AUTHOR=Bargione Giada , Vasapollo Claudio , Donato Fortunata , Virgili Massimo , Petetta Andrea , Lucchetti Alessandro 

TITLE=Age and Growth of Striped Venus Clam Chamelea gallina (Linnaeus, 1758) in the Mid-Western Adriatic Sea: A Comparison of Three Laboratory Techniques

JOURNAL=Frontiers in Marine Science

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2020.582703

DOI=10.3389/fmars.2020.582703

ISSN=2296-7745

ABSTRACT=<p>Age and growth studies provide critical data for clam fishery management. Three aging techniques, thin sections and acetate peel replicas – which involve shell sectioning – and surface growth rings were used to estimate the age and growth of <italic>Chamelea gallina</italic> populations in the mid-western Adriatic Sea. Their results were compared to identify the most reliable and least time-consuming approach. There were no significant differences between the two shell sectioning techniques (χ<italic><sup>2</sup></italic> = 4.66, df = 3, <italic>p</italic> = 0.198), which were described by the same von Bertalanffy (VBF) growth curve parameters (<italic>L</italic><sub>8</sub> = 43.9, <italic>k</italic> = 0.26, <italic>t</italic><sub>0</sub> = −0.84), whereas significantly different <italic>L</italic><sub>8</sub> and <italic>k</italic> values were found between the two shell sectioning techniques and surface growth rings (<italic>L</italic><sub>8</sub>: χ<italic><sup>2</sup></italic> = 13.62, df = 1, <italic>p</italic> &lt; 0.001; <italic>k</italic>: χ<italic><sup>2</sup></italic> = 9.18, df = 1, <italic>p</italic> &lt; 0.002; these statistics refer to the comparison between acetate peels and surface growth rings). The latter approach proved unreliable and error-prone, as it underestimated age and overestimated the growth rate (<italic>L</italic><sub>8</sub> = 26.4, <italic>k</italic> = 1.91, <italic>t</italic><sub>0</sub> = −0.11). Although the thin sections and acetate peel techniques both provide reliable age and growth estimates, the former approach was less time-consuming. Our analyses demonstrated that shell growth is slower in the cold season and in older specimens and that it has slowed down over the past few decades.</p>