六放海绵纲（Hexactinellida）为多孔动物门的一个纲。该纲动物具有硅质骨针，有些骨针能聚合成网状的骨架。骨骼中无海绵质。本纲又称为玻璃海绵。六放海绵纲动物大多数生活在200～8500米的海底。常被用做觀賞用途，主要生存於深海當中，這種海綿也與海裡的甲殼類生物共生，通常會有兩隻，一公一母的蝦類以此為家。在日本，骨骼經過人類製作之後，成為一種愛情的紀念品。英語俗名Venus' Flower Basket。而受到一定程度的歡迎。

型態
形體大，骨骼全由矽質骨針組成，無海綿絲。典型的大骨針多為六射三軸針，互成直角，故又稱六射海綿綱。此外還有四射雙軸針等。骨針往往連線形成立體格架。小骨針呈六射星狀或雙盤狀。簡單複溝型，鞭毛室大；某些古生代種類還有單溝型。元古代晚期至現代。

在眾多能拿來跟玻璃相比的透明物種當中，最接近玻璃的應當屬維納斯花籃。它們長得像一個精緻的花瓶，因此而得名。它們也被稱作玻璃海綿，它們骨骼的主要成分是矽，這也是玻璃的主要成分。

主要特徵還有海綿特有的矽質骨針，並集結成纖巧的幾何網路，如偕老同穴（Venus's flower basket）一般，玻璃海綿中央腔內常寄居一對共生儷蝦，蝦在幼蟲的時候住進去，長大之後就逃不出去了。然後兩隻蝦被囚困其中，靠流進中央腔的水流而獲食物。這樣的海綿動物在日本成為了頗受歡迎的結婚禮物。

食性
玻璃海綿以從水中過濾而來的最小浮游生物為食，最大可以生長到兩米以上，它們花瓶般的身體構造為魚類、無脊椎動物以及其它海洋生物提供了完美的躲藏、產卵和生存的環境。玻璃海綿像珊瑚一樣開闢著自己的棲息地，在一定程度上，它們就像海床上的城市，無論它們生長在何處，總是會吸引來其它的海洋生物。

