Pyramidula alternata var. eriensis G. H. Clapp, 1916
Anguispira alternata f. angulata Pilsbry, 1948
Anguispira alternata var. palustris B. Walker, 1928
Helix alternata var. costata J. Lewis, 1871
Pyramidula alternata costata (J. Lewis, 1871)
Pyramidula alternata var. costata (J. Lewis, 1871)
Anguispira alternata var. alba Tryon, 1866
Pyramidula alternata var. alba (Tryon, 1866)
Helix inflecta L. Pfeiffer, 1858
Helix alternata var. carinata A. Férussac, 1832
Corocolla dubia Sheppard, 1829
Helix scabra Lamarck, 1822
Anguispira alternata, also known as the flamed disc or flamed tigersnail, is a species of pulmonateland snail in the familyDiscidae, the disk snails. It is the most common and widespread member of the Anguispira genus, and one of the more common land snail species in North America.[3]
Appearance and anatomy
Flamed tigersnails are medium-sized snails with shells ranging from 17 to 25 millimeters (0.67 to 0.98 inches) in diameter. On average, adults have a diameter of 20 mm (0.79 in) and a height of 12 mm (0.47 in).[4] The shell is a depressed heliciform with a rounded, thin-lipped aperture and 5-6 whorls.[5][6] The base of the shell is pale yellow to brown, and defined by irregular reddish or brown splotches. There are faint radial streaks extending to the base of the shell and a belt of spots below the periphery. It is covered in rib-like striae and the surface is very lightly wrinkled. The embryotic whorl is light gray and smooth. The snail's appearance can vary across its range. MalacologistHenry A. Pilsbry claimed that snails in mountainous or rocky regions tend to have more angular and heavily ribbed shells while snails in lowland areas are more rounded and smooth.[5][4]
Flamed tigersnails have two pairs of tentacles with eyes on the tips of the upper tentacles (or eyestalks). The body can range from a grayish brown to brownish black with a pale foot. The mucus the snail secretes is typically orange or reddish in color.[4][7][8] When the snail retracts inside of its shell, the anterior side of the body is pulled outside-in. The species' average resting heart beat ranges from 37 to 60 beats per minute, but can reach 90+ beats per minute when active.[3]
Apical view of the shell
Umbilical view of the shell
Reproduction
The flamed tigersnail is hermaphroditic but not viviparous. The eggs the species lays tend to range from 2 to 3 mm (0.08 to 0.12 in) in diameter, are ovate, white in color, and have a gelatinous coating that likely acts as protection. Eggs can be laid alone or in clusters, and typically take 30 to 45 days to hatch. Hatching time can vary based on moisture, temperature and other factors.[4] The flamed tigersnail does not have a love dart.[3]
The flamed tigersnail is fairly adaptable and found in a wide range of habitats. They are most commonly found in forests or glades near streams, climbing on trees, limestoneoutcrops, or buried in leaf litter.[1] However, they can also be found along roadsides, in vacant lots, and other urban settings.[9] One study estimated that flamed tigersnails have an average home range of 40 sq meters (430.56 sq ft).[10] Flamed tigersnails tend to live in groups, commonly burrowing and hibernating together during winter months. In Kansas, snails were observed living in groups of ranging from 16 to 75 snails per foot.[11] Scientists have documented the species climbing on trees at night, presumably to eat bark-dwelling algae.[6][3] It is unknown if they favor any specific species of tree, but one population was documented most frequently climbing on American beech trees.[9] Generally, flamed tigersnails are herbivores that feed on decaying plant material, fungi, and algae.[4]
^ abcdDouglas, Charles L. “Population Analyses, Variation and Behavior of Anguispira Alternata Alternata.” Transactions of the Kansas Academy of Science (1903-), vol. 66, no. 2, 1963, pp. 186–94. JSTOR, https://doi.org/10.2307/3626559. Accessed 9 Nov. 2024.
