Quadrula fragosa, the winged mapleleaf mussel, once widely occurred in the Mississippi, Ohio, Tennessee, and Cumberland River drainages, as well as parts of the Ouachita River in Arkansas. There are also some reports that Quadrula fragosa once existed in parts of Oklahoma, but there is insufficient data confirming this. Currently, the only known populations of the winged mapleleaf exist in specific segments in the St. Croix river between Wisconsin and Minnesota, and in the Saline River in Arkansas. ("Population and Habitat Viability Assessment for the Winged Mapleleaf Mussel", 1998; "Quadrula fragosa", 2013; "Winged Mapleleaf Mussel (Quadrula fragosa) Recovery Plan", 1997; Hornbach, et al., 1996; Steingraeber, et al., 2007)
Winged mapleleafs live in riffles, or shallow areas, of freshwater rivers that have substrates composed of gravel, sand, mud or rubble. The rivers that they live in are characterized by having clean water that is of very high quality and has consistent stream flow. ("Population and Habitat Viability Assessment for the Winged Mapleleaf Mussel", 1998; "Quadrula fragosa-Winged Mapleleaf", 2012; "Winged Mapleleaf Mussel (Quadrula fragosa) Recovery Plan", 1997)
The shell of the winged mapleleaf has a shape that is round or pentagonal, partially inflated, and can grow up to 4 inches long. The color of their shell is a dark brown and green mix but there are also areas of a sandy tan color. Their shell, like other mussel species, has several rows of bumps, or tubercles, which run from the top of the shell, the umbo, to the edge of the shell. Along with these bumps, there are also radiating ridges that run from the umbo to the edge of the shell. Quadrula fragosa is quite similar to Quadrula quadrula, but the pattern of the rows of tubercles on Q. fragosa help differentiate it from the Q. quadrula species. ("Quadrula fragosa-Winged Mapleleaf", 2012; "U.S Fish and Wildlife Service", 2013; "Winged Mapleleaf Mussel (Quadrula fragosa) Recovery Plan", 1997; Hornbach, et al., 1996)
The fertilized eggs of the winged mapleleaf are stored in the female’s gills until they develop into small larvae called glochidia. The glochidia are released into the river current and have to attach to the fins or gills of a specific host fish to finish their development. Once the glochidia are attached to the host fish, they encyst inside the gill or fin tissue and continue to develop there. When they have developed enough, they excyst from the fin or gill tissue and drop to the bottom of the stream and continue to develop into mature mussels. ("Determination of Basic Reproductive Characteristics of the Winged Mapleleaf Mussel (Quadrula fragosa) Relevant to Recovery.", 2000; "Quadrula fragosa-Winged Mapleleaf", 2012; "Quadrula fragosa", 2013; "U.S Fish and Wildlife Service", 2013; Steingraeber, et al., 2007)
Winged mapleleaf mussels reproduce similarly to other fresh water mussels. The males release sperm into the water, which is then taken in by female mussels as they siphon in water. ("Determination of Basic Reproductive Characteristics of the Winged Mapleleaf Mussel (Quadrula fragosa) Relevant to Recovery.", 2000; "Quadrula fragosa-Winged Mapleleaf", 2012)
Fertilization of the sperm and egg occurs in the female, and the eggs remain there until they develop into glochidia, when it is then released into the stream. In regards to when winged mapleleaf broods, there are two different reports. One study found that they brooded during early September through early October, while another study found that they brooded between late May and July. According to some studies, the difference in brooding periods may be because Quadrula fragosa is being confused with the very similar Quadrula quadrula species which broods from April to August. Winged mapleleaf mussels reach sexual maturity when they are 5 or 6 years old, but some have been reported to reach sexual maturity at age 3. Females produce around 500,000 to several million eggs. ("Determination of Basic Reproductive Characteristics of the Winged Mapleleaf Mussel (Quadrula fragosa) Relevant to Recovery.", 2000; "Quadrula fragosa-Winged Mapleleaf", 2012; "Winged Mapleleaf Mussel (Quadrula fragosa) Recovery Plan", 1997)
Females exhibit significant parental investment in brooding the offspring for awhile before release. There is also investment in the production of the egg and sperm. After the glochidia are released, there is no further care. ("Determination of Basic Reproductive Characteristics of the Winged Mapleleaf Mussel (Quadrula fragosa) Relevant to Recovery.", 2000)
The winged mapleleaf's average lifespan is not known, though the oldest known individual of this species is 22 years old. ("U.S Fish and Wildlife Service", 2013)
Winged mapleleaf mussels spend most of their lives in the sediments and riffles of rivers in multi-species communities, called mussel beds. They can also be solitary, but it depends on where they excyst from their fish host and land in the river bed. They are predominately sedentary, but they can use their muscular foot to move around. The only known source of interaction that they have with each other is through reproduction. ("Quadrula fragosa-Winged Mapleleaf", 2012; "U.S Fish and Wildlife Service", 2013)
There is little known about how the winged mapleleaf mussel communicates or perceives its environment. It has no eyes and no ears, but it can be detect chemicals in the water. ("Quadrula fragosa-Winged Mapleleaf", 2012; "U.S Fish and Wildlife Service", 2013)
Winged mapleleaf mussels filter their food from the water. They eat protozoans, bacteria, algae, as well as phytoplankton and zooplankaton. There are also some studies that show that they eat detritus particles in the water. ("Quadrula fragosa-Winged Mapleleaf", 2012; "U.S Fish and Wildlife Service", 2013)
Winged mapleleaf mussels have no special defense against predators, however, they are rather small and have a hard shell. Predation of Quadrula fragosa is considered to be opportunistic, rather than selective predation, and the predators of this species include minks, raccoons, turtles, water birds, and muskrats. ("Population and Habitat Viability Assessment for the Winged Mapleleaf Mussel", 1998; "Quadrula fragosa-Winged Mapleleaf", 2012; "Winged Mapleleaf Mussel (Quadrula fragosa) Recovery Plan", 1997)
One of the ways Quadrula fragosa effects its ecosystem is through the parasitic relationship that its larvae have with specific species of fish. The host fish that the larva can attach to and survive on are the blue catfish, Ictalurus furcatus, or the channel catfish, Ictalurus punctatus. According to some studies the blue catfish is the most common host fish they use. Quadrula fragosa also serves as prey to a variety of mammals and other animals. ("Winged Mapleleaf Mussel (Quadrula fragosa) Recovery Plan", 1997; Hornbach, et al., 1996; Steingraeber, et al., 2007)
Winged mapleleaf mussels act as bioindicators. Since they are susceptible to pollution, their presence or absence in an ecosystem is a good indicator of the health of that ecosystem. ("Quadrula fragosa-Winged Mapleleaf", 2012; "Winged Mapleleaf Mussel (Quadrula fragosa) Recovery Plan", 1997)
There are no known adverse effects of Quadrula fragosa on humans.
