Trapania circinata
Gosliner & Fahey, 2008

Suborder: DORIDINA
Family: Goniodorididae


Known only from the Marshall Islands.


Upper:  Legan Island, Kwajalein Atoll, 30m, Marshall Islands, Pacific, 13 August 2007, Crawling on sand. Length: 17mm. Photographer: Scott and Jeanette Johnson.  Lower: CASIZ 116803. Radular morphology. Scale =20 µm.[From Gosliner & Fahey 2008: Fig. 33C].

The body is translucent white and the oral tentacles and rhinophore clubs are black. The extra-rhinophoral processes and the much larger extra-branchial processes are translucent whitish with scattered back specks. The rhinophores stalks and the basal half of the gills are also translucent with black specks, while the upper half of the gills are edged with black. The sole animal was 10 mm long alive. 

Gosliner & Fahey mention the similarity in the radular morphology of T. circinata and T. naeva and in fact, apart from the absence of dark spots on the body, they would be difficult to distinguish from each other. In their description of T. circinata they describe the oral tentacles as white, but from their published photo the oral tentacles are clearly black [or dark brown]. From another of Scott Johnson's photos already on the Forum [#6326]  the white tentacles at the front are the tentacular foot corners not the oral tentacles. This animal has previously been considered a colour form of T. darvelli on the Forum but the radular morphology of the two species is quite different.

  • Gosliner, T.M. & Fahey, S.H. (2008)  Systematics of Trapania (Mollusca: Nudibranchia: Goniodorididae) with descriptions of 16 new species Systematics and Biodiversity, 6 (1): 53-98
Authorship details
Rudman, W.B., 2008 (March 13) Trapania circinata Gosliner & Fahey, 2008. [In] Sea Slug Forum. Australian Museum, Sydney. Available from

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  1. Re: Trapania darvelli? from the Marshalls
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