Editing Lake Baikal (section)

====Sponges====

At least 18 species of [[sponge]]s occur in the lake,<ref name=Kaluzhnaya2005>Kaluzhnaya; Belikov; Schröder; Rothenberger; Zapf; Kaandorp; Borejko; Müller; and Müller (2005). ''Dynamics of skeleton formation in the Lake Baikal sponge Lubomirskia baicalensis. Part I. Biological and biochemical studies.'' Naturwissenschaften 92: 128–133.</ref> including about 15 species from the endemic family [[Lubomirskiidae]] (the remaining are from the nonendemic family [[Spongillidae]]),<ref name=Paradina2003>Paradina; Kulikova; Suturin; and Saibatalova (2003). ''The Distribution of Chemical Elements in Sponges of the Family Lubomirskiidae in Lake Baikal.'' International Symposium – Speciation in Ancient Lakes, SIAL III – Irkutsk 2002. Berliner Paläobiologische Abhandlungen 4: 151–157.</ref><ref>{{cite WoRMS |author=de Voogd, N.J.; Alvarez, B.; Boury-Esnault, N.; Carballo, J.L.; Cárdenas, P.; Díaz, M.-C.; Dohrmann, M.; Downey, R.; Hajdu, E.; Hooper, J.N.A.; Kelly, M.; Klautau, M.; Manconi, R.; Morrow, C.C. Pisera, A.B.; Ríos, P.; Rützler, K.; Schönberg, C.; Vacelet, J.; van Soest, R.W.M. |year=2021 |title=Lubomirskiidae Weltner, 1895 |id=167011 |access-date=24 November 2021}}</ref> which colonized the lake about 3.4 million years ago. The lake's sponges makes up around 44% of the [[benthic]] animal biomass.<ref>{{Cite journal|url=https://academic.oup.com/mbe/article/36/11/2462/5522662?login=false|title=Symbiosis, Selection, and Novelty: Freshwater Adaptation in the Unique Sponges of Lake Baikal|first1=Kenny, Nathan|last1=J|first2=Plese|last2=Bruna|first3=Riesgo|last3=Ana|first4=Itskovich, Valeria|last4=B|date=1 November 2019|journal=Molecular Biology and Evolution|volume=36|issue=11|doi=10.1093/molbev/m|doi-broken-date=20 February 2025 }}</ref> ''[[Lubomirskia baicalensis]]'', ''[[Lubomirskiidae|Baikalospongia bacillifera]]'', and ''[[Lubomirskiidae|B. intermedia]]'' are unusually large for freshwater sponges and can reach {{convert|1|m|ft|abbr=on}} or more.<ref name=Kaluzhnaya2005/><ref>Belikov; Kaluzhnaya; Schröder; Müller; and Müller (2007). Lake Baikal endemic sponge Lubomirskia baikalensis: structure and organization of the gene family of silicatein and its role in morphogenesis. Porifera Research: Biodiversity, Innovation and Sustainability, pp. 179–188.</ref> These three are also the most common sponges in the lake.<ref name=Kaluzhnaya2005/> While the ''Baikalospongia'' species typically have encrusting or carpet-like structures, ''L. baikalensis'' often has branching structures and in areas where common may form underwater "forests".<ref name=Kozhov1963>{{cite book| author=Kozhov, M. | year=1963 | title=Lake Baikal and Its Life | series=Monographiae Biologicae | volume=11 | pages=63–67 | isbn=978-94-015-7388-7}}</ref> Most sponges in the lake are typically green when alive because of [[symbiotic]] [[chlorophyte]]s ([[zoochlorella]]), but can also be brownish or yellowish.<ref>Müller; and Grachev, eds. (2009). ''Biosilica in Evolution, Morphogenesis, and Nanobiotechnology: Case Study Lake Baikal'', pp. 81–110. [[Springer Publishing]]. {{ISBN|978-3-540-88551-1}}.</ref>