Analysis of bomb radiocarbon data for common thresher sharks, Alopias vulpinus, in the northwestern Atlantic Ocean with revised growth curves

TitleAnalysis of bomb radiocarbon data for common thresher sharks, Alopias vulpinus, in the northwestern Atlantic Ocean with revised growth curves
Publication TypeJournal Article
Year of Publication2015
AuthorsNatanson, LJ, Hamady, LLing, Gervelis, BJ
JournalENVIRONMENTAL BIOLOGY OF FISHES
Volume99
Pagination39-47
Date PublishedDEC
Type of ArticleArticle
ISSN0378-1909
KeywordsAge, Carbon-14, Centra, Elasmobranchs, Vertebral column
Abstract

Bomb radiocarbon dating was used to determine the periodicity of band pair formation in the vertebral centra of three common thresher sharks (Alopias vulpinus). The traditional interpretation of band pairs were accurate (i.e. annual) up to approximately 14 years of age. In older individuals, band pair counts underestimated age. A new maximum validated age was estimated to be 38 years (an increase of 18 years over the band count estimates). Previously reported length at age estimates for common thresher sharks up to 14 years were used in conjunction with the two older validated estimates to develop a revised growth curve for the species, which was described using the Schnute general model (sexes combined). Updated estimates of age at maturity remained the same for males (8 years) and increased by one year to 13 years for females. The primary finding was the increase in longevity for this species from a band pair count estimate of 24 years to a bomb radiocarbon validated estimate of 38 years, indicating this species lives much longer than previously thought.

DOI10.1007/s10641-015-0452-y