Halgerda? found again

April 29, 2008
From: Colin Ogden

Dear Bill,
On 2nd July 2005, I found this Halgerda?(lower photo) which I thought might be a variation of the Halgerda wasinensis [see message #14189]. I have been trying to find it again for over 2 years and more than 1000 dives. At last I have found another one (upper photo). This was on a different reef, but with some similarities. Deeper than 24 metres, some scattered rocks on sand with sparse coral and sponges.

Locality: Sodwana Bay, 30 metres, South Africa, Indian Ocean, 04 September 2007, Sparse reef on sand. Length: 45mm. Photographer: Colin Ogden.

Unfortunately there was no feeding or any interesting activity taking place.
I still have not been able to identify it.
regards
Colin

scubaco@iafrica.com

Ogden C M, 2008 (Apr 29) Halgerda? found again. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/20670

Dear Colin,

Yes I did suggest this might be a variant of Halgerda wasinensis in your earlier message, but on reflection I think I am probably wrong. In H. wasinensis the yellow lined ridged form a reticulate pattern and the edge of the mantle is translucent white with black spots. In this mystery animal the yellow ridging is sparser and at right angles to the mantle edge, and there is a yellow border at the mantle edge.

In fact the species it seems closest to is the Western Australian species H. theobroma. I think it would be misleading to suggest it is a variant of any known species so I think I will label it Halgerda sp. 7 until a better solution turns up.

Best wishes,
Bill Rudman

Rudman, W.B., 2008 (Apr 29). Comment on Halgerda? found again by Colin Ogden. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/20670

Factsheet

Halgerda sp. 7