The winged mapleleaf was thought to be extinct until a population of it was discovered in the 1980's in the St. Croix River. Then in 1991, the U.S Fish and Wildlife Service listed it as federally endangered species, and it is now protected. The factors that put this species at risk include low reproduction, potential zebra mussel infestation, variation in stream flow due to dams, and pollution and water quality deterioration. In Minnesota, a recovery plan for the winged mapleleaf was completed by the U.S. Fish and Wildlife Service, Wisconsin and Minnesota DNRs, and Macalaster College, which identified what steps need to be taken to help bring back this species. ("Winged Mapleleaf Mussel (Quadrula fragosa) Recovery Plan", 1997; Hornbach, et al., 1996; Steingraeber, et al., 2007)
Quinlan Eatwell (author), Minnesota State University, Mankato, Robert Sorensen (editor), Minnesota State University, Mankato, Angela Miner (editor), Animal Diversity Web Staff.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
union of egg and spermatozoan
a method of feeding where small food particles are filtered from the surrounding water by various mechanisms. Used mainly by aquatic invertebrates, especially plankton, but also by baleen whales.
mainly lives in water that is not salty.
An animal that eats mainly plants or parts of plants.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
fertilization takes place within the female's body
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death
photosynthetic or plant constituent of plankton; mainly unicellular algae. (Compare to zooplankton.)
an animal that mainly eats plankton
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
breeding is confined to a particular season
remains in the same area
non-motile; permanently attached at the base.
Attached to substratum and moving little or not at all. Synapomorphy of the Anthozoa
reproduction that includes combining the genetic contribution of two individuals, a male and a female
lives alone
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)
Wisconsin Department of Natural Resources. Determination of Basic Reproductive Characteristics of the Winged Mapleleaf Mussel (Quadrula fragosa) Relevant to Recovery.. Project E-1-27. Minnesota: United States Department of Interior Fish and Wildlife Service. 2000. Accessed March 23, 2013 at http://dnr.wi.gov/topic/fishing/documents/reports/stcroixmapleleafrepro2000.pdf.
U.S Fish and Wildlife Service. Population and Habitat Viability Assessment for the Winged Mapleleaf Mussel. Final Report: June 1998. Apple Valley, MN: U.S Fish and Wildlife Service. 1998. Accessed March 23, 2013 at http://www.cbsg.org/cbsg/workshopreports/23/wingedmapleleafmusselphva.pdf.
2013. "Quadrula fragosa" (On-line). Minnesota Department of Natural Resources. Accessed March 23, 2013 at http://www.dnr.state.mn.us/rsg/profile.html?action=elementDetail&selectedElement=IMBIV39050.
2012. "Quadrula fragosa-Winged Mapleleaf" (On-line). NatureServe Explorer. Accessed March 23, 2013 at http://www.natureserve.org/explorer/servlet/NatureServe?sourceTemplate=tabular_report.wmt&loadTemplate=species_RptComprehensive.wmt&selectedReport=RptComprehensive.wmt&summaryView=tabular_report.wmt&elKey=111959&paging=home&save=true&startIndex=1&nextStartIndex=1&reset=false&offPageSelectedElKey=111959&offPageSelectedElType=species&offPageYesNo=true&post_processes=&radiobutton=radiobutton&selectedIndexes=111959.
2013. "U.S Fish and Wildlife Service" (On-line). U.S Fish and Wildlife Service, Endangerd Species. Accessed March 23, 2013 at http://www.fws.gov/midwest/Endangered/clams/winge_fc.html.
U.S. Fish and Wildlife Service. Winged Mapleleaf Mussel (Quadrula fragosa) Recovery Plan. Written for Region 3, U.S. Fish and Wildlife Service. Ft. Snelling, Minnesota: U.S Fish and Wildlife Service. 1997. Accessed March 23, 2013 at http://www.fws.gov/midwest/mussel/documents/winged_mapleleaf_recovery_plan.pdf.
Hornbach, D., J. March, T. Deneka, N. Trolestrup, Jr, J. Perry. 1996. Factors Influencing the Distribution and Abundance of the Endangered Winged Mapleleaf Mussel Quadrula fragosa in the St. Croix River, Minnesota and Wisconsin. American Midland Naturalist, 136, No. 2: 278-286.
Steingraeber, M., M. Bartsch, J. Kalas, T. Newton. 2007. Thermal Criteria for Early Life Stage Development of the Winged Mapleleaf Mussel (Quadrula fragosa). American Midland Naturalist, 157: 297-311.