Shark conservation and management is often hindered by a lack of basic biological information for most species. An understanding of the age structure and growth dynamics of a population is important for effective conservation and management because this information is often utilized for determination of natural mortality and longevity. Ultimately age and growth information is used for calculation of vital rates in population models. Over the last few years there have been advances in the quantitative study of age and growth of chondrichthyan fishes. Novel approaches to ageing of various chondrichthyan fishes continue to arise.

This volume is a collection of papers on several of these topics that include new hard parts (e.g. caudal thorns) for assessments of age, new techniques for validation (e.g. bomb radiocarbon) and reexaminations of previous age and growth models. This volume also contains papers on the importance of assessing the precision and accuracy of statistical formulas, analyses, and models that are used in age and growth studies. There is currently a great deal of research being conducted, some of which is truly "pushing the envelope," in attempts to assess the life history parameters of numerous chondrichthyan fishes.

Zusammenfassung

Over the last few years there have been advances in the quantitative study of age and growth of chondrichthyan fishes. Novel approaches to ageing of various chondrichthyan fishes continue to arise.

This volume is a collection of papers on several of these topics that include new hard parts (e.g. caudal thorns) for assessments of age, new techniques for validation (e.g. bomb radiocarbon) and reexaminations of previous age and growth models. This volume also contains papers on the importance of assessing the precision and accuracy of statistical formulas, analyses, and models that are used in age and growth studies. There is currently a great deal of research being conducted, some of which is truly "pushing the envelope," in attempts to assess the life history parameters of numerous chondrichthyan fishes.

Inhalt
Acknowledgment of referees.- Age and growth studies of chondrichthyan fishes: the need for consistency in terminology, verification, validation, and growth function fitting.- Age and growth of the sandbar shark, Carcharhinus plumbeus, in Hawaiian waters through vertebral analysis.- A re-examination of the age and growth of sand tiger sharks, Carcharias taurus, in the western North Atlantic: the importance of ageing protocols and use of multiple back-calculation techniques.- Comparing external and internal dorsal-spine bands to interpret the age and growth of the giant lantern shark, Etmopterus baxteri (Squaliformes: Etmopteridae).- The potential use of caudal thorns as a non-invasive ageing structure in the thorny skate (Amblyraja radiata Donovan, 1808).- Terminology for the ageing of chondrichthyan fish using dorsal-fin spines.- Do differences in life history exist for blacktip sharks, Carcharhinus limbatus, from the United States South Atlantic Bight and Eastern Gulf of Mexico?.- Evidence of two-phase growth in elasmobranchs.- Two Bayesian methods for estimating parameters of the von Bertalanffy growth equation.- A critical appraisal of marginal increment analysis for assessing temporal periodicity in band formation among tropical sharks.- Elemental signatures in the vertebral cartilage of the round stingray, Urobatis halleri, from Seal Beach, California.- Bomb dating and age validation using the spines of spiny dogfish (Squalus acanthias).- Investigations of ?14C, ? 13C, and ? 15N in vertebrae of white shark (Carcharodon carcharias) from the eastern North Pacific Ocean.- Application of bomb radiocarbon chronologies to shortfin mako (Isurus oxyrinchus) age validation.- Validated age and growth estimates for the shortfin mako, Isurus oxyrinchus, in the NorthAtlantic Ocean.- Validated age and growth of the sandbar shark, Carcharhinus plumbeus (Nardo 1827) in the waters off Western Australia.- Analysis of variability in vertebral morphology and growth ring counts in two Carcharhinid sharks.- Morphometric minefieldstowards a measurement standard for chondrichthyan fishes.