Chronological ages of the coelacanths Latimeria chalumnae and Axelrodichthys araripensis by comparing ages from scales and bones


Meeting Abstract

P1-209  Saturday, Jan. 4  Chronological ages of the coelacanths Latimeria chalumnae and Axelrodichthys araripensis by comparing ages from scales and bones NEWBREY, MG*; WOOLFOLK, FR; MARTíN-ABAD, H; MAISEY, JG; Department of Biology, Columbus State University, Columbus, GA; Department of Biology, Columbus State University, Columbus, GA; Universidad Autónoma de Madrid, Madrid, Spain; Paleontology Department, American Museum of Natural History, New York, NY newbrey_michael@columbusstate.edu

Coelacanth age and growth has been argued for the last 22 years and there are only two published papers on their age and growth. Previously published literature suggests longevities of 20 years old or 40 years old based on ages from scales; an examination of their data suggests very irregular growth. A more recent hypothesis suggests a 100-year lifespan from a 21-year in situ study where larger individuals had little to no observable growth. Previous studies also suggest 3 years gestation period based on examination of embryos found in a Latimeria chalumnae female. The largest known individuals of L. chalumnae grow to 1.8 m TL. Our objective is to determine the number of years it takes to attain maximum size. Previous studies have failed to describe growth cessation marks adequately and there were no other structures to compare assigned ages. We used new criteria to identify growth cessation marks on scales of extant (Latimeria chalumnae) and extinct (Axelrodichthys araripensis) individuals. New age assignments for L. chalumnae resulted in higher individual ages than previously noted in the literature. We also compared chronological ages of scales and bones in A. araripensis and found that they agree. Our age assignments suggest a lifespan that exceeds 40 years, and we do not refute the 100 year lifespan hypothesis. The results suggest that coelacanths grow much more slowly than previously reported. This study provides new numerical data that supports the idea of low metabolic rate and slow growth in coelacanths.

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