History and Mystery of Age and Growth Studies in Elasmobranchs: Common Methods and Room for Improvement

Age determination is a fundamental eld of study that is of critical importance to management and conservation of a species (Cortés, 2002; Harry, 2017). Determining population demographics can only be accomplished with the input of age data; yet, despite years of age determination efforts, it continues to be one of the most challenging and nuanced aspects of life history investigation in elasmobranchs. A variety of methods have been used to determine ages in elasmobranchs, some successful and some not. New techniques to obtain accurate and precise ages are being developed, and it is important to recognize the value of both old and new methodologies.