threads secreted by the byssal gland. There is an extremely high mortality at this stage (99%) if they do not attach to sturdy substrates. The lifespan is 3-9 years and their growth rates are .5mm a day and 1.5-2 cm a year. Diet Dreissena are filter feeders. They have both inhalant and exhalant siphons that are able to filter one Liter of water per day. They feed primarily on algae. They are able to eat microzooplankton but nothing larger. Invasion They are one of the top invasive marine species. They have high biofouling capabilities where they can colonize water supply pipes of hydroelectric and nuclear power plants, public water plants, and industrial facilities. This can cause serious problems as they constrict water flow in the pipes. They can also colonize on the hull of boats which cause drag. Also, when they arrive in a new area they are able to outcompete the native organisms for food. This causes a change in the ecosystem of this new area. The invasion of North America was facilitated by the ability to disperse in all stages of the life cycle: passive drift of pelagic larval, yearlings detach and drift, adults attach to boat hulls and other floating objects. Species Possible list of species within the genus Dreissena: Dreissena blanci Dreissena bugensis, the quagga mussel (sometimes considered a subspecies of D. rostriformis) Dreissena caspia Dreissena caspia caspia Dreissena caspia pallasi Dreissena elata elata Dreissena obtusecarinata Dreissena polymorpha, the zebra mussel Dreissena polymorpha polymorpha Dreissena polymorpha andrusovi Dreissena presbensis Dreissena rostiformis Dreissena rostriformis compressa Dreissena rostriformis distincta Dreissena rostriformis grimmi Dreissena rostriformis pontocaspica Dreissena stankovici References Benson, A.J., Raikow, D., Larson, J., Fusaro, A., Bogdanoff, A.K., and Elgin, A., 2022, Dreissena polymorpha (Pallas, 1771): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=5, Revision Date: 5/17/2021, Access Date: 4/7/2022 Kijashko, P. "Check-list for Caspian Sea molluscs". Caspian Sea Biodiversity Project under umbrella of Caspian Sea Environment Program. Kantor, Y.I.; M.V. Vinarski; A.A. Schileyko; A.V. Sysoev (2010). "Catalogue of the Continental Mollusks of Russia and Adjacent Territories" (PDF). Ruthenica, Russian Malacological Journal (Online Version). ISSN 2307-7336. Retrieved 2014-06-24. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 12 September 2014. "Taxon Details: Dreissena Van Beneden 1835". Fauna Europaea. Retrieved 12 September 2014. Rasa Bukontaite, Klaipedos Universiteto, jaun. mokslo darbuotoja, Baltijos pajurio aplinkos, tyrimu ir planavimo, LT-92294 Klaipeda, Lithuania Anastasija Zaiko, Klaipeda University, Coastal