The effect of predator kairomones on caudal regeneration by Allegheny Mountain Dusky Salamanders (Desmognathus ochrophaeus)

Abstract

Many prey use autotomy as an antipredator mechanism. Rapid regeneration of autotomized appendages is beneficial because forfeited tissues may serve as organs for energy storage, accessories for locomotion, or indicators of social status. We monitored levels of caudal regeneration by Allegheny Mountain Dusky Salamanders (Desmognathus ochrophaeus Cope, 1859) exposed to kairomones from predatory Eastern Garter Snakes (Thamnophis sirtalis (Linnaeus, 1758)). After the induction of autotomy, salamanders were exposed to one of three treatment regimens: blank (water), or acute (30 min per week) or chronic (constant) exposure to predator kairomones during a 12-week study period. Overall, the mean volume of regenerated tissue, as a percentage of the original tail volume, was highest for individuals exposed to the blank versus predator kairomones. When the combined effects of time elapsed since the induction of caudal autotomy and the different treatment regimens were considered, we found that the mean volume of regenerated tissue was significantly greater for control salamanders beginning 8 weeks after autotomy. The mechanism contributing to the differential rates of regeneration among individuals in our treatment groups is unknown, but previous work suggests that elevated stress related to predation threat can have detrimental effects on wound healing and growth in amphibians.

Acute physiological response by the plethodontid salamander Eurycea cirrigera (Southern Two-lined Salamander) to predation stress from alarm chemicals and predator kairomones

“…In the plethodontid salamander E. nana, individuals exhibited an increase in plasma corticosterone after exposure to kairomones from a predatory fish species with a low encounter frequency (Davis and Gabor 2015). Chronic exposure to kairomones from a predatory snake species reduced the rate of tail regeneration in the plethodontid salamander D. ochrophaeus (Payette and Sullivan 2019). Exogenous application of corticosterone produced a 12% increase in oxygen consumption rate for individuals of Plethodon shermani Stejneger, 1906 (Redlegged Salamander) (Wack et al 2012).…”