Winged mapleleaf
Encyclopedia
The Winged Mapleleaf
The Winged Mapleleaf (Also known as False Mapleleaf, or Hickory Nut Shell (scientific name Quadrula Fragosa) is a species
of freshwater mussel, an aquatic
bivalve mollusk in the family Unionidae
, the river mussels.
This species of river mussel is endangered. It is found in the United States
.
mussel that is only located in a few parts of the Midwestern states of the continental United States. The anterior end of its shell is slightly rounded and the posterior end of the shell is more of a square shape.
The shell can range in color from a yellowish-green to light or dark brown. The inside of the shell is white, and there is sometimes iridescent coloring at one end of the shell. The diameter of a mature mussel of this species is usually about 4 inches (10.2 cm).
The shells of these mussels are very thick, and unlike many other mussels, there are bumps on the shell surface running down from the hinge of the shell to the outside edges. It is the patterns of these bumps that help to distinguish the winged mapleleaf from many other mussels that look very similar in appearance.
. It was once also found in some rivers and streams that flow into the Missouri River
.
Today however, the mussel can only be found in four rivers in the Midwestern United States, and only found in limited areas of those four rivers: in a five-mile stretch of the St. Croix River, which flows between the states of Minnesota
and Wisconsin
; In Arkansas
it can be found in the Ouachita River
and also the Saline River
, and some populations have been located in the Bourbeuse River
in Missouri
. Of these 4 locations, The population of these mussels in the St. Croix River is the only one that has been proven to actually be reproducing and growing in population. The mussels in the other 3 locations have no evidence that their populations are growing or that there is actually offspring is being produced. It is currently estimated that there is somewhere between 50-1000 individuals that are still alive today.
and the Blue catfish
.
The larva continue growing on the host fish until they reach their next life cycle stage, and once this stage is reached they are released from the gills of the host fish and find their way to the bottom of the river or stream. Once they have reached the bottom, they then begin maturing into the adult stage of their life cycle. The actual reason for the Channel catfish and the Blue catfish being the only host fish to successfully have a larva mature on them is still unknown.
Research was even done by a group of researchers where they used divers to see if they could plant the larva from the mother onto the gills of fish other than the two kinds of catfish. The research was limited from a number of different causes, a limited number of eggs found in the area to transplant on to captive fish, and also the deal of many of the fish that they had captive. The results, however they were very limited, still only showed the Channel and the Blue catfish to be successful host fish for the winged mapleleaf. The oldest known organism in this species is in the St. Croix River and is estimated to be 22 years old, although, the life span of the mussel is actually unknown.
Dreissena polymorpha, (which the U.S. Fish and Wildlife Service trying to control) is one the biggest threats to the survival of the winged mapleleaf. The Zebra mussel is an extremely invasive species and in 2000 the Zebra mussel began being a problem in the St. Croix River. Sediment accumulation and loss of water quality are also major threats to the population of the mussel.
The reproducing population in the St. Croix River area is near the metropolitan area of St. Paul, and as the larger cities begin to become further developed, sediment is dispersed into the river and more and more pollution occurs. This can also change the flow of the river, causing erosion and a change in water levels. The winged mapleleaf needs to be in a clean environment and can only survive in certain water levels.
Upstream dam operations also cause changes in the water level, which is another issue that the U.S. Fish and Wildlife Service is trying to take action towards. The biggest issue that the mussel currently faces right now is that there is only one known reproducing population. This means that a severe rainstorm that caused flooding, a pollution spill, or the outbreak of an upstream dam could easily wipe out the entire population and cause this mussel species to become extinct.
There is also currently an experimental population of the winged mapleleaf that has been released into the wild. This experimental population was released in parts of the Tennessee River in Colbert and Lauderdale counties. Whether or not these released populations are reproducing, has yet to be proven.
Many of the upstream dam operations have also began to be more closely monitored in order to ensure that there is an adequate flow of water in the St. Croix River for the winged mapleleaf to survive and reproduce. The levels of the river are being kept between the constant 0.4 and 2.0 meters that the mussel needs in order to survive.
U.S. Fish and Wildlife Service. [Washington, D.C.] : U.S. Fish and Wildlife Service, [2004] Online Access
U.S. Fish and Wildlife Service. [Washington, D.C.] : U.S. Fish and Wildlife Service, [2001] Online Access
Upper Midwest Environmental Sciences Center (Geological Survey). La Crosse, Wis. : U.S. Dept. of the Interior, U.S. Geological Survey, Upper Midwest Environmental Sciences Center, [2005] Online Access
The Winged Mapleleaf (Also known as False Mapleleaf, or Hickory Nut Shell (scientific name Quadrula Fragosa) is a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of freshwater mussel, an aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
bivalve mollusk in the family Unionidae
Unionidae
Unionidae is a family of freshwater mussels, the largest in the order Unionoida, the bivalve mollusks sometimes known as river mussels, naiads, or simply as unionids.The range of distribution for this family is world-wide...
