Author: (Audouin, 1826)

Order: Nudibranchia  Family: Tritoniidae

Maximum Size: 60 mm

Sightings: Sunshine Coast, Whitsundays

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Tritoniopsis elegans (Audouin, 1826)

Tritoniopsis elegans is a dendronotid nudibranch of the Tritoniidae family whose members possess uniquely shaped rhinophores. They arise out of raised sheaths that are usually scalloped or lobed on their rim. The rhinophore terminates in a club (in this case a long smooth finger) that is surrounded by a lower ring of vertical papillae looking much like a crown.

The most conspicuous feature of this species is its display of finely branched (lace-like) “cerata”, arranged down both sides of the mantle rim, that function as secondary gills. It is long (to 60 mm), broad, tapering to the pointed tail and deep in body. Colour is translucent white with opaque white marbled patterning on the smooth dorsum. It is sometimes tinted with orange or yellow. The aforementioned secondary gills are most often laid out horizontally, especially when feeding, but will curl up if aggravated. The oral veil too is elaborate, possessing a number of forward projecting sensory tentacles (velar tentacles) along the anterior margin. Tritoniopsis elegans feeds on a variety of soft corals including species of Lobophyton, Sinularia and Briareum and the resulting feeding scars on these corals may be an indication of their presence in the area. The spawn is white or yellow and laid on the substrate as a spiral. The counter-clockwise spiral is laid down in a zig-zag manner with discrete packets of eggs contained in a translucent jelly-like mucous. It is widely distributed in the Indo-West Pacific.

Originally described as Tritonia elegans.

Other synonyms include:
Tritoniopsis alba
Tritoniopsilla alba

References:
– Baba, K. (1969). Taxonomic study on Tritoniopsis elegans (Audouin, 1826) from Seto, Japan (Nudibranchia:Dendronotoidea). Publications of the Seto Marine Biological Laboratory. 16(6): 395-398.

– Yonow, N. (2017). Results of the Rumphius Biohistorical Expedition to Ambon (1990). Part 16. The Nudibranchia – Dendronotina, Arminina, Aeolidina, and Doridina (Mollusca: Gastropoda: Heterobranchia). Archiv für Molluskenkunde. 146(1): 135-172.

– This Species Profile has been modified from a previously published article in Dive Log Magazine’s – Critter ID with NudiNotes Column, Issue: #363 (October 2018):12 by David A. Mullins

David A. Mullins, July 2019