{{Short description|Family of gastropods}} {{Automatic_taxobox | name = Fionidae | image = Fiona pinnata.jpg | image_caption = | taxon = Fionidae | authority = Gray, 1857 | subdivision_ranks = Genera | subdivision = ''See text'' | synonyms = }}
'''Fionidae''' is a family of sea slugs, aeolid nudibranchs, marine gastropod molluscs in the superfamily Fionoidea.<ref name=WoRMS>MolluscaBase eds. (2026). MolluscaBase. Fionidae J. E. Gray, 1857. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=23039 on 2026-03-30</ref>
==Taxonomic history== This family was expanded to include Tergipedidae, Eubranchidae and Calmidae as a result of a molecular phylogenetics study.<ref>Cella, K; Carmona Barnosi, L.; Ekimova, I; Chichvarkhin, A; Schepetov, D; Gosliner, T. M. (2016). [https://dx.doi.org/10.1371/journal.pone.0167800 ''A radical solution: The phylogeny of the nudibranch family Fionidae.''] PLoS ONE. 11(12): e0167800.</ref> This was reversed in 2017 with further DNA evidence and a re-interpretation of genus and family characteristics.<ref>Korshunova, T.; Martynov, A.; Picton, B. (2017). [https://doi.org/10.11646/zootaxa.4324.1.1 Ontogeny as an important part of integrative taxonomy in tergipedid aeolidaceans (Gastropoda: Nudibranchia) with a description of a new genus and species from the Barents Sea.] Zootaxa. 4324(1): 1.</ref>
==Genera == According to Korshunova et al. (2025), genera within the family Fionidae include<ref name="Korshunova">Korshunova T.; Fletcher K.; Martynov A. (2025). [https://doi.org/10.1093/zoolinnean/zlaf057 ''The endless forms are the most differentiated—how taxonomic pseudo-optimization masked natural diversity and evolution: the nudibranch case''] Zoological Journal of the Linnean Society, Volume 204, Issue 4, August 2025, zlaf057, </ref>: * ''Fiona'' <small>Alder & Hancock [in Forbes & Hanley], 1853</small> * ''Tergiposacca'' <small>Cella, Carmona, Ekimova, Chichvarkhin, Schepetov & Gosliner, 2016</small>
Other genera not mentioned in Korshunova et al. (2025) include<ref name=WoRMS/>: * ''Zatteria'' <small>Eliot, 1902</small>
==References== {{reflist}}
== External links == * {{Commons category-inline|Fionidae}}
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Category:Fionidae Category:Taxa named by John Edward Gray