Plicate rocksnail | |
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1842 drawing of the shell of Leptoxis plicata by Jean-Charles Chenu. | |
Scientific classification ![]() | |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Gastropoda |
Subclass: | Caenogastropoda |
Family: | Pleuroceridae |
Genus: | Leptoxis |
Species: | L. plicata |
Binomial name | |
Leptoxis plicata | |
Synonyms | |
Anculotus plicatus Conrad, 1834 Anculotus plicata Conrad Contents |
The plicate rocksnail, scientific name Leptoxis plicata, is a species of freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Pleuroceridae.
This species is endemic to the United States, specifically the state of Alabama. The snail has been listed as endangered on the United States Fish and Wildlife Service list of endangered species since October 28, 1998. [3]
The plicate rocksnail is a pleurocerid snail with a shell that grows to about 20 mm (0.8 in) in length. Shells are subglobose with broadly rounded apertures. The body whorl may be ornamented with strong folds or plicae. Shell color is usually brown, occasionally green, and often with four equidistant color bands. The columella (central column or axis) is smooth, rounded, and typically pigmented in the upper half. The aperture is usually bluish-white, occasionally pink or white. [4]
The operculum (plate that closes the shell when the snail is retracted) is dark red, and moderately thick. [4] [5]
Although morphologically similar to the basin's other three surviving rocksnail species, the plicate rocksnail is genetically distinct. [4] [6]
The plicate rocksnail historically occurred in the Black Warrior River, the Little Warrior River, and the Tombigbee River. [4] [5]
Recent status surveys have located plicate rocksnail populations only in an approximately 88 km (55 mi) reach of the Locust Fork of the Black Warrior River, Jefferson and Blount counties, Alabama. [7] The latest survey information indicates that the snail has recently disappeared from the upstream two-thirds portion of that habitat and now appears to be restricted to an approximately 32 km (20 mi) reach in Jefferson County. [4] [8] [9]
The plicate rocksnail has disappeared from more than 90 percent of its historic range. The curtailment of habitat and range for this species (and a few other snail species) in the Mobile Basin's larger rivers – (Black Warrior River, the Little Warrior River, and the Tombigbee River for the plicate rocksnail) is primarily due to extensive construction of dams, and the subsequent inundation of the snail's shoal habitats by the impounded waters. This snail has disappeared from all portions of its historic habitats that have been impounded by dams. [4]
Dams change such areas by eliminating or reducing currents, and thus allowing sediments to accumulate on inundated channel habitats. Impounded waters also experience changes in water chemistry, which could affect survival or reproduction of riverine snails. For example, many reservoirs in the Basin currently experience eutrophic (enrichment of a water body with nutrients) conditions, and chronically low dissolved oxygen levels. [10] [11] Such physical and chemical changes can affect feeding, respiration, and reproduction of these riffle and shoal snail species. [4]
Plicate rocksnails inhabit shallow gravel and cobble shoals in the flowing waters of rivers. [4]
Although the precise longevity has not been well documented, individuals have survived 2 years in captivity. [12]
The Mobile River is located in southern Alabama in the United States. Formed out of the confluence of the Tombigbee and Alabama rivers, the approximately 45-mile-long (72 km) river drains an area of 44,000 square miles (110,000 km2) of Alabama, with a watershed extending into Mississippi, Georgia, and Tennessee. Its drainage basin is the fourth-largest of primary stream drainage basins entirely in the United States. The river has historically provided the principal navigational access for Alabama. Since construction of the Tennessee-Tombigbee Waterway, it also provides an alternative route into the Ohio River watershed.
The snail darter is a small species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It is found in East Tennessee freshwater in the United States and in small portions of northern Alabama and Georgia. First recorded in 1973, the snail darter was listed as endangered under the U.S. Endangered Species Act of 1973 by 1975. The species was at the center of a major environmental law controversy that involved a lawsuit seeking to halt the completion of Tellico Dam, which posed a risk of extinction for the snail darter by blocking its migratory route. The case was eventually appealed to the U.S. Supreme Court, which ruled on it in its 1978 decision Tennessee Valley Authority v. Hill.
The Cahaba River is the longest substantially free-flowing river in Alabama and is among the most scenic and biologically diverse rivers in the United States. It is a major tributary of the Alabama River and part of the larger Mobile River basin. With headwaters near Birmingham, the Cahaba flows southwest, then at Heiberger turns southeast and joins the Alabama River at the ghost town and former Alabama capital of Cahaba in Dallas County. Entirely within central Alabama, the Cahaba River is 194 miles (312 km) long and drains an area of 1,870 square miles (4,800 km2). The name Cahaba is derived from the Choctaw words oka meaning "water" and aba meaning "above"
The black-knobbed map turtle, formerly known as the black-knobbed sawback, is a small to medium-sized aquatic turtle with light gray skin. Some of the most distinguishing characteristics of the black-knobbed map turtle, and the Graptemys genus, are the protruding "spikes" on the turtle's carapace. This species inhabits mainly the fall lines of rivers in the Mobile Bay drainage, in Alabama and Mississippi.
The frecklebelly madtom is a species of fish in the family Ictaluridae endemic to the United States. Madtoms are in the genus Noturus, which is a group of catfish prevalent in North America. In 2023, the Upper Coosa River distinct population segment (DPS) of N. munitus was listed as federally threatened under the Endangered Species Act of 1973.
The lacy elimia also known as the lacey elimia, scientific name Elimia crenatella, is a species of freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Pleuroceridae.
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.
Leptoxis ampla, common name the round rocksnail, is a species of freshwater snail with a gill and an operculum, an aquatic gastropod mollusc in the family Pleuroceridae.
Leptoxis is a genus of freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the family Pleuroceridae.
Leptoxis clipeata, the agate rocksnail, was a freshwater snail in the family Pleuroceridae. Like all Leptoxis, the species required free-flowing unpolluted water. It was endemic to parts of the Coosa River in Alabama, now impounded.
Leptoxis compacta, the oblong rocksnail, is a species of freshwater snail with an operculum, an aquatic gastropod mollusk in the family Pleuroceridae.
Leptoxis foremani, the interrupted rocksnail, is a species of freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Pleuroceridae.
The painted rocksnail is a species of freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Pleuroceridae.
The flat pebblesnail is a species of freshwater snail, an aquatic gastropod mollusk in the family Lithoglyphidae.
The cylindrical lioplax, scientific name Lioplax cyclostomaformis, is a species of freshwater snail with gills and an operculum, an aquatic gastropod mollusk in the family Viviparidae.
Pleurobema taitianum, the heavy pigtoe or Judge Tait's mussel, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
The rough hornsnail, scientific name Pleurocera foremani, is a rare species of freshwater snail with an operculum, an aquatic gastropod mollusk in the family Pleuroceridae.
Elimia showalteri, common name the compact elimia, is a species of freshwater snail with an operculum, an aquatic gastropod mollusc in the family Pleuroceridae.
The Mobile logperch is a species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It is found in the Mobile River basin in Mississippi, Alabama, Tennessee, and Georgia in the southeastern United States. It inhabits clear shallow water and is often associated with Podostemum (riverweed). It grows to about 18 cm (7 in) and is distinguishable from other darters by the distinctive shape of its head and by its pale-yellow base color, with narrow bars on back and sides. It feeds on small invertebrates and breeds between February and May. Lake fish move into small streams to spawn. It is a common fish with a wide range and the International Union for Conservation of Nature has classified its conservation status as being of "least concern".
This article incorporates public domain text (a public domain work of the United States Government) from the reference. [4]