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). 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. . Seven species of Halgerda were described in the years 1880–1905, two species in 1932–1949, four species from 1975 to 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.
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. Halgerda Bergh, 1880. Accessed through: World Register of Marine Species on 2023-06-18.
References