Quagga mussel 1648732 224274942 2008-07-08T02:57:54Z Howcheng 314721 rm unclear sentence {{Taxobox | name = Quagga Mussel | image = Dreissena bugensis.jpg | image_width = 240px | regnum = [[Animalia]] | phylum = [[Mollusc]]a | classis = [[Bivalvia]] | subclassis = [[Heterodonta]] | ordo = [[Veneroida]] | superfamilia = [[Dreissenoidae]] | familia = [[Dreissenidae]] | genus = ''[[Dreissena]]'' | species = '''''D. rostriformis''''' | subspecies = '''''D. r. bugensis''''' | binomial = ''Dreissena rostriformis'' }} [[Image:Quagga mussels GLERL 1.jpg|thumb|240px|right|Quagga mussels in [[Lake Michigan]] sediment sample]] The '''quagga mussel''' (''Dreissena rostriformis bugensis'') is one of seven ''[[Dreissena]]'' species. This species is indigenous to the [[Dnieper River]] drainage of [[Ukraine]]. The species is named after the [[quagga]], an extinct subspecies of African [[zebra]], possibly because, like the quagga, its stripes fade. It is currently of major concern in the United States as an [[invasive species]]. ==Appearance== The quagga mussel shell is striped, as is that of the [[zebra mussel]], but the quagga shell is paler toward the hinge. There is a large range of shell morphologies, including a distinct morph in [[Lake Erie]] that is pale or completely white. The quagga is slightly larger than the zebra mussel, about {{convert|20|mm|in|1}} wide, roughly about the size of an adult human's thumbnail. The quagga has a rounded [[carina (anatomy)|carina]] and a convex ventral side. ==Diet== The quagga mussel is a [[filter feeder]]. They use their [[cilia]] to pull water into their shell cavity where it passes through an incurrent siphon and it is here that desirable particulate matter is removed. Each adult mussel is capable of filtering one or more liters of water each day, where they remove [[phytoplankton]], [[zooplankton]], [[algae]], and even their own [[veliger]]s. Any undesirable particulate matter is bound with [[mucus]], known as [[pseudofeces]], and ejected out the incurrent siphon. The particle-free water is then discharged out the excurrent siphon. ==Reproduction== The quagga mussel is a prolific breeder, possibly contributing to its spread and abundance. Dreissena are [[dioecious]] (either male or female) with external fertilization. A fully mature female mussel is capable of producing up to one million eggs per season. After fertilization, pelagic microscopic larvae, or veligers, develop within a few days and these veligers soon acquire minute bivalve shells. Free-swimming veligers drift with the currents for three to four weeks feeding by their hair-like cilia while trying to locate suitable substrata to settle and secure [[byssal thread]]s. Mortality in this transitional stage from planktonic veliger to settled juveniles may exceed 99%.<ref name="usgs">{{cite web | url=http://cars.er.usgs.gov/Nonindigenous_Species/Zebra_mussel_FAQs/Dreissena_FAQs/dreissena_faqs.html | title=Dreissena FAQs | work=Florida Integrated Science Center - Gainesville | publisher=[[United States Geological Survey]] | first=Myriah | last=Richerson | date=[[January 11]] [[2007]] | accessdate=2008-03-25}}</ref> ==Invasive species== Zebra mussels, the first Dreissenid mussel introduced in North America, rapidly spread throughout many major river systems and the [[Great Lakes]] causing substantial ecological and environmental impacts. The quagga mussel was first observed in North America in September 1989 when it was discovered in [[Lake Erie]] near [[Port Colborne, Ontario]]. It was not identified as a distinct species until 1991. The introduction of both Dreissenid species into the Great Lakes appears to be the result of [[sailing ballast|ballast]] water discharge from transoceanic ships that were carrying veligers, juveniles, or adult mussels. The genus Dreissena is highly polymorphic and prolific with high potential for rapid adaptation attributing to its rapid expansion and colonization. Still, there are other factors that can aid in the spread of these species across North American waters, such as, larval drift in river systems or fishing and boating activities that allow for overland transport or movement between water basins. The success of overland transport of Dreissena species depends on their ability to tolerate periods of desiccation, and results suggest that, given temperate summer conditions, adult Dreissena may survive 3-5 days of aerial exposure.