Johnson & Gosliner, 2001
Known only from Midway and Hawaiian Ids.
Midway Atoll. On pier pilings at 5 meters, 10 April 2000. Photo: Keoki Stender.
The animal is translucent with a pinkish purple tinge, and appears white from the colour of the internal organs. There is a thin submarginal reddish-pink to purple line around the mantle. There is a similar coloured submarginal line around the posterior part of the foot. Around the posterior end of the mantle there is a very distinctive opaque white band of mantle glands, and at the anterior end of the mantle, there are clusters of 3 or 4 similar glands at the edge of the mantle, on each side, in front of the rhinophores. The rhinophore clubs are translucent orange. The gills are translucent white at the base and the upper two-thirds is translucent orange.
In shape and colour Thorunna kahuna is very similar to Thorunna daniellae. According to Johnson & Gosliner (2001) "the most distinct external difference between T. daniellae and T. kahuna is the presence of large, visible mantle glands on the sides of the head anterior to the rhinophores and posterior to the gills in T. kahuna." If glands are present in T. daniellae they are not visible with the naked eye. Thorunna kahuna and T. daniellae also have different radular teeth, with those of T. kahuna having many more denticles than those of T. daniellae. Interestingly, the only two species of Thorunna with visible mantle glands, T. kahuna and T. australis also have very denticulated teeth. Another two differences between T. daniellae and T. kahuna concern the gills. In T. kahuna, the whole of the upper gill is suffused with orange while in T. daniellae, the orange pigment seems restricted to an orange line up the outer edge of the gills. Like most species of Thorunna, this species rhythmically vibrates its gills [see Keoki Stender's message].
• Johnson, R.F. & Gosliner, T.M. (2001) Two new species of Thorunna Bergh 1878 (Mollusca: Nudibranchia: Chromodorididae) from the Indo-Pacific. Bollettino Malacologico, 37(5-8): 143-150.
Rudman, W.B., 2003 (October 1) Thorunna kahuna Johnson & Gosliner, 2001. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/thorkahu
Re: Thorunna kahuna from Midway
From: Keoki Stender, October 5, 2003
Re: Thorunna daniellae from Midway
From: Keoki Stender, October 4, 2003
Thorunna kahuna and T. daniellae
From: Rebecca F. Johnson, October 4, 2003
Radula of Thorunna kahuna
From: Rebecca Johnson, October 4, 2003
Thorunna daniellae from Midway
From: Keoki Stender, October 1, 2003