, the river mussels.
This species of river mussel is endangered. It is found in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Description
Quadrula fragosa is a federally endangeredEndangered Species Act
The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...
mussel that is only located in a few parts of the Midwestern states of the continental United States. The anterior end of its shell is slightly rounded and the posterior end of the shell is more of a square shape.
The shell can range in color from a yellowish-green to light or dark brown. The inside of the shell is white, and there is sometimes iridescent coloring at one end of the shell. The diameter of a mature mussel of this species is usually about 4 inches (10.2 cm).
The shells of these mussels are very thick, and unlike many other mussels, there are bumps on the shell surface running down from the hinge of the shell to the outside edges. It is the patterns of these bumps that help to distinguish the winged mapleleaf from many other mussels that look very similar in appearance.
Habitat
The winged mapleleaf is found in medium to large streams and rivers. it can sometimes be found in the mud, but it is more commonly either found in gravel or sandy bottoms. The mussel does need to be in moving water in order to survive, the depth of this running water also needs to be somewhere between 0.4 to 2.0 meters. The water must be free of pollutants and clean.Range
At one time the winged mapleleaf could be found in thirteen states. It lived in nearly all the rivers and streams that flow into the Mississippi RiverMississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...
. It was once also found in some rivers and streams that flow into the Missouri River
Missouri River
The Missouri River flows through the central United States, and is a tributary of the Mississippi River. It is the longest river in North America and drains the third largest area, though only the thirteenth largest by discharge. The Missouri's watershed encompasses most of the American Great...
.
Today however, the mussel can only be found in four rivers in the Midwestern United States, and only found in limited areas of those four rivers: in a five-mile stretch of the St. Croix River, which flows between the states of Minnesota
Minnesota
Minnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...
and Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
; In Arkansas
Arkansas
Arkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...
it can be found in the Ouachita River
Ouachita River
The Ouachita River is a river that runs south and east through the U.S. states of Arkansas and Louisiana, joining the Tensas River to form the Black River near Jonesville, Louisiana.-Course:...
and also the Saline River
Saline River (Ouachita River)
The Saline River is a tributary of the Ouachita River in the south central portion of the U.S. state of Arkansas.The Saline River begins in the eastern foothills of the Ouachita Mountains in Saline and Garland counties and is one of the last free-flowing rivers in the Ouachita River Basin...
, and some populations have been located in the Bourbeuse River
Bourbeuse River
The Bourbeuse River is a river located in east-central Missouri, in the Ozarks region, and is one of two major tributaries of the Meramec River, the other being the Big River...
in Missouri
Missouri
Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...
. Of these 4 locations, The population of these mussels in the St. Croix River is the only one that has been proven to actually be reproducing and growing in population. The mussels in the other 3 locations have no evidence that their populations are growing or that there is actually offspring is being produced. It is currently estimated that there is somewhere between 50-1000 individuals that are still alive today.
Feeding
The mussel filters out tiny food particles, either phytoplankton or zooplankton. The young winged mapleleafs attach themselves to the gills of a host fish for feeding and growing purposes until they reach the stage in their life cycle that they can themselves siphon in the water from the river of the stream that they are in.Reproduction
Reproduction of the winged mapleleaf is very similar to that of many other freshwater mussels. The males release their sperm into the water, then as the females siphon in water the sperm fertilizes the eggs which are located on their gills. After fertilization the eggs develop in to a larva, and once the larva reaches a certain stage it is released from the gills of the mother mussel into the river current. The larva then must reach the gills of a host fish where it can then continue its growing process. The only currently known host fish are the Channel catfishChannel catfish
Channel catfish, Ictalurus punctatus, is North America's most numerous catfish species. It is the official fish of Missouri, Iowa, Nebraska, Kansas, and Tennessee, and is informally referred to as a "channel cat". In the United States they are the most fished catfish species with approximately 8...
and the Blue catfish
Blue catfish
The blue catfish, Ictalurus furcatus, is one of the largest species of North American catfish. Blue catfish are distributed primarily in the Mississippi River drainage including the Missouri, Ohio, Tennessee, and Arkansas rivers...
.
The larva continue growing on the host fish until they reach their next life cycle stage, and once this stage is reached they are released from the gills of the host fish and find their way to the bottom of the river or stream. Once they have reached the bottom, they then begin maturing into the adult stage of their life cycle. The actual reason for the Channel catfish and the Blue catfish being the only host fish to successfully have a larva mature on them is still unknown.
