Red back salamander
|Red- backed salamander|
Salamandra cinerea Green, 1818
The red back (or redback or red-backed) salamander (Plethodon cinereus) is a small, hardy woodland salamander. It inhabits wooded slopes in eastern North America, west to Missouri, south to North Carolina, and north from southern Quebec and the Maritime Provinces in Canada to Minnesota. It is also known as the eastern red-backed salamander  or the northern red back salamander to distinguish it from the southern red back salamander (Plethodon serratus).
Description and ecology
The red back salamander is a small (5.7 to 10.0 cm) terrestrial salamander which usually lives in forested areas under rocks, logs, bark, and other debris. It is one of the most numerous salamanders throughout its range. The red back salamander exhibits color polymorphism and two color variations are common: the nominate 'red back' variety has a red dorsal stripe that tapers towards the tail, and the darker variety, known as the 'lead back phase', lacks most or all of the red pigmentation. The red back phase is not always red, but may actually be various other colors (e.g., stripe colored yellow, orange, white, or a rare erythristic morph, in which the body is completely red). Both morphs have speckled black and white bellies.
The skin of red back salamanders was found to contain Lysobacter gummosus, an epibiotic bacterium which produces the chemical 2,4-diacetylphloroglucinol and inhibits the growth of certain pathogenic fungi.
Antipredator behavior was found to differ between the two color phases; the lead back phase has a tendency to run away from predators, whereas the red back phase often stays immobile and possibly exhibits aposematic coloration. Stress levels of each color phase were estimated by determining the ratio of neutrophil to lymphocyte cells in the blood, and the results suggest stress levels are higher in the lead back phase than the red back variety. This may be a consequence of a higher predation risk experienced in the wild by the lead back phase, and may also mean the lead back phase salamanders could be more vulnerable in captivity settings.
Reproduction and biomass
Males and females typically establish separate feeding and/or mating territories underneath rocks and logs. However, some red back salamanders are thought to engage in social monogamy, and may maintain co-defended territories throughout their active periods. Breeding occurs in June and July. Females produce from four to 17 eggs in a year. The eggs will hatch in six to eight weeks. Not much is known about the dispersal of neonates, although neonates and juveniles are thought to be philopatric. The species largely consumes invertebrates and other detritus dwellers. In some areas with good habitat, these salamanders are so numerous, their population densities may surpass 1,000 individuals per acre.
Red back salamanders are popular pets because of their hardiness. Cages do not need to be exceptionally large, and a common sweater box may be used with small holes poked on the sides. The enclosure must have a secure lid, for red back salamanders are able to climb on smooth surfaces. They require driftwood and some sort of ground cover in them to keep the salamander feeling secure. The environment must be partially moist and kept out of direct sunlight or the salamander's skin will dry out and it will suffocate. Too much water can cause stress, especially when it forms pools (salamanders can swim but because of the lack of oxygen in water will drown if they cannot escape).
Ideal temperature for them would be 58 to 65 °F (14 to 18 °C), if it gets over 75 °F (24 °C), the salamander will either dry out and suffocate, or burrow very deeply. If the temperature reaches 35–50 °F (2–10 °C), they will start to hibernate, and below freezing they will die if they are not under ground. Staple diets consist of small black or red ants, small spiders, pinhead crickets, chopped earthworms, small mealworms or even other salamanders. Two red back salamanders not found together, when put in a small container with little food, can be cannibalistic, and they may eat their own eggs and hatchlings.
- Integrated Taxonomic Information System [Internet] 2012. [updated 2012 Sept; cited 2012 Nov 26] Available from: www.itis.gov
- Conant R, Collins JT. 1998. A field guide to reptiles and amphibians of eastern and central North America. Boston; Houghton Mifflin.
- Brucker RM, Baylor CM, Walters RL, Lauer A, Harris RN, Minbiole KPC. 2008. The identification of 2,4-diacetylphloroglucinol as an antifungal metabolite produced by cutaneous bacteria of the salamander Plethodon cinereus. Journal of Chemical Ecology 34(1):39-43.
- Venesky MD, Anthony CD. 2007. Antipredator adaptations and predator avoidance by two color morphs of the eastern red-backed salamander, Plethodon cinereus. Herpetologica 63(4):450-458.
- Davis AK, Milanovich JR. 2010. Lead-phase and red-stripe color morphs of red-backed salamanders Plethodon cinereus differ in hematological stress indices: A consequence of differential predation pressure? Current Zoology 56(2):238-243.
- APPALACHIAN NATURE: An Entree’ of Salamanders
Data related to Plethodon cinereus at Wikispecies
- Plethodon cinereus
- Parental Care in Plethodon cinereus
- Plethodon cinereus, Caudata Culture
- Eastern Redback Salamander (Plethodon cinereus), Natural Resources Canada
- The identification of 2,4-diacetylphloroglucinol as an antifungal metabolite produced by cutaneous bacteria of the salamander Plethodon cinereus