Even though Glycymeris longior is a clam widely distributed in the SW Atlantic Ocean, little is known about its biology and life history. The present study assessed the periodicity of the internal growth increments of G. longior using thin shell sections. Each internal growth increment was composed of two alternating bands: a translucent band (light-coloured when viewed with transmitted light) and an opaque band (dark-coloured). Annual formation for each pair of bands was demonstrated. The formation of the annual growth increments was synchronous among individuals. Growth was determined from live clams collected at El Sótano, Argentine Sea (age range = 29 to 69 years). According to the growth model, G. longior grows fast during the first 5 years of life and then growth becomes slower in later years; individuals reached 50% and 90% of maximum size at 5 and 13 years of age, respectively. High variability was found in shell height for the first 10 years: differences up to 5–7 mm among individuals were registered for the first 2 years of age, and up to 11 mm between the ages of 3 and 9 years. The growth performance index phi-prime (φ′) and the index of growth performance (P) of G. longior were compared with those of other Glycymeris species. Our results indicate that G. longior is a slow-growing species with a long lifespan (maximum longevity = 69 years).

中文翻译：

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在其分布的南部边缘（阿根廷海），Glycymeris longior（Sowerby，1832）蛤的年龄和生长。

尽管长剑兰（Glycymeris longior）是一种蛤，广泛分布于西南大西洋，但对其生物学和生活史知之甚少。本研究评估了使用薄壳切片对长G.内部生长增量的周期性。每个内部增长增量由两个交替的带组成：半透明带（在透射光下观察时为浅色）和不透明带（深色）。证明了每对乐队的年度形成。个人之间年增长增量的形成是同步的。根据从阿根廷海的埃尔索塔诺（ElSótano）采集的活蛤（年龄范围为29至69岁）确定生长情况。根据生长模型，长寿种在生命的前5年增长很快，而在以后的几年里增长变慢。在5岁和13岁时，个体分别达到最大尺寸的50％和90％。在前10年的壳高中发现高度可变性：前2年的个体之间最大差异为5–7 mm，3至9岁的最大差异为11 mm。与其他甘草种的生长性能指数phi-prime（φ'）和生长性能指数（P）进行了比较。我们的结果表明，G。longior是一种生长缓慢的物种，寿命长（最长寿命= 69年）。与其他甘草种的生长性能指数phi-prime（φ'）和生长性能指数（P）进行了比较。我们的结果表明，G。longior是一种生长缓慢的物种，寿命长（最长寿命= 69年）。与其他甘草种的生长性能指数phi-prime（φ'）和生长性能指数（P）进行了比较。我们的结果表明，G。longior是一种生长缓慢的物种，寿命长（最长寿命= 69年）。