• Acetabularia acetabulum (Linnaeus) P.C. Silva, 1952: isogamous
• Acetabularia caliculus J.V.Lamouroux, 1824: isogamous
• Acetabularia chiavonica Squinabol, 1902 †: isogamous
• Acetabularia crenulata J.V. Lamouroux, 1816: isogamous
• Acetabularia crenulata J.V.Lamouroux, 1816: isogamous
• Acetabularia dentata Solms-Laubach, 1895: isogamous
• Acetabularia dentata Solms-Laubach, 1895: isogamous
• Acetabularia farlowii Solms-Laubach, 1895: isogamous
• Acetabularia farlowii Solms-Laubach, 1895: isogamous
• Acetabularia haemmerlingii H.G.Schweiger & Berger, 1975: isogamous
• Acetabularia jalakanyakae Sani, Madhu, R.K.Kohli, K.Gupta & Bast, 2021: isogamous
• Acetabularia kilneri J.Agardh, 1887: isogamous
• Acetabularia major G.Martens, 1866: isogamous
• Acetabularia moldavica Barattolo, Ionesi & Ţibuleac, 2019 †: isogamous
• Acetabularia peniculus (R.Brown ex Turner) Solms-Laubach, 1895: isogamous
• Acetabularia ryukyuensis Okamura & Yamada, 1932: isogamous
• Acetabularia schenckii K. Möbius, 1889: isogamous
• Acetabularia schenckii Möbius, 1889: isogamous
• Acrosiphonia arcta (Dillwyn) Gain, 1912: isogamous
• Acrosiphonia coalita (Ruprecht) Scagel, Garbary, Golden & M.W.Hawkes, 1986: isogamous
• Acrosiphonia congregata (Agardh) Kjellman: isogamous
• Acrosiphonia duriuscula (Ruprecht) Yendo, 1916: isogamous
• Acrosiphonia effusa Kjellman, 1893: isogamous
• Acrosiphonia flabelliformis Jónsson: isogamous
• Acrosiphonia flaccida Kjellman: isogamous
• Acrosiphonia flagellata Kjellman, 1893: isogamous
• Acrosiphonia grandis Kjelmann, 1893: isogamous
• Acrosiphonia hemisphaerica Kjellman, 1893: isogamous
• Acrosiphonia heterocladia (Sakai) K.L.Vinogradova, 1979: isogamous
• Acrosiphonia incurva Kjellman, 1893: isogamous
• Acrosiphonia minima (Fosl.) Kjellman: isogamous
• Acrosiphonia orientalis (J.Agardh) P.C.Silva, 1996: isogamous
• Acrosiphonia penicilliformis (Foslie) Kjellman, 1893: isogamous
• Acrosiphonia saxatilis (Ruprecht) K.L.Vinogradova, 1979: isogamous
• Acrosiphonia setacea Kjellman: isogamous
• Acrosiphonia sonderi (Kützing) Kornmann, 1962: isogamous
• Acrosiphonia spinescens (Kützing) Kjellman, 1893: isogamous
• Acrosiphonia stolonifera Kjellman, 1893: isogamous
• Anadyomene cladophoroides (W.J.Gilbert) Guiry & A.R.Sherwood, 2023: isogamous
• Anadyomene crispa Chevallier: isogamous
• Anadyomene eseptata Gilbert, 1961: isogamous
• Anadyomene gigantodictyon M.M.Littler & D.S.Littler, 2012: isogamous
• Anadyomene howei D.S.Littler & Littler, 1991: isogamous
• Anadyomene lacerata D.S.Littler & Littler, 1991: isogamous
• Anadyomene leclancheri Decaisne, 1844: isogamous
• Anadyomene lenormandii J.E.Gray: isogamous
• Anadyomene linkiana D.S.Littler & M.M.Littler, 1991: isogamous
• Anadyomene menziesii (J.E.Gray) J.Agardh, 1887: isogamous
• Anadyomene muelleri Sonder: isogamous
• Anadyomene pavonina (J.Agardh) Wille, 1910: isogamous
• Anadyomene plicata C.Agardh, 1823: isogamous
