Techniques for Estimating the Age and Growth of Molluscs: Gastropoda

Gastropoda is a large and diverse group of the Mollusca found almost ubiquitously throughout freshwater, terrestrial, and marine habitats. Marine gastropods often support large commercially important fisheries, many of which are facing concerns over sustainability as landings have increased and populations have dwindled over recent decades. For effective fishery management, the inclusion of an age estimation technique is vital to understand growth rates and population structures to feed into analytical stock assessments. Unlike many bivalve species, gastropods are often difficult to age, especially those which exhibit planispiral coiling of their shells, as no single growth axis can be easily uncovered via sectioning. This review covers a range of techniques that can be used to estimate age and growth rates for many marine gastropod species. Although there is no universal aging technique to cover all species, individual techniques have varying success levels for different species groups.