Halgerda dichromis Fahey and Gosliner, 1999

The name dichromis was given to this species to distinguish it from other Halgerda species that only have one color on the ridges. Halgerda dichromis has both black and orange coloration along the ridges. Gosliner in 1987 misidentified this animal as Halgerda formosa. But on further examination of specimens of both H. formosa and H. dichromis, and comparison to the original 1880 and 1888 descriptions of H. formosa, it became evident that we had a new species. Besides the external color differences between the two species, there are reproductive and radular differences.

This animal was collected the entrance to Durban Harbor, Natal, South Africa in 5 m water by Bill Liltved.

It sure would be nice if someone in South Africa would find another couple of these and send them over to us for examination! Photos of the specimens would be good to have sent with the animals too!


Shireen J. Fahey and Terrence M. Gosliner. 1999.Description of Three New Species of Halgerda from theWestern Indian Ocean with a Redescription of Halgerda formosa Bergh, 1880. Proceedings of the California Academy of Sciences, 51(8): 365-383, 8 Figs.

Photo courtesy of Terry Gosliner
Taxonomic text courtesy of Shireen Fahey

Photo of Dr. Terry Gosliner, Director of Research and Curator of Invertebrates at the California Academy of Sciences in Golden Gate Park, San Francisco, California and Shireen Fahey, Terrys graduate student from San Francisco State University.

Shireen is in the Marine Biology program and for her thesis, she is developing the phylogeny and biogeography of the nudibranch genus Halgerda. She has started with a set of morphological characters but intends to include molecular and biochemical character sets.

Send Shireen email at sfahey@sfsu.edu
Send Terry email at tgosliner@casnotes1.calacademy.org

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