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Eubranchus cf. mandapamensis is characterized by annulate rhinophores and some large inflated cerata which are are huge for the size of the animal. The cerata have two tiers of tubercles and a bulbous tip. The apices of the cerata are pinkish tranlucent, subapical is a greyish band followed by a diffuse violett band, followed by a mottled tan-greyish band. The body and the appendages are transparent greyish, covered with minute brownish spots and some larger white spots.
It differs from Eubranchus mandapamensis by the annulate rhinophores. The author Rao clearly describes and draws evenly spaced annulations on the rhinophores. In fact Rao erected a new genus for this species - Annulorhina - to recognise these ringed rhinophores.
This specimen has no inflated cerata, and its left rhinophore has incomplete annulae, the right rhinophore seems to be damaged, maybe it is incompletely regrown.
This is Eubranchus mandapamensis in IPN:
Gosliner, Terrence M., David W. Behrens & Ángel Valdés. 2008. Indo-Pacific Nudibranchs and Sea Slugs. Sea Challengers Natural History Books. Gig Harbor, Washington. 426pp. at page 354
let me quote:"Eubranchus rubropunctatus is a synonym."
NUDIPIXEL writes "Eubranchus mandapamensis (Rao, 1968) Also known as: Eubranchus rubropunctatus , Eubranchus madapanamensis"
Bill Rudman: writes:
"See discussion [message #22443] as to whether this is a synonym of Eubranchus mandapamensis."
Very similar in the colour pattern are:
Eubranchus mandapamensis which differs by the spaced annulations on the rhinophores and
Eubranchus rubropunctatus which has papillae scattered over the rhinophores and
Eubranchus cf. rubropunctatus which differs by the smooth rhinophores
let me quote Bill Rudman:"While it is possible that one species could have this degree of rhinophoral variability I can't think of an example. At this stage I suggest we take a conservative approach and keep the three rhinophore types separate until we know more about the anatomy and variability of this species or group of species."
I will keep the specimens with papillae scattered over the rhinophores as Eubranchus rubropunctatus, and if there turns up a specimen with spaced annulations on the rhinophores, I will post this as Eubranchus mandapamensis!
Many phantastic shots of Eubranchus rubropunctatus are at Jun Imamoto's website umiushi,
and one more picture of a specimen with annulate rhinophores is at the umiushi-zukan website without information on the location.
More information on Eubranchus rubropunctatus are on Bill Rudman's Sea-Slug Forum!
How to cite:
Köhler, E. (2019), published 25 March 2019, Eubranchus cf. mandapamensis (Rao, 1968)
available from https://www.Philippine-Sea-Slugs.com/Nudibranchia/Cladobranchia/Eubranchus_mandapamensis_cf.htm