Apalachicola Bay is an estuary and lagoon located on the northwest coast of the U.S. state of Florida. The Apalachicola Bay system also includes St. George Sound, St. Vincent Sound and East Bay, covering an area of about 208 square miles (540 km2). Four islands, St. Vincent Island to the west, Cape St. George Island and St. George Island to the south, and Dog Island to the east, separate the system from the Gulf of Mexico. Water exchange occurs through Indian Pass, West Pass, East Pass and the Duer Channel. The lagoon has been designated as a National Estuarine Research Reserve and the Apalachicola River is the largest source of freshwater to the estuary. Combined with the Chattahoochee River, Flint River, and Ochlockonee River they drain a watershed of over 20,000 square miles (50,000 km2) at a rate of 19,599 cubic feet per second according to the United States Geological Survey in 2002.
Unio crassus, the thick shelled river mussel, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
The freshwater pearl mussel is an endangered species of freshwater mussel, an aquatic bivalve mollusc in the family Margaritiferidae.
The Appalachian elktoe is a species of freshwater mussel in the family Unionidae, the river mussels. It is native to the United States, where it is known only from North Carolina and Tennessee.
Cumberlandia monodonta is a freshwater mussel endemic to the United States. Currently, C. monodonta is listed as an endangered species by the U.S. Fish and Wildlife Service and the International Union for Conservation of Nature.
Dromus dromas, the dromedary pearlymussel or dromedary naiad, is a rare species of freshwater mussel in the family Unionidae. This aquatic bivalve mollusk is native to the Cumberland and Tennessee River systems in the United States, where it has experienced a large population decline. It is a federally listed endangered species of the United States.
The Chipola slabshell is a part of the phylum Mollusca and the class Bivalvia. This species has suffered a large decrease with upwards of 75% of habitat lost. It is now confined to only a few remnant sites in small drainages within the Chipola River. The federal Endangered Species Act protects it as a designated threatened species by Florida’s Endangered and Threatened Species Rule.
Elliptio spinosa, the Altamaha spinymussel, is an endangered species of freshwater mussel in the family Unionidae. They live in southeastern Georgia in the Altamaha river and its tributaries. It is one of three species of North American spinymussels which are recognizable by their prominent spines. The Altamaha spinymussel genetically diverged from the other spinymussels 3.76 million years ago. This suggests that their spines evolved separately from the spines of other North American spinymussels. The Altamaha spinymussel is on the Endangered Species Act because of many threats with the most prominent threats being habitat loss, decrease in water quality, shrinking range, small population size, and vulnerability to disturbances.
The Cumberlandian Combshell is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae. This species is endemic to the United States, found mainly in the states of Tennessee and Virginia. This mussel resides in medium-sized streams to large rivers. The combshell is an endangered species and protected under the Endangered Species Act of 1973. The combshell is threatened by habitat modifications and pollution.
Fusconaia escambia, the narrow pigtoe, is a freshwater bivalve mussel found in Alabama and northwestern Florida. The narrow pigtoe was first discovered in the Escambia River in Alabama and Florida.
Lampsilis higginsii is a rare species of freshwater mussel known as Higgins' eye pearly mussel or simply Higgins' eye. It is endemic to the United States, where it occurs in the upper Mississippi River and the drainages of some of its tributaries. It is threatened by the introduced zebra mussel. Lapsilis higginsii is a federally listed endangered species.
Lampsilis rafinesqueana, the Neosho mucket or Neosho pearly mussel, is a species of North American freshwater mussel endemic to Arkansas, Oklahoma, Illinois, Missouri and Kansas.
The Carolina heelsplitter is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae.
Medionidus acutissimus, the Alabama moccasinshell, is a species of freshwater mussel in the family Unionidae, the river mussels. It is native to Alabama, Mississippi, Georgia, Tennessee, and possibly Florida. It is a federally listed threatened species of the United States.
Medionidus penicillatus, the gulf moccasinshell, is a rare species of freshwater mussel in the family Unionidae, the river mussels. This aquatic bivalve mollusk is native to Alabama, Florida, and Georgia in the United States, where it is in decline and has been extirpated from most of the rivers it once inhabited. It is a federally listed endangered species of the United States.
Obovaria retusa is a rare species of freshwater mussel in the family Unionidae, the river mussels. Its common names include golf stick pearly mussel
The oval pigtoe is a federally endangered species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
Potamilus capax, the fat pocketbook pearly mussel or fat pocketbook, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
The winged mapleleaf, also known as false mapleleaf, or hickory nut shell, and with the scientific name Quadrula fragosa, is a species of freshwater mussel. It is an aquatic bivalve mollusk in the family Unionidae, the river mussels. It is endemic to the United States.
The Halloween darter is a small freshwater fish native to North America. It is found in Georgia and Alabama in the drainage basin of the Apalachicola River, specifically in the Flint River system and the Chattahoochee River system. It prefers shallow, fast-flowing areas with gravel bottoms in small and medium-sized rivers. It was first described in 2008, having not previously been distinguished from the blackbanded darter (P. nigrofasciata), formerly though to occur in the same watershed, which has since been split again with Westfall's darter now recognised from the Apalachicola drainage. The species is somewhat variable, being generally blackish dorsally, with some individuals having indistinct saddle-like barring. Males have orange and dark lateral striping while females have dark stripes and a yellowish-green belly. At a maximum standard length of 101 mm (4 in), males are slightly larger than females, and both sexes develop distinctive orange barring on the edge of the first dorsal fin during the breeding season.
