Haplosyllis is a genus of annelids belonging to the family Syllidae.

The genus has cosmopolitan distribution.

Species:

• Haplosyllis aciculata Lattig, Martin & Aguado, 2010
• Haplosyllis agelas Uebelacker, 1982
• Haplosyllis amphimedonicola Paresque & Nogueira, 2014
• Haplosyllis anthogorgicola Utinomi, 1956
• Haplosyllis aplysinicola Lattig & Martin, 2011
• Haplosyllis aurantiaca Eisig, 1881
• Haplosyllis basticola Sardá, Avila & Paul, 2002
• Haplosyllis brevicirra Rioja, 1941
• Haplosyllis carmenbritoae Lattig, San Martín & Martin, 2007
• Haplosyllis cephalata Verrill, 1900
• Haplosyllis chaetafusorata Lattig & Martin, 2011
• Haplosyllis chamaeleon Laubier, 1960
• Haplosyllis crassicirrata Aguado, San Martín & Nishi, 2006
• Haplosyllis cratericola (Buzhinskaja, 1990)
• Haplosyllis djiboutiensis (Gravier, 1900)
• Haplosyllis eldagainoae Lattig & Martin, 2011
• Haplosyllis giuseppemagninoi Lattig & Martin, 2011
• Haplosyllis granulosa (Lattig, San Martín & Martin, 2007)
• Haplosyllis gula Treadwell, 1924
• Haplosyllis imajimai Lattig, Martin & San Martín, 2010
• Haplosyllis ingensicola Lattig, Martin & Aguado, 2010
• Haplosyllis lattigae Paresque, Fukuda & Nogueira, 2016
• Haplosyllis leylae Cepeda, Martin, Britayev, Al-Aidaroos & Lattig, 2017
• Haplosyllis loboi Paola, San Martín & Martin, 2006
• Haplosyllis navasi Lattig & Martin, 2011
• Haplosyllis nicoleae Lattig, Martin & Aguado, 2010
• Haplosyllis niphatesicola Lattig & Martin, 2011
• Haplosyllis ohma (Imajima & Hartman, 1964)
• Haplosyllis orientalis (Buzhinskaja, 1990)
• Haplosyllis rosenalessoae Paresque & Nogueira, 2014
• Haplosyllis sanchoi Lattig, Martin & San Martín, 2010
• Haplosyllis sandii Lattig, Martin & San Martín, 2010
• Haplosyllis spongicola (Grube, 1855)
• Haplosyllis spongiphila (Verrill, 1885)
• Haplosyllis streptocephala (Grube, 1857)
• Haplosyllis tenhovei Lattig, Martin & Aguado, 2010
• Haplosyllis trifalcata (Day, 1960)
• Haplosyllis uncinigera (Grube, 1878)
• Haplosyllis villogorgicola Martin, Núñez, Riera & Gil, 2000

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