Research was even done by a group of researchers where they used divers to see if they could plant the larva from the mother onto the gills of fish other than the two kinds of catfish. The research was limited from a number of different causes, a limited number of eggs found in the area to transplant on to captive fish, and also the deal of many of the fish that they had captive. The results, however they were very limited, still only showed the Channel and the Blue catfish to be successful host fish for the winged mapleleaf. The oldest known organism in this species is in the St. Croix River and is estimated to be 22 years old, although, the life span of the mussel is actually unknown.
Threats
The winged mapleleaf currently faces a number of different threats to its survival. The invasion of the Zebra musselZebra mussel
The zebra mussel, Dreissena polymorpha, is a small freshwater mussel. This species was originally native to the lakes of southeast Russia being first described in 1769 by a German zoologist Peter Simon Pallas in the Ural, Volga and Dnieper rivers. They are still found nearby, as Pontic and Caspian...
Dreissena polymorpha, (which the U.S. Fish and Wildlife Service trying to control) is one the biggest threats to the survival of the winged mapleleaf. The Zebra mussel is an extremely invasive species and in 2000 the Zebra mussel began being a problem in the St. Croix River. Sediment accumulation and loss of water quality are also major threats to the population of the mussel.
The reproducing population in the St. Croix River area is near the metropolitan area of St. Paul, and as the larger cities begin to become further developed, sediment is dispersed into the river and more and more pollution occurs. This can also change the flow of the river, causing erosion and a change in water levels. The winged mapleleaf needs to be in a clean environment and can only survive in certain water levels.
Upstream dam operations also cause changes in the water level, which is another issue that the U.S. Fish and Wildlife Service is trying to take action towards. The biggest issue that the mussel currently faces right now is that there is only one known reproducing population. This means that a severe rainstorm that caused flooding, a pollution spill, or the outbreak of an upstream dam could easily wipe out the entire population and cause this mussel species to become extinct.
Extinction Preventions
The winged mapleleaf was added to the list of endangered and threatened plants and animals on July 22, 1991. It is now illegal to collect, harm, threaten, or kill the mussel. Permits can be issued from the U.S. Fish and Wildlife Service to give individuals rights to collect some individuals to conduct research projects, but these permits are not easily attained. The State of Wisconsin and the state of Minnesota are working with the help of the U.S. Fish and Wildlife Service to try to control the invasion of the Zebra mussel.There is also currently an experimental population of the winged mapleleaf that has been released into the wild. This experimental population was released in parts of the Tennessee River in Colbert and Lauderdale counties. Whether or not these released populations are reproducing, has yet to be proven.
Many of the upstream dam operations have also began to be more closely monitored in order to ensure that there is an adequate flow of water in the St. Croix River for the winged mapleleaf to survive and reproduce. The levels of the river are being kept between the constant 0.4 and 2.0 meters that the mussel needs in order to survive.
Source
- Bogan, A.E. & Seddon, M.B. 1996. Quadrula fragosa. 2006 IUCN Red List of Threatened Species. Downloaded on 7 August 2007.
- Bauer, Gerhard. Ecology and Evolution of the Freshwater Mussels. 2001. Springer Publishing
- Steingraber,Mark. U.S. fish and wildlife Service. Fort Snelling, MN http://www.fws.gov/midwest/LaCrosseFisheries/projects/mapleleaf.html
- Endangered species facts [electronic resource] : winged mapleleaf Electronic books
U.S. Fish and Wildlife Service. [Washington, D.C.] : U.S. Fish and Wildlife Service, [2004] Online Access
- Endangered species facts [electronic resource] Electronic books
U.S. Fish and Wildlife Service. [Washington, D.C.] : U.S. Fish and Wildlife Service, [2001] Online Access
- Host fish identification and early life thermal requirements for the federal endangered winged mapleleaf mussel [electronic resource] Electronic books
Upper Midwest Environmental Sciences Center (Geological Survey). La Crosse, Wis. : U.S. Dept. of the Interior, U.S. Geological Survey, Upper Midwest Environmental Sciences Center, [2005] Online Access
- Hornback, Daneil; March, James; Deneka, Tony; Troelstrup, Nels; Perry, James. "Factors Influencing the Distribution and Abundance of the Endangered Winged Mapleleaf Mussel Quadrula fragos in the St. Croix River, Minnesota and Wisconsin." American Midland Naturalist Volume 136.October, 1996 278-286. Accessed April 15, 2008
- Bleam, Daniel, Cope, Charles; Couch, Karen; Distler, Donald. "The Winged Mapleleaf, Quadrula fragosa in Kansas." Transaction of the Kansas Academy of Science Volume 101(1998) 35-38. April 17, 2008
- Steingraeber, Mark, Bartsch, Michelle; Kalas, John; Newton, Teresa. "Thermal Criteria for Early Life Stage Development of the Winged Mapleleaf Mussel (Quadrula fragosa).." American Midland Naturalist 157(2006) 297-311. April 17, 2008