• Anadyomene reticulata Askenasy, 1888: isogamous
• Anadyomene rhizoidifera A.B.Joly & Pereira, 1973: isogamous
• Anadyomene saldanhae A.B.Joly & E.C.Oliveira, 1969: isogamous
• Anadyomene stellata (Wulfen) C.Agardh, 1823: isogamous
• Anadyomene wrightii Harvey ex J.E.Gray, 1866: isogamous
• Asperococcus bullosus J.V.Lamouroux, 1813: isogamous
• Asperococcus cystosirae (Ruprecht) Zanardini: isogamous
• Asperococcus ensiformis (Delle Chiaje) M.J.Wynne, 2003: isogamous
• Asperococcus fistulosus (Hudson) W.J.Hooker, 1833: isogamous
• Asperococcus fragilis (J.Agardh) Zanardini: isogamous
• Asperococcus norvegicus Kylin, 1910: isogamous
• Asperococcus scaber Kuckuck, 1899: isogamous
• Asperococcus tortilis Suhr, 1836: isogamous
• Batophora occidentalis (Harvey) S.Berger & Kaever ex M.J.Wynne, 1998: isogamous
• Batophora oerstedii J.Agardh, 1854: isogamous
• Battersia arctica (Harvey) Draisma, Prud'homme & H.Kawai, 2010: isogamous
• Battersia mirabilis Reinke ex Batters, 1890: isogamous
• Battersia norrisii (Hollenberg) Gabrielson, Lindstrom & O'Kelly, 2012: isogamous
• Battersia plumigera (Holmes ex Hauck) Draisma, Prud'homme & H.Kawai, 2010: isogamous
• Battersia racemosa (Greville) Draisma, Prud'homme & H.Kawai, 2010: isogamous
• Bolbocoleon jolyi Yamaguishi-Tomita, 1970: isogamous
• Bolbocoleon piliferum Pringsheim, 1862: isogamous
• Boodlea coacta (Dickie) G.Murray & De Toni, 1889: isogamous
• Boodlea composita (Harvey) F.Brand, 1904: isogamous
• Boodlea montagnei (Harvey ex J.E.Gray) Egerod, 1952: isogamous
• Boodlea struveoides M.Howe, 1918: isogamous
• Boodlea vanbosseae Reinbold, 1905: isogamous
• Capsosiphon aureus V.J.Chapman, 1952: isogamous
• Capsosiphon fulvescens (C.Agardh) Setchell & N.L.Gardner, 1920: isogamous
• Chaetomorpha adrianii Feldmann, 1936: isogamous
• Chaetomorpha aerea (Dillwyn) Kützing, 1849: isogamous
• Chaetomorpha akineta M.A.Sahito, Z.A.Nizamani & S.M.Leghari: isogamous
• Chaetomorpha antennina (Bory) Kützing, 1847: isogamous
• Chaetomorpha auricoma (Suhr) Blair, 1983: isogamous
• Chaetomorpha baicalensis K.I.Meyer [C.I.Meyer], 1922: isogamous
• Chaetomorpha bangioides E.Y.Dawson, 1950: isogamous
• Chaetomorpha basiretrorsa Setchell, 1926: isogamous
• Chaetomorpha billardieri Kützing, 1847: isogamous
• Chaetomorpha brachygona Harvey, 1858: isogamous
• Chaetomorpha breviarticulata Hauck, 1884: isogamous
• Chaetomorpha californica Collins, 1900: isogamous
• Chaetomorpha cannabina (Areschoug) Kjellman, 1889: isogamous
• Chaetomorpha capillaris (Kützing) Børgesen, 1925: isogamous
• Chaetomorpha cartilaginea M.Howe, 1914: isogamous
• Chaetomorpha chapmanii Molinari & Guiry, 2021: isogamous
• Chaetomorpha clavata Kützing, 1847: isogamous
• Chaetomorpha coliformis (Montagne) Kützing, 1849: isogamous
• Chaetomorpha crassa (C.Agardh) Kützing, 1845: isogamous
• Chaetomorpha curta (Skab.) Skabitschevsky, 1970: isogamous