Halgerda dichromis
Fahey & Gosliner, 1999

Suborder: DORIDINA
Family: Dorididae


South Africa, (east coast)


Upper: South Coast KwaZulu-Natal, South Africa. Near Port Shepstone. Rocky reef - 20m., October 1999. Size: 50 mm. Lower: Park Rynie, KwaZulu-Natal, 30 m, South Africa, 24 March 2009. Length: 30 mm. mating pair showing colour variation. Photos: Valda Fraser.

Described from a single specimen from South Africa it was previously figured in Gosliner, 1987 p.69 [no.89] as H. formosa. Fahey & Gosliner compare it with H. formosa and note that it differs externally in having indistinct ridges and both black and yellow-orange lines, as well as anatomical differences. It should also be compared with H. toliara. It also has similarities to H. willeyi but in that species the yellow lined ridges are much more numerous and there many fine black lines. More specimens are needed to see just what colour variation is found in this species.

Note added March 2009: Fahey & Gosliner (2003) confirm the photos above are all colour variants of H. dichromis.

Compare with:
H. willeyi - yellow reticulate pattern, many black lines - no black spots around mantle edge.
H. formosa (Bergh, 1880) - yellow reticulate pattern - some black spotting around mantle skirt, and small whitish pustules near edge.
H. toliara Fahey & Gosliner, 1999. - yellow reticulate pattern - no black spots on mantle, small yellow pustules near edge.

  • Fahey, S. & Gosliner, T.M. (1999) description of three new species of Halgerda from the western Indian Ocean, with a redescription of Halgerda formosa, Bergh, 1880. Proceedings of the California Academy of Sciences, 51(8): 365-383.
  • Fahey, S. J. & Gosliner, T. M. (2003) Redescription of Halgerda graphica Basedow and Hedley,1905, with observations on external morpohological variation within selected species of Halgerda (Mollusca: Nudibranchia). Proceedings of the California Academy of Sciences, 54, 393-406.
  • Gosliner, T. (1987) Nudibranchs of Southern Africa. Sea Challengers: Monterey
  • Rudman, W.B. (1978) The dorid opisthobranch genera Halgerda and Sclerodoris from the Indo-West Pacific. Zoological Journal of the Linnean Society 62: 59-88.
Authorship details
Rudman, W.B., 1999 (November 18) Halgerda dichromis Fahey & Gosliner, 1999. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/halgdich

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