numerous white spots'. This is very dependent on how much white pigmentation is present in the specimen being observed. While the white spots are very obvious, the lines are only present in specimens with quite dense white pigmentation. This species grows to at least 10 cm in length.
-
Bergh, L. S. R. (1878) Malacologische Untersuchungen. In: C.G. Semper, Reisen im Archipel der Philippinen, Wissenschaftliche Resultate. Band 2, Heft 13: 547-601,Pls.62-65.
- Ehrenberg, C. G. (1828 or 1831) Symbolae physicae seu
icones et descriptiones animalium evertebratorum sepositis insectis quae ex itinere per Africam borealem et Asiam Occidentalem--novae aut illustratae redierunt. Decas 1 Mollusca. - Eliot, C. N. E. (1913) Japanese nudibranchs. Journal of the College of Science, Tokyo Imp. University, 35: 1-47. (Pls.1-2)
- Risbec, J. (1956) Nudibranches du Viet-Nam. Archives du Museum National d'Histoire Naturelle Paris, 7 4, 1-34. (Pls. 1-22)
- Valdés, A. (2002) Review of the genus Actinocyclus Ehrenberg, 1831 (Opisthobranchia: Doridoidea). The Veliger 45: 193-202.
Rudman, W.B., 2005 (August 4) Actinocyclus papillatus (Bergh, 1878). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/actipapi
Related messages
Actinocyclus papillatus from Hong Kong
March 1, 2007
From: Felix Poon
Dear Bill<
Is this a Dendrodoris denisoni? The slug is not very slug-shaped and has many blue "eyes". There are 2 pink rhinophore which are facing us.
Locality: Trio Island, 10 m, Hong Kong, Indopacific, 2 Oct 2006, On rock. Length: 13 cm. Photographer: Felix Poon.
Thanks
Felix Poon
ifex@hotmail.com
Poon, F., 2007 (Mar 1) Actinocyclus papillatus from Hong Kong. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/19531Dear Felix,
This is Actinocyclus papillatus, which sometimes sits in strange distorted shapes. I haven't seen one before with the dark spot at the tips of the tubercles looking so blue. The egg ribbon looks very like that of the other species of Actinocyclus, A. verrucosus [messages #14472; #262]
Best wishes,
Bill Rudman
Actinocyclus papillatus from eastern Australia [2]
August 10, 2005
From: Bill Rudman
Here is a photo of another specimen of Actinocyclus. It helps to illustarte the confusion that has existed over how many species there are in the genus. I would presume this is a a specimen of Actinocyclus papillatus with poorly developed papillae. You can clearly see the large crater-like pocket in which the gills sit. The gills themselves are aranged in the goblet-shaped arrangement typical of both Actinocyclus and Hallaxa.
Locality: Minnie Waters, nthn New South Wales, eastern Australia, 24 Mar 1971. AM C82050. Photo Judith Hunter
Bill Rudman
Rudman, W.B., 2005 (Aug 10) Actinocyclus papillatus from eastern Australia [2]. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14524Actinocyclus papillatus from eastern Australia [3]
August 10, 2005
From: Bill Rudman
Compared with the specimen from northern new Suth Wales [message #14524], this specimen of Actinocyclus papillatus from southern Queensland, is a more typical specimen, with quite large papillae and scattered opaque white specks.
Locality: Pt Vernon, Hervey Bay, sthn Queensland, Asutralia, under rock at low tide 23 Oct 1976. AM C105714. Photo: I. Loch.
Bill Rudman
billr@seaslugforum.net
Rudman, W.B., 2005 (Aug 10) Actinocyclus papillatus from eastern Australia [3]. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14525Actinocyclus papillatus from tropical eastern Australia
August 10, 2005
From: Bill Rudman
This pair of Actinocyclus papillatus could easily be mistaken for A. verrucosus. They are very smooth, the papillae being very low, especially in the pale smaller animal. However both animals show signs of the opaque white speckling found in Actinocyclus papillatus.
Locality: Bingil Bay, E. of El Arish, Nth Queensland. sth end of beach under stones at low tide.silted rocky shore 2 June 1977 AM C107822. Photo: P.H. Colman
Bill Rudman
Actinocyclus papillatus from Hong Kong [1]
August 10, 2005
From: Bill Rudman
Here is a photo of another Actinocyclus papillatus from Hong Kong. This one was taken by Brian Darvell.
