Caudal pseudoautotomy in Heller’s Red-necked Keelbacks, Rhabdophis helleri (Schmidt 1925)

Abstract

R eptiles employ numerous antipredator strategies ranging from crypsis to aposematic coloration, from feigning death to biting, and the deliberate loss of the tail in response to an attack by a predator (Greene 1988). Tail loss occurs in defined regions of caudal vertebrae and can be intra-or intervertebral (Ananjeva and Orlov 1994). Further classifications (Arnold 1984;Slowinski and Savage 1995;Savage and Slowinski 1996;Bateman and Fleming 2009) include "autotomy" (intravertebral breakage along a pre-existing fracture plane that passes through a centrum and neural arch, spontaneous separation, and regeneration), intravertebral breakage along a fracture plane without regeneration, "pseudoautotomy" (intervertebral breakage between adjacent caudal vertebrae, non-spontaneous separation, no regeneration), and intervertebral breakage with some regeneration. Intravertebral breakage without regeneration, known to occur in some amphisbaenians, is considered an intermediate con-dition, whereas the intervertebral breakage with regeneration occurs in some agamid lizards (Arnold 1984). Only intervertebral breakage is known in snakes, but it can be either specialized for tail loss (tails are fragile, thickened, and extremely long) or unspecialized (Savage and Crother 1989;Savage and Slowinski 1996). Pseudoautotomy has been reported in species of the genera Scaphiodontophis, Pliocercus, Thamnophis,

Caudal pseudoautotomy in three Sri Lankan species of snakes (Natricidae and Viperidae)

“…Among lizards, this behavior has been observed in 13 of 20 lizard families (Downes and Shine 2001) and its evolutionary history is traceable to Early-Permian captorhinids. By detaching the tail from the body, lizards can escape a predator's grasp while the severed tail continues to spontaneously and vigorously writhe, attracting the predator's attention away from the lizard (Edmunds 1974;Bateman and Fleming 2009).However, caudal pseudoautotomy, intervertebral tail detachment in response to mechanical resistance without tail regeneration, is infrequently observed among snakes (Ananjeva and Orlov 1994;Dutta et al 2022), with this behavior mostly documented among African colubrids (Broadley 1987;Akani et al 2002). Thus far, caudal pseudoautotomy has been recorded in only a few snake genera (Amphiesma, Coluber,…”

“…However, caudal pseudoautotomy, intervertebral tail detachment in response to mechanical resistance without tail regeneration, is infrequently observed among snakes (Ananjeva and Orlov 1994;Dutta et al 2022), with this behavior mostly documented among African colubrids (Broadley 1987;Akani et al 2002). Thus far, caudal pseudoautotomy has been recorded in only a few snake genera (Amphiesma, Coluber,…”