分类 
六放海绵纲分为两个亞綱：
 双盘海绵亞綱 Amphidiscophora
 六放海绵亞綱 Hexasterophora
本纲包含以下目：
 双盘海绵目 Amphidiscosida
 灯笼海绵目 Lychniscosida
 松骨海绵目 Lyssacinosida
 权杖海绵目 Sceptrulophora
目地位未定的科：
 Aglithodictyidae
 Asthenospongiidae
 Celyphiidae
 Cliefdenellidae
 Colospongiidae
 Cystispongiidae
 Cystothalamiidae
 Dictyospongiidae
 Dierespongiidae
 Docodermatidae
 Hemidiscellidae
 Hintzespongiidae
 Hyalostellidae
 Hydnodictyidae
 Leptophragmatidae
 Multivasculatidae
 Pachyteichismatidae
 Pattersoniidae
 Pileolitidae
 Pileospongiidae
 Pillaraspongiidae
 Plieolitidae
 Porispongiidae
 Protospongiidae
 Sebargasiidae
 Staurodermatidae
 Stereodictyidae
 Stromatidiidae
 Teganiidae
 Thaumastocoeliidae
 Titusvillidae
 Titusvilliidae
 Triactinellidae
 Uphantenidae
 Wareembaiidae
目和科地位未定的属：
 Acanthactinella Hinde, 1887
 Aglithodictya Hall & Clarke, 1898
 Antrispongia Quenstedt, 1878
 Arystidictyon
 Asociatella Hurcewicz, 1985
 Astroconia Sollas, 1881
 Aulacosia Rauff, 1933
 Aulodomus Schrammen, 1936
 Australispongia Xiping & Knoll, 1996
 Azyrtalia Nazarov, 1973
 Baccispongia Quenstedt, 1877
 Belonisia Rauff, 1933
 Bothroconis King, 1850
 Botryodictya Hall & Clarke, 1898
 Caesaria Quenstedt, 1858
 Calpidospongia Wu, 1989
 Carbonella Hurcewicz & Czarniecki, 1986
 Carinthiaspongus Krainer & Mostler, 1992
 Caseispongia Quenstedt, 1878
 Chelispongia Webby & Trotter, 1993
 Chirospongia Miller, 1889
 Cincliderma Hinde, 1883
 Clepsydrospongia Hall & Clarke, 1898
 Corticospongia Caster, 1939
 Crepospongia Wu, 1989
 Crucispongia Quenstedt, 1877
 Cryptodictya Hall, 1890
 Cyathophycella Rigby & Stuart, 1988
 Cyrtobolia Pocta, 1883
 Czarnockiella Hurcewicz & Czarniecki, 1986
 Decumbispongia Botting, Muir, Li & Lin, 2013
 Dialyscyphia Hurcewicz & Czarniecki, 1986
 Diaretula Schmidt, 1879
 Dilatispongia Botting, 2004
 Diphyllospira Herrmann-Degen, 1980
 Diplopleura Regnard, 1925
 Dvorcia Nekvasilová & Štemproková, 1960
 Emploca Sollas, 1883
 Eubrochus Sollas, 1876
 Euplectinella Termier, Termier & Thibieroz, 1990
 Eutactostomium Herrmann-Degen, 1980
 Farreopsis Schrammen, 1924
 Flosculus Xiping & Knoll, 1996
 Gonamispongia Korshunov, 1968
 Gongylospongia Hall & Clarke, 1898
 Griphodictya Hall & Clarke, 1898
 Haljalaspongia Botting & Rhebergen, 2011
 Hallodictya Hall & Clarke, 1898
 Helicodictya Hall & Clarke, 1898
 Hemidiagoniella Botting, 2004
 Hemidiscella
 Hexactractiella
 Hexatractiella Mehl, 1996
 Hillendia Reid, 1964
 Hintzesnonaia
 Hodsia Moisseev, 1939
 Holasterella
 Holasterella Carter, 1879
 Hunteria Van Soest & Hooper, 2020
 Hyalocaulus Marshall & Meyer, 1877
 Hydnocerina Clarke, 1920
 Idiodictyon de Laubenfels, 1955
 Iowaspongia Thomas, 1923
 Irpaspongia Mehl & Mostler, 1994
 Ithacadictya Caster, 1939
 Kaiyangites Qian & Yin, 1984
 Koleostoma Regnard, 1925
 Kometia Webby & Trotter, 1993
 Konyrium Nazarov & Popov, 1976
 Krainerella Krainer & Mostler, 1992
 Laocaetis
 Larispongia Carrera, 1998
 Lecanocoelospongia Wu, 1989
 Lithospongia Duchassaing & Michelotti, 1864
 Lobospongia Hurcewicz, 1985
 Lonsda de Laubenfels, 1955
 Lopanella Pocta, 1883
 Lysactinella
 Mastodictya Hall & Clarke, 1898
 Mastodictyum Sollas, 1883
 Megastylia
 Mimeticosia
 Multiloqua de Laubenfels, 1955
 Multivasculatus Howell & Van Houten, 1940
 Mysterium de Laubenfels, 1955
 Nephelispongia
 Nitidus de Laubenfels, 1955
 Octobrum de Laubenfels, 1955
 Oospongia Wu, 1989
 Oxyrhizium Schrammen, 1912
 Ozospongia
 Pachaulidium Schmidt, 1880
 Pachylepisma Schrammen, 1902
 Palaeophragmodictya Gehling & Rigby, 1996
 Palaeorossella Li et al., 2019
 Palaeostauronema
 Paleophragmodictya Gehling & Rigby, 1996
 Paleostauronema Hurcewicz, 1985
 Paracraticularia Schrammen, 1936
 Parahexactinella Reid, 1963
 Petalope Pocta, 1883
 Phormosella Hinde, 1888
 Pinnatispongia Xiping & Knoll, 1996
 Placochlaenia Pomel, 1872
 Placospongia Wu, 1989
 Plecteurete Herrmann-Degen, 1980
 Plecteurette
 Plectoderma Hinde, 1883
 Plectospyris Sollas, 1883
 Pleodioria Öpik, 1961
 Polonoscyphia Hurcewicz, 1985
 Polyosepia
 Polyplectella Ruedemann, 1925
 Polyptycha Defretin-Lefranc, 1961
 Polyschema Oppliger, 1915
 Polystigmatium Schrammen, 1912
 Polysyge
 Poriferella Hurcewicz, 1985
 Porospongia d'Orbigny, 1849
 Prenehydnoceras Hurcewicz & Czarniecki, 1986
 Proeurete Schrammen, 1902
 Protoarmstrongia Caster, 1941
 Protremadictyon Hurcewicz, 1985
 Psephosyllogus Schrammen, 1936
 Pseudotragos Nutsubidze, 1965
 Pyrenospongia Wu, 1989
 Ramulospongia Hurcewicz, 1985
 Repospongia Hurcewicz & Czarniecki, 1986
 Retifungus Rietschel, 1970
 Rhabdosispongia Hall & Clarke, 1898
 Rhabdostauridium Schmidt, 1880
 Rhakistella Weller, 1931
 Rhogostomium Schrammen, 1936
 Rhombedonium Schrammen, 1936
 Rhombodictyon Whitfield, 1886
 Rhopalicna
 Rigbykia Özdikmen, 2009
 Roemerispongia Hall & Clarke, 1898
 Rosella Vassiljeva, 1988
 Rugosoderma Howell, 1957
 Scotospongia Krainer & Mostler, 1992
 Sestrocladiella Howell, 1957
 Silicunculus Bengtson, 1986
 Solusrectus Botting, 2004
 Spiractinella Hinde, 1887
 Sulugurella Pelman, Ermak, Fedorov, Luchinina, Zhuravleva, Repina, Bondarev & Borodaevskaya, 1990
 Sycodictya Ruedemann, 1925
 Synaulia Pocta, 1883
 Teganiella Rigby, 1985
 Teganium Rauff, 1894
 Testiispongia Rigby, 1983
 Textispongia Quenstedt, 1877
 Thamnodictya Hall, 1884
 Uphantena
 Uralonema
 Ursaspongia Rigby, 1985
 Ventriculita
 Walcottella de Laubenfels, 1955
 Xenoschrammenus
 Xylospongia Hérenger, 1942
 Zittelospongia Malfatti, 1901

参考文献 

 
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