The Indiana bat is a medium-sized bat found in the Lead Belt region of southeastern Missouri; this bat is found in the Missouri counties of Iron, Shannon and Washington. When fully mature, Indiana bats are approximately 2 inches long and have a wingspan of 8 inches. These bats are endangered in Missouri since most of the state's caves are not cool enough; Indiana bats have only been found in 27 of Missouri's 6,500 caves. The primary causes for the Indiana bat's threatened status is the increase of pesticide use, water degradation and human encroachment.
Western prairie fringed orchids are found in less than 60 sites throughout the Midwest United States; most of these plants grow west of the Mississippi River. In Missouri, western prairie fringed plants are in the Northwest corner of the state. When mature, these plants have an approximate height of 4 feet. The major cause of endangerment for western prairie fringed orchids is habitat loss due to agricultural development, over collection and pesticides. Western prairie fringed orchids have been on the U.S. List of Endangered and Threatened Species since 1989.
The Curtis' pearly mussel is one of seven clam species on the U.S. List of Endangered and Threatened Species; the mussel was listed in 1976. In Missouri, these mussels are found in the southeastern region of the state on the banks of Little Black River, Can Creek and Castor River. Curtis' pearly mussels have yellowish shells and are less than 2 inches long. The building of large reservoirs in Southeast Missouri, including Lake Taneycomo and Bull Shoals Reservoir, are the primary reason for the decline in this mussel's population. Chemical pollution is another reason for endangerment of the Curtis' pearly mussel.
The only location to find pallid sturgeon, a fish species, is in the Missouri River and the Mississippi River. Pallid sturgeons are identified by their flat noses and rows of bones on the side of their bodies. These fish grow up to 5 feet in length and weigh up to 80 pounds when they mature; full maturation does not happen until after three to four years. Pallid sturgeons are known to have a natural lifespan of approximately 50 years. The major causes of population decline include commercial fishing, habitat fragmentation and water degradation.