{"id":{"repo_id":"mo-state","oai_identifier":"oai:bearworks.missouristate.edu:theses-1208"},"canonical_url":"https://search.dev.ndltd.org/etd/mo-state/oai:bearworks.missouristate.edu:theses-1208","repository":{"repo_id":"mo-state","name":"Missouri State University","base_url":"https://bearworks.missouristate.edu/do/oai/"},"display":{"title":"A Skeletochronological Study to Determine the Age of the Ringed Salamander (Ambystoma Annulatum)","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).","abstract_html":"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&lt;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&gt;70mm) in females and three to four years (SVL&gt;61mm) in males. The oldest individual was 15 years. Regression analysis showed a general relationship between SVL size and age for both males (p&lt;0.0001) and females (p&lt;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_has_math":false,"creators":["Winter, David Taylor"],"institution":null,"degree_name":"Master of Science in Biology","degree_level":"Masters","degree_discipline":"Biology","degree_department":null,"school":null,"contributors":["Robert Wilkinson"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1995,"date_issued":"1995-05-01T07:00:00Z","date_published":"1995-05-01T07:00:00Z","updated_at":"2026-07-24T03:15:12Z","subjects":["Biology"],"languages":[],"rights":["© David Taylor Winter"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://bearworks.missouristate.edu/theses/207","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Robert Wilkinson"]},{"key":"dc:creator","label":"Author","values":["Winter, David Taylor"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science in Biology"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biology"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["© David Taylor Winter"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://bearworks.missouristate.edu/theses/207"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["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)."]},{"key":"dc:title","label":"Title","values":["A Skeletochronological Study to Determine the Age of the Ringed Salamander (Ambystoma Annulatum)"]}]}],"canonical_facts":{"dc:contributor":["Robert Wilkinson"],"dc:creator":["Winter, David Taylor"],"dc:description.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)."],"dc:identifier":["https://bearworks.missouristate.edu/theses/207"],"dc:rights":["© David Taylor Winter"],"dc:subject":["Biology"],"dc:title":["A Skeletochronological Study to Determine the Age of the Ringed Salamander (Ambystoma Annulatum)"],"thesis:degree_discipline":["Biology"],"thesis:degree_level":["Masters"],"thesis:degree_name":["Master of Science in Biology"]},"updated_at":"2026-07-24T03:15:12Z"}