Author: Undescribed

Order: Nudibranchia  Family: Chromodorididae

Maximum Size: 50 mm

Sightings: Sunshine Coast

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Ardeadoris sp. 01 Undescribed

We have placed this species in Ardeadoris on the basis of its external appearance:
– The elongate-oval mantle with significant overhang.
– The many folds to the mantle margin together with a distinctive large in-fold on each side halfway down the mantle length.
– The uncanny similarity of the gills to the distinctive gills of Ardeadoris egretta.

The mantle shape is elongate-oval, broadly overhanging the foot the tail of which can be seen protruding behind the posterior margin of the mantle. The long rhinophores can retract into protective pockets. The gills too can retract into a protective pocket. The gills have a distinctive appearance. Each gill is quite thin and elongate, tapering to a point. The gill is arranged in an arc around the anus, open posteriorly, and with each end of the arc forming an inward spiral. The gills moves continuously with a regular rhythmical motion when expanded.

The mantle is semitranslucent white. The very edge of the mantle carries a quite narrow opaque white band inside of which is a wide golden-yellow band, darkest laterally, and then a narrower vivid opaque white band. These are apparent both dorsally and ventrally. This series of coloured bands on the mantle edge are repeated on the margin of the foot and tail of the foot. The rhinophores are light orange in colour both stalk and club however the tip of the club is white. There are no vertical white lines up the rhinophores however we have recorded a specimen where the rhinophores are white with the faintest hint of a vertical orange line. The gills are translucent white but have opaque white pigment on the outer face. A faint trace of yellow pigment is visible at the very tip of each gill.

The diet is unknown but this species would be a spongivore.

Currently reported from Indonesia and southern Queensland, Australia.

David A. Mullins February 2022

References:
– Rudman, W. B., (1984) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: a review of the genera. Zoological Journal of the Linnean Society 81: 115-273.

– Rudman, W. B., (1985). The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Chromodoris aureomarginata, C. verrieri and C. fidelis colour groups. Zoological Journal of the Linnean Society 83: 241-299.

– Rudman, W. B., (1990). The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: further species of Glossodoris, Thorunna and the Chromodoris aureomarginata colour group. Zoological Journal of the Linnean Society, 100(3): 263-326.

– Coleman, N., (2008). Nudibranchs Encyclopedia. Neville Coleman’s Underwater Geographic Pty Ltd, Springwood, Qld.