Mississippi Slimy Salamander
© 2010 Michael Graziano (1 of 17)
Country distribution from AmphibiaWeb's database: United States
Plethodon mississippi Highton, 1989
David A. Beamer1
1. Historical versus Current Distribution. Mississippi slimy salamanders (Plethodon mississippi) are distributed from southwestern Kentucky south through western Tennessee, eastern Mississippi, western Georgia, and southeastern Louisiana. The type specimens were described by Highton (1989) and collected at 177 m elevation. Their historical distribution is unknown, but likely to be similar to the current distribution.
2. Historical versus Current Abundance. Highton (2003) noted declines in Mississippi slimy salamanders in each of the eight populations he sampled prior to 1986, then resampled under similar conditions using similar effort in or after 1992. In six of these populations, declines were precipitous, with fewer than half the original number of animals detected in the more recent census. Additional monitoring will be required to determine whether these data reflect true declines or natural fluctuations.
3. Life History Features.
A. Breeding. Reproduction is terrestrial. In males from Louisiana, the testes are large from September–February. The vasa deferentia are enlarged from March–July. Spermatophores probably are formed in July–August (Highton, 1962b).
i. Breeding migrations. Undocumented, but breeding migrations are unknown for any Plethodon species.
ii. Breeding habitat. Unknown.
B. Eggs. Females collected in late June had heavily yolked eggs. Eggs probably are deposited in late summer (Highton, 1962b).
i. Egg deposition sites. Mississippi slimy salamanders from Wayne County, Mississippi, deposited their eggs in a cave (Brode and Gunter, 1958). Caves are not available for nesting in large portions of the range of Mississippi slimy salamanders; in these areas, other subterranean areas or rotting logs may be used as nesting sites.
ii. Clutch size. Seventeen eggs (5–8 mm diameter) were reported from a cave in Mississippi (Brode and Gunter, 1958).
C. Direct Development. Hatchlings have been found in a Mississippi cave from early August to September (Brode and Gunter, 1958). A juvenile that was likely a few months old was collected from Harrison County, Mississippi, and measured 17 mm (Highton, 1956).
i. Brood sites. Females have been found brooding their clutches in a cave in Mississippi (Brode and Gunter, 1958). Caves are not available for brooding in large portions of the range of Mississippi slimy salamanders; in these areas, other subterranean areas or rotting logs may be used as brood sites.
ii. Parental care. Females were found in attendance of their eggs in a Mississippi cave. Females remain with the hatchlings for 1–2 wk before the young disperse (Brode and Gunter, 1958).
D. Juvenile Habitat. Similar to adults. In a study of a Louisiana population, only a single juvenile was collected from December–February. It is likely they stay at the nest site for the first several months after hatching (Highton, 1962b).
E. Adult Habitat. Mississippi slimy salamanders are common in maritime forest and river bottom hardwood forests. Some of the area within the range of Mississippi slimy salamanders historically was covered with savanna and prairie, and in these areas they are rare or absent. Mississippi slimy salamanders do not require pristine habitats or old-growth forests and are often found under discarded rubbish. There may be a minimum size wood lot necessary, as they are absent from small wood lots (Lazell, 1994). In Mississippi, at Tishmingo State Park, Mississippi slimy salamanders are found in oak-hickory forest (Ferguson, 1961b). Mississippi slimy salamanders are reported from a cave in Lauderale County, Alabama (Peck, 1974).
F. Home Range Size. Unknown, but small home ranges are typical for Plethodon species.
G. Territories. At least some members of the Plethodon glutinosus complex aggressively defend territories (Thurow, 1976); it is unknown whether Mississippi slimy salamanders establish and defend territories.
H. Aestivation/Avoiding Dessication. Generally unknown, but Mississippi slimy salamanders likely avoid desiccating conditions by seeking shelter in underground sites.
I. Seasonal Migrations. Mississippi slimy salamanders are the most common salamander in Harrison County, Mississippi, during the winter but rarely are found during the summer (Allen, 1932). It is likely that Mississippi slimy salamanders move vertically from forest-floor sites to underground sites in response to seasonal dry and cold conditions.
J. Torpor (Hibernation). Generally unknown, but Mississippi slimy salamanders likely avoid cold conditions by seeking shelter in underground sites.
K. Interspecific Associations/Exclusions. The following salamanders, along with Mississippi slimy salamanders, are all reported from Tishmingo County, Mississippi: marbled salamanders (Ambystoma opacum), spotted dusky salamanders (Desmognathus conanti), southern zigzag salamanders (Plethodon ventralis), spring salamanders (Gyrinophilus porphyriticus), red salamanders (Pseudotriton ruber), green salamanders (Aneides aeneus), southern two-lined salamanders (Eurycea cirrigera), long tailed salamanders (E. longicauda), and cave salamanders (E. lucifuga; Ferguson, 1961b; Wake and Woods, 1968).
In the vicinity of the presumed type locality of Bay Springs salamanders (Plethodon ainsworthi), Mississippi slimy salamanders are found with red salamanders, southern dusky salamanders (Desmognathus auriculatus), southern two-lined salamanders, and three-lined salamanders (Eurycea guttolineata; D.A.B., personal observations).
L. Age/Size at Reproductive Maturity. The holotype is an adult male, 65 mm SVL; the allotype is an adult female 71 mm. The smallest mature female from Louisiana was 42 mm, the smallest mature male 37 mm (Highton, 1962b).
Louisiana populations of Mississippi slimy salamanders probably reach maturity in 2 yr and breed for the first time at age 3. In both Louisiana and Mississippi at least some females may breed biannually (Highton, 1956, 1962b).
M. Longevity. Unknown.
N. Feeding Behavior. Unknown, but as with other Plethodon species, feeding likely takes place at night under moist conditions. Prey items likely include a range of invertebrates, especially insects.
O. Predators. Undocumented, but likely to include forest snakes, birds, and small mammals.
P. Anti-Predator Mechanisms. Nocturnal. All members of the genus Plethodon produce noxious skin secretions (Brodie, 1977). Individuals will vocalize when physically disturbed (Marshall, 1997). Members of the Plethodon glutinosus complex frequently become immobile when initially contacted. Mississippi slimy salamanders were included in a field study on immobility; however, it is not possible to separate their behavior from the other members of this complex in this published data set. Immobility may increase survival by making the salamander less likely to be detected, especially by visually oriented predators (Dodd, 1989).
Q. Diseases. Unknown.
R. Parasites. Unknown.
4. Conservation. Among members of the P. glutinosus complex, Mississippi slimy salamanders have one of the widest distributions and they are not protected by any state. Within their range there are several federal and state properties that contain suitable habitat for these salamanders.
Mississippi slimy salamanders are relatively resilient to disturbances, such as those associated with timbering operations, and are found frequently in second-growth forests and relatively small, fragmented woodlots (Lazell, 1994; D.A.B., personal observations).
As with all species of Plethodon, Mississippi slimy salamanders do not migrate and have small home ranges. Thus, they can exist in habitats of smaller size than many other amphibian species. However there may be a minimum habitat size necessary, as they are absent from small wood lots (Lazell, 1994). Conservation activities that promote mature closed-canopy forests should benefit this species.
Acknowledgments. Thanks to Richard Highton, who reviewed this account and gave us the benefit of his insight and experience.
1David A. Beamer1
2Michael J. Lannoo2
Literature references for Amphibian Declines: The Conservation Status of United States Species, edited by Michael Lannoo, are here.
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Citation: AmphibiaWeb. 2019. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 24 Mar 2019.
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