Lubomirskiidae is a family of freshwater sponges from Lake Baikal in Russia. Lubomirskia baicalensis, Baikalospongia bacillifera and B. intermedia are unusually large for freshwater sponges and can reach 1 m (3.3 ft) or more. These three are also the most common sponges in Lake Baikal. Most sponges in the lake are typically green when alive because of symbiotic dinoflagellates (zoochlorella), but can also be brownish or yellowish.