Halgerda okinawa

Halgerda is a genus of sea slugs, dorid nudibranchs, shell-less marine gastropod mollusks in the family Discodorididae.

Description

The body color is translucent white with network of yellow lines and yellow-edged ridges.The mantle border is yellow. There are broken black rings and spots between the ridges. The rhinophores are yellow and translucent white with large black spots on its base. The gills have small black spots.

Distribution

All species of Halgerda are confined to the Indo-West Pacific Tropical region apart from two species which are found in warm temperate waters of South Africa and Southern Australia and one species from warm temperate Japanese waters.

Taxonomy

The genus Halgerda was classified within the family Halgerdidae by Odhner (1934). Halgerdidae Odhner, 1926, is treated as a synonym of Discodorididae in the taxonomy of Bouchet & Rocroi (2005). See also Valdés (2002). Seven species of Halgerda were described in the years 1880-1905, two species in 1932-1949, four species from 1975-1982, then 22 species in the years 1993-2001. A number of undescribed species are known and many species show considerable variation across their ranges, which may indicate that more cryptic species exist.