Species
The following species are recognised in the genus ''Sycon'': *'' Sycon abyssale'' Borojevic & raat-Kleeton, 1965 *'' Sycon acanthoxea'' (Little, 1963) *'' Sycon album'' Tanita, 1942 *'' Sycon ampulla'' (Haeckel, 1870) *'' Sycon antarcticum'' (Jenkin, 1908) *'' Sycon arcticum'' (Haeckel, 1870) *'' Sycon australe'' (Jenkin, 1908) *'' Sycon avus'' Chagas & Cavalcanti, 2017 *'' Sycon barbadense'' (Schuffner, 1877) *'' Sycon bellum'' Chagas & Cavalcanti, 2017 *'' Sycon boreale'' (Schuffner, 1877) *'' Sycon brasiliense'' Borojevic, 1971 *'' Sycon calcaravis'' Hozawa, 1929 *'' Sycon caminatum'' Thacker, 1908 *'' Sycon capricorn'' Wörheide & Hooper, 2003 *'' Sycon carteri'' Dendy, 1893 *'' Sycon ciliatum'' (Fabricius, 1780) *'' Sycon coactum'' (Urban, 1906) *'' Sycon compactum'' Lambe, 1893 *'' Sycon conulosum'' Cóndor-Luján, Louzada, Hajdu & Klautau, 2018 *'' Sycon cylindricum'' Tanita, 1942 *'' Sycon defendens'' Borojevic, 1967 *'' Sycon digitiforme'' Hozawa, 1929 *'' Sycon dunstervillia'' (Haeckel, 1872) *'' Sycon eglintonense'' Lambe, 1900 *'' Sycon elegans'' (Bowerbank, 1845) *'' Sycon ensiferum'' Dendy, 1893 *'' Sycon escanabense'' Duplessis & Reiswig, 2000 *'' Sycon faulkneri'' Ilan, Gugel, Galil & Janussen, 2003 *'' Sycon formosum'' (Haeckel, 1870) *'' Sycon frustulosum'' Borojevic & Peixinho, 1976 *'' Sycon gelatinosum'' (Blainville, 1834) *'' Sycon giganteum'' Dendy, 1893 *'' Sycon globulatum'' Hozawa, 1929 *'' Sycon grantioides'' Dendy, 1916 *'' Sycon helleri'' (Lendenfeld, 1891) *'' Sycon hozawai'' Breitfuss, 1932 *'' Sycon huinayense'' Azevedo, Hajdu, Willenz & Klautau, 2009 *'' Sycon humboldti'' Risso, 1826 type species *'' Sycon inconspicuum'' (Lendenfeld, 1885) *'' Sycon incrustans'' Breitfuss, 1898 *'' Sycon karajakense'' Breitfuss, 1897 *'' Sycon kerguelense'' Urban, 1908 *'' Sycon lambei'' Dendy & Row, 1913 *'' Sycon lendenfeldi'' Row & Hozawa, 1932 *'' Sycon lingua'' (Haeckel, 1870) *'' Sycon lunulatum'' (Haeckel, 1872) *'' Sycon luteolum'' Tanita, 1942 *'' Sycon magnapicale'' Cóndor-Luján, Louzada, Hajdu & Klautau, 2018 *'' Sycon matsushimense'' Tanita, 1940 *'' Sycon mexico'' Hozawa, 1940 *'' Sycon minutum'' Dendy, 1893 *'' Sycon misakiense'' Hozawa, 1929 *'' Sycon mundulum'' Lambe, 1900 *'' Sycon munitum'' Jenkin, 1908 *'' Sycon natalense'' Borojevic, 1967 *'' Sycon okadai'' Hozawa, 1929 *'' Sycon ornatum'' Kirk, 1898 *'' Sycon oscari'' Van Soest & De Voogd, 2018 *'' Sycon parvulum'' (Preiwisch, 1904) *'' Sycon pedicellatum'' Kirk, 1911 *'' Sycon pentactinalis'' Rossi, Farina, Borojevic & Klautau, 2006 *'' Sycon plumosum'' Tanita, 1943 *'' Sycon proboscideum'' Breitfuss, 1898 *'' Sycon proboscideum'' (Haeckel, 1870) *'' Sycon protectum'' Lambe, 1896 *'' Sycon pulchrum'' Tanita, 1943 *'' Sycon quadrangulatum'' (Schmidt, 1868) *'' Sycon ramsayi'' (Lendenfeld, 1885) *'' Sycon raphanus'' Schmidt, 1862 *'' Sycon rotundum'' Tanita, 1941 *'' Sycon satsumense'' Hozawa, 1929 *'' Sycon scaldiense'' (Van Koolwijk, 1982) *'' Sycon schmidti'' (Haeckel, 1872) *'' Sycon schuffneri'' Dendy & Row, 1913 *'' Sycon setosum'' Schmidt, 1862 *'' Sycon simushirense'' Hozawa, 1918 *'' Sycon stauriferum'' (Preiwisch, 1904) *'' Sycon subhispidum'' (Carter, 1886) *'' Sycon sycandra'' (Lendenfeld, 1895) *'' Sycon tuba'' Lendenfeld, 1891 *'' Sycon urugamii'' Tanita, 1940 *'' Sycon verum'' Row & Hozawa, 1931 *'' Sycon vigilans'' Sarà & Gaino, 1971 *'' Sycon villosum'' (Haeckel, 1870) *'' Sycon yatsui'' Hozawa, 1929References
Leucosolenida Sponge genera {{calcarea-stub