Locality: Basalt Is, Hong Kong, 29 July 1984, 1896, Photo: B.W.Darvell AM C142949.
Bill Rudman
billr@seaslugforum.net
Actinocyclus papillatus from Hong Kong [2]
August 10, 2005
From: Bill Rudman
To show some of the variability in species of Actinocyclus here is a photo of Actinocyclus papillatus taken by Bernard Picton in Hong Kong. The close-up shows the darkened pit which can develop at the tip of the papillae.
Locality: Hong Kong workshop April 1983, no specimen. Photo: B.E.Picton, Locality:
Bill Rudman
billr@seaslugforum.net
Rudman, W.B., 2005 (Aug 10) Actinocyclus papillatus from Hong Kong [2]. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14477Actinocyclus papillatus - another from Sth Korea
August 5, 2005
From: Dong Bum Koh
Dear Bill,
This is another Lab. photo of Actinocyclus papillatus that was sampled several months ago at Bum islet in Jeju, Sth Korea..
From that time, it was kept in my friend's aquarium. I post dorsal & ventral views of this animal.
I will be happy, if this photo is helpful for your identification.
Best regards,
Dong Bum Koh
drkoh@seasee.co.kr
Dear Koh,
Thanks for this. As I said before, it seems that the degree of white pigmentation is very variable in this species so it is nice to have photos of a specimen from Sth Korea with heavy white pigmentation to supplement your earlier photo [#14465] of a specimen with almost no white.
Best wishes,
Bill Rudman
Actinocyclus species
August 4, 2005
From: Bill Rudman
Dong Bum Koh's message [# 14465] on Actinocyclus papillatus has caused me to a bit of house-keeping on the genus. I have prepared a Fact Sheet for that species and A. verrucosus. Like many others, I had previously placed them all in Actinocyclus japonicus, until they were reviewed. Thanks Angel for your review - sorry its taken me a while to react. I will be posting photos of two more specimens of A. papillatus from Hong Kong, in the next day or so.
Bill Rudman
billr@seaslugforum.net
Rudman, W.B., 2005 (Aug 4) Actinocyclus species. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14481Actinocyclus papillatus from Sth Korea
August 4, 2005
From: Dong Bum Koh
Dear Bill,
This is a photo of what I think is Actinocyclus papillatus (Bergh,1878) from South Korea. Could you please confirm this for me.
Locality: Seogwipo. Bum islet, Jeju. Sth Korea. Depth: 26 m. Length: Approx. 100 mm. July 2005. Muddy. Photographer: Sung Han Cho
Best regards,
Dong Bum Koh
drkoh@seasee.co.kr
Dear Koh,
Thanks for these photos. Actinocyclus is one of the groups on the Forum which I have been planning to reorganise when I have time. Your interesting photos have made me sort out the photos of Actinocyclus I already have on the Forum. Your animal certainly fits Valdes's (2002) description of A. papillatus but both your animal, and mine from southeastern Australia [#14473 ], have much less white pigmentation than described by Angel Valdes. Your specimen is very large, very like some of the large species of Dendrodoris, such as D. carbunculosa.
Best wishes,
Bill Rudman
Actinocyclus papillatus from eastern Australia
August 4, 2005
From: Bill Rudman
I previously had this species on the Forum as a form of Actinocyclus japonicus but following Valdes's (2002) review, I guess this should be identified as Actinocyclus papillatus.
Locality: Coffs Harbour region, nothern New South Wales, December 1990. Photos: Bill Rudman [more detail to be added]
It fits his description of that species in having a very tuberculate mantle. Valdes also describes 'a number of short, irregular, very densely arranged dark grey lines ...' and ' numerous white spots'. While the white spots are very obvious, the lines are not so clear. If you look carefully at the lower right close-up, the spots do appear to be arranged in lines, which gives the intervening space the appearance of dark lines. The photo in Valdes (2002) is of an animal with much more white pigmentation.
Best wishes
Bill Rudman
billr@seaslugforum.net
