Sycon is a genus of calcareous sponges belonging to the family Sycettidae. These sponges are small, growing up to 7.5 cm with a length from 2.5 to 7.5 cm, and are tube-shaped and often white to cream in colour. They are known to aquarium hobbyists as "Pineapple" or "Q-Tip" sponges, and are frequent "hitchhikers" accidentally brought in. 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