Sycon

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, 194 1
 * 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, 1929