# Halgerda

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

## 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. In 2018 another six new species were described from Mozambique, highlighting the number of undescribed species on the African coast of the Indian Ocean. A number of undescribed species are known and many species show considerable variation across their ranges, which may indicate that more cryptic species exist.

## Distribution

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.

## Species

Species within the genus Halgerda include:
* Halgerda abyssicola Fahey & Gosliner, 2000
* Halgerda albocristata Gosliner & Fahey, 1998
* Halgerda anosy Donohoo & Gosliner, 2023
* Halgerda aurantiomaculata (J. K. Allan, 1932)
* Halgerda azteca Fahey & Gosliner, 2000
* Halgerda bacalusia Fahey & Gosliner, 1999
* Halgerda batangas Carlson & Hoff, 2000
* Halgerda berberiani Donohoo & Gosliner, 2023
* Halgerda biqiea Donohoo & Gosliner, 2023
* Halgerda brunneomaculata Carlson & Hoff, 1993
* Halgerda brycei Fahey & Gosliner, 2001
* Halgerda carlsoni Rudman, 1978
* Halgerda dalanghita Fahey & Gosliner, 1999
* Halgerda diaphana Fahey & Gosliner, 1999
* Halgerda dichromis Fahey & Gosliner, 1999
* Halgerda fibra Fahey & Gosliner, 2000
* Halgerda formosa Bergh, 1880
* Halgerda graphica Basedow & Hedley, 1905
* Halgerda guahan Carlson & Hoff, 1993
* Halgerda gunnessi Fahey & Gosliner, 2001
* Halgerda hervei Donohoo & Gosliner, 2023
* Halgerda indotessellata Tibiriçá, Pola & Cervera, 2018
* Halgerda iota Yonow, 1994
* Halgerda jennyae Tibiriçá, Pola & Cervera, 2018
* Halgerda johnsonorum Carlson & Hoff, 2000
* Halgerda labyrinthus Donohoo & Gosliner, 2023
* Halgerda leopardalis Tibiriçá, Pola & Cervera, 2018
* Halgerda maaikeae Donohoo & Gosliner, 2023
* Halgerda malesso Carlson & Hoff, 1993
* Halgerda mango Donohoo & Gosliner, 2023
* Halgerda maricola Fahey & Gosliner, 2001
* Halgerda meringuecitrea Tibiriçá, Pola & Cervera, 2018
* Halgerda mesophotica Donohoo & Gosliner, 2023
* Halgerda mozambiquensis Tibiriçá, Pola & Cervera, 2018
* Halgerda nuarrensis Tibiriçá, Pola & Cervera, 2018
* Halgerda okinawa Carlson & Hoff, 2000
* Halgerda onna Fahey & Gosliner, 2001
* Halgerda orientalis G.-Y. Lin, 1991
* Halgerda orstomi Fahey & Gosliner, 2000
* Halgerda paliensis (Bertsch & S. Johnson, 1982)
* Halgerda pattiae Donohoo & Gosliner, 2023
* Halgerda paulayi Donohoo & Gosliner, 2023
* Halgerda profunda Donohoo & Gosliner, 2023
* Halgerda punctata Farran, 1902
* Halgerda radamaensis Donohoo & Gosliner, 2023
* Halgerda scripta Donohoo & Gosliner, 2023
* Halgerda stricklandi Fahey & Gosliner, 1999
* Halgerda takipsilim Donohoo & Gosliner, 2023
* Halgerda terramtuentis Bertsch & S. Johnson, 1982
* Halgerda tessellata (Bergh, 1880)
* Halgerda theobroma Fahey & Gosliner, 2001
* Halgerda toliara Fahey & Gosliner, 1999
* Halgerda wasinensis Eliot, 1904
* Halgerda willeyi Eliot, 1904
* Halgerda xishaensis G.-Y. Lin, 1975
* Halgerda batangas
* Halgerda brunneomaculata
* Halgerda carlsoni
* Halgerda formosa
* Halgerda guahan
* Halgerda indotesselata
* Halgerda malesso
* Halgerda punctata
* Halgerda stricklandi
* Halgerda terramtuentis
* Halgerda tessellata
* Halgerda wasinensis
* Halgerda willeyi