Quadrula fragosa

Geographic Range

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.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

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.

• Habitat Regions
• temperate temperate
• freshwater freshwater

• Aquatic Biomes
• rivers and streams

Physical Description

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.

• Other Physical Features
• ectothermic ectothermic
• heterothermic heterothermic
• bilateral symmetry bilateral symmetry

Development

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.

• Development - Life Cycle
• metamorphosis metamorphosis

Reproduction

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.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

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.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
  • internal internal

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.

• Parental Investment
• pre-fertilization
  • provisioning
• pre-hatching/birth
  • provisioning
    • female

Lifespan/Longevity

The winged mapleleaf's average lifespan is not known, though the oldest known individual of this species is 22 years old.

Behavior

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.

• Key Behaviors
• sessile sessile
• motile motile
• sedentary sedentary
• solitary solitary

Communication and Perception

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.

• Perception Channels
• chemical chemical

Food Habits

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.

• Primary Diet
• herbivore herbivore
  • algivore
• planktivore planktivore

• Animal Foods
• zooplankton zooplankton

• Plant Foods
• algae
• phytoplankton phytoplankton

• Other Foods
• microbes

• Foraging Behavior
• filter-feeding filter-feeding

Predation

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.

Ecosystem Roles

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.

• Ecosystem Impact
• parasite parasite

Economic Importance for Humans: Positive

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.

• Positive Impacts
• research and education

Economic Importance for Humans: Negative

There are no known adverse effects of Quadrula fragosa on humans.

Conservation Status

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.

Additional Links

Encyclopedia of Life

BioKIDS Critter Catalog

Contributors

Quinlan Eatwell (author), Minnesota State University, Mankato, Robert Sorensen (editor), Minnesota State University, Mankato, Angela Miner (editor), Animal Diversity Web Staff.

References

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.

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 .