A Skeletochronological Study to Determine the Age of the Ringed Salamander (Ambystoma Annulatum)
type: CreativeWork
description: In the fall of 1993 and 1994 in Stone County, Missouri, 202 sexually mature ringed salamanders (Ambystoma Annulatum) were caught in a semi-permanent pond by using pit-fall traps and drift fence. The sex ratio strongly deviated from a 1:1 ration and approached 3:1 in favor of males. The average snout-vent lengths were significantly higher (p<0.0001) in females (91.58mm, Std=7.16mm) than in males (83.66mm, Std=7.33mm). Age was determined by taking cross-sections of phalanges and counting the number of resting lines present. The average number of resting lines present was 9.12 (Std=2.02) in females and 6.65 (Std=1.88) in males. The data suggest that the approximate age of sexual maturity is five to six years (SVL>70mm) in females and three to four years (SVL>61mm) in males. The oldest individual was 15 years. Regression analysis showed a general relationship between SVL size and age for both males (p<0.0001) and females (p<0.0001). Due to large variation in size at a given age, a precise estimation of age is not possible for an individual when only size is known. (male: r²=0.427 ; female: r²=0.304).
abstract: In the fall of 1993 and 1994 in Stone County, Missouri, 202 sexually mature ringed salamanders (Ambystoma Annulatum) were caught in a semi-permanent pond by using pit-fall traps and drift fence. The sex ratio strongly deviated from a 1:1 ration and approached 3:1 in favor of males. The average snout-vent lengths were significantly higher (p<0.0001) in females (91.58mm, Std=7.16mm) than in males (83.66mm, Std=7.33mm). Age was determined by taking cross-sections of phalanges and counting the number of resting lines present. The average number of resting lines present was 9.12 (Std=2.02) in females and 6.65 (Std=1.88) in males. The data suggest that the approximate age of sexual maturity is five to six years (SVL>70mm) in females and three to four years (SVL>61mm) in males. The oldest individual was 15 years. Regression analysis showed a general relationship between SVL size and age for both males (p<0.0001) and females (p<0.0001). Due to large variation in size at a given age, a precise estimation of age is not possible for an individual when only size is known. (male: r²=0.427 ; female: r²=0.304).
author: Winter, David Taylor
keywords: Biology
date published: 1995-05-01T07:00:00Z
date modified: 2026-07-24T03:15:12Z
provider: Missouri State University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Missouri State University