Tooth sizes as a proxy for estimating body lengths in the porbeagle shark, Lamna nasus

Abstract

　The porbeagle shark, Lamna nasus (Bonnaterre), is an extant lamniform shark. We used linear regression analysis to quantitatively examine the relationships between the total body length (TL) and height of the tooth crown (CH) of each tooth in 19 Lamna nasus individuals ranging 104-244 cm TL from northern Atlantic Ocean. We obtained a total of 25 independent regression equations, and they all suggest that increase in CH of each tooth through tooth replacements is proportional to increase in TL with a high correlation coefficient between TL and CH. Our regression equations can increase the efficiency of the TL data collection from captured individuals useful for ecological monitoring. They can also be used to extrapolate the TL of fossil L. nasus from teeth that would help paleoecological inferences.