Halgerda
{{Short description|Genus of gastropods}}
{{for|the Icelandic saga character|Hallgerda}}
{{Automatic_taxobox
|image=Halgerda stricklandi.jpg
|image_caption=Halgerda stricklandi
|taxon=Halgerda
|authority=Bergh, 1880Bergh, L.S.R. 1880. Beiträge zur Kenntniss der japanischen Nudibranchien. I. Verhandlungen der königlich-kaiserlich Zoologisch-botanischen Gesellschaft in Wien (Abhandlungen) 30:155-200, pls. 1-5, pages 191-5.
|type_species=Halgerda formosa
|type_species_authority=Bergh, 1880
}}
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).Odhner N. H. (1934). "The Nudibranchiata, British Antarctic ("Terra Nova") Expedition, 1910". Natural History Report, Zoology 7(5): 229-310.
Halgerdidae Odhner, 1926, is treated as a synonym of Discodorididae in the taxonomy of Bouchet & Rocroi (2005).{{Bouchet 2005}} See also Valdés (2002).Valdés A. (2002). "A phylogenetic analysis and systematic revision of the cryptobranch dorids (Mollusca, Nudibranchia, Anthobranchia)". Zoological Journal of the Linnean Society 136: 535-636. {{doi|10.1046/j.1096-3642.2002.00039.x}}.
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.Tibiriçá, Y.; Pola, M.; Cervera, J. L. (2018). Systematics of the genus Halgerda Bergh, 1880 (Heterobranchia : Nudibranchia) of Mozambique with descriptions of six new species. Invertebrate Systematics. A number of undescribed species are known and many species show considerable variation across their ranges, which may indicate that more cryptic species exist.Gosliner, T.M., Behrens,D.W. & Valdes,A., 2008. Indo-Pacific Nudibranchs and Sea Slugs. A field guide to the World's most diverse fauna. Sea Challengers Natural History Books & The California Academy of Sciences. {{ISBN|978-0-9700574-3-3}}
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:MolluscaBase eds. (2023). MolluscaBase. [https://www.marinespecies.org/aphia.php?p=taxdetails&id=205320 Halgerda Bergh, 1880]. Accessed through: World Register of Marine Species on 2023-06-18.
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{{linked specieslist
| 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
}}
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Image:Halgerda batangas.jpg|Halgerda batangas
Image:Halgerda brunneomaculata.jpg|Halgerda brunneomaculata
Image:Halgerda carlsoni.jpg|Halgerda carlsoni
Image:Halgerda formosa.jpg|Halgerda formosa
Image:Halgerda guahan 2.jpg|Halgerda guahan
Image:Halgerda indotesselata B12 4392a.jpg|Halgerda indotesselata
Image:Halgerda malesso 2.jpg|Halgerda malesso
Image:Halgerda-punctata.jpg|Halgerda punctata
Image:Halgerda stricklandi 003.jpg|Halgerda stricklandi
Image:Halgerda terramtuentis.jpg|Halgerda terramtuentis
Image:Nudibranch - Halgerda tessellata.jpg|Halgerda tessellata
Image:Halgerda wasinensis.jpg|Halgerda wasinensis
Image:Halgerda willeyi 2.jpg|Halgerda willeyi