Halgerda formosa Bergh, 1880

Yonow, Nathalie, 2012, Opisthobranchs from the western Indian Ocean, with descriptions of two new species and ten new records (Mollusca, Gastropoda), ZooKeys 197, pp. 1-130 : 23

Halgerda formosa Bergh, 1880 Plate 29

Halgerda formosa . - Yonow & Hayward 1991: 18, fig. 9 (Mauritius); Fahey and Gosliner 1999: 366, figs. 1A-B, 2, 3A (Tanzania); Debelius and Kuiter 2007: 235 (La Réunion).

Halgerda punctata . - Rudman 1978: 67, figs. 3A, 7, 8 (Zanzibar) (non Halgerda punctata Farran).

Halgerda punctata . - Gosliner 1987: 69, fig. 90 (South Africa) (non Halgerda punctata Farran).

non Halgerda formosa . - Gosliner 1987: 69, fig. 89 (South Africa) (= Halgerda dichromis Fahey & Gosliner).

Material.

Zanzibar: 10 × 5 mm pres., leg. MD Richmond (California Academy of Sciences, CASIZ 169953). - Kenya: photographs of two individuals, Malindi National Park & Watamu National Park, 5-8 m depth, MD Richmond. - La Réunion, Mauritius, and Mayotte: photographs of numerous individuals http://seaslugs.free.fr/nudibranche/a_intro.htm.

Description.

Body colour translucent white, yellow to orange-yellow ridges, and several dark spots anteriorly and posteriorly near mantle edge. Foot translucent white with at least one black spot near tip and broad pale yellow margin. Rhinophores long, translucent white with one dark brown spot on stalk; yellow on proximal third, dark brown on distal two-thirds of lamellate portion, white on elongated tip. Six gills white with black band across inner side of each rachis from base to tips of pinnules.

Distribution.

This small species was first recognised by Yonow and Hayward (1991), based upon specimens collected from Mauritius and La Réunion, the type locality. Three specimens from Western Australia ( Fahey and Gosliner 2001) extend the range of this species to the eastern Indian Ocean.