<ref name="usgs"/> Quaggas are prodigious water filterers, removing substantial amounts of phytoplankton and suspended particulate from the water. By removing the phytoplankton, quaggas in turn decrease the food source for zooplankton, therefore altering the food web. Impacts associated with the filtration of water include increases in water transparency, decreases in mean [[chlorophyll]] concentrations, and accumulation of pseudofeces. Water clarity increases light penetration causing a proliferation of aquatic plants that can change species dominance and alter the entire ecosystems. The pseudofeces that is produced from filtering the water accumulates and creates a foul environment. As the waste particles decompose, oxygen is used up, and the [[pH]] becomes very acidic and toxic byproducts are produced. In addition, quagga mussels accumulate organic pollutants within their tissues to levels more than 300,000 times greater than concentrations in the environment and these pollutants are found in their pseudofeces, which can be passed up the food chain, therefore increasing wildlife exposure to organic pollutants (Snyder et al., 1997). Another major threat involves the fouling of native freshwater mussels. [[Image:Quagga Map lg.jpg|thumb|Map showing distribution of quaggas in the U.S.]] Dreissena's ability to rapidly colonize hard surfaces causes serious economic problems. These major [[biofouling]] organisms can clog water intake structures, such as pipes and screens, therefore reducing pumping capabilities for power and [[water treatment]] plants, costing industries, companies, and communities. Recreation-based industries and activities have also been impacted; [[dock]]s, [[breakwall]]s, [[buoy]]s, [[boat]]s, and [[beach]]es have all been heavily colonized. Many of the potential impacts of Dreissena are unclear due to the limited time scale of North American colonization. Nonetheless, it is clear that the genus Dreissena is highly polymorphic and has a high potential for rapid adaptation to extreme environmental conditions, possibly leading to significant long-term impacts on North American waters. Also, the colonization of deeper water by ''D. r. bugensis'', exposes the quagga to a new range of environmental conditions and new habitats. It causes many of the same problems (damaging boats, power plants, and harbors and destroying the native mussel population) as the equally invasive zebra mussel of [[Russia]]. It is also displacing native burrowing [[amphipod]] (''Diporeia hoyi'') from the deep waters of Lake Erie. In January 2007, quagga mussels were discovered at a marina in the Nevada portion of [[Lake Mead]], and two other lakes on the [[Colorado River]], [[Lake Mohave]] and [[Lake Havasu]].<ref>[http://www.azcentral.com/news/articles/0123water-mussels0123.html The Arizona Republic, Jan. 23, 2007 - Mussels invading Arizona waterways, by Shaun McKinnon]</ref> In 2008 the threat of quagga mussels being introduced at [[Lake Casitas]] and Westlake Lake in California from recreational boating resulted in the lakes banning the use of outside boats.<ref>[http://www.venturacountystar.com/news/2008/mar/07/westlake-lake-joins-casitas-in-boat-ban-linked/ Westlake Lake joins Casitas in boat ban linked to mussel]</ref> As of March 2008, other lakes such as Castaic and Lake Cachuma are considering similar bans. <ref>[http://www.santamariatimes.com/articles/2008/03/12/news/featurednews/news01.txt Action on mussel delayed]</ref> ==Quagga mussels as food== In 1994, invasive species biologist [[Anthony Ricciardi]] determined that [[yellow perch]] did not find the invasive dreissenid species palatable. In 2004, he determined that yellow perch, over the intervening 10 years, had developed an appetite for the Quagga mussel. While sounding like good news, it is tempered with the knowledge that it introduces contaminants into the [[food chain]], notably ''[[Clostridium botulinum]]''.<ref>*[http://www.mcgill.ca/reporter/37/02/ricciardi/ Perch Discover Nature's Junk Food] - McGill ''Reporter'' article (September 23, 2004)</ref> Likewise, although they are edible by humans, it is not recommended due to the accumulation of pollutants within the mussel's body. == External links == *[http://www.redpath-staff.mcgill.ca/ricciardi/dreissena.html ''Dreissena bugensis''] - Small blurb on Quagga mussel (with pic) on Anthony Ricciardi's site. Links to various papers and blurbs on other invasive species. == References == {{Reflist}} [[Category:Dreissenidae]] [[Category:Invasive animal species]]