Abstract

The individual linear growth of 90 specimens of the freshwater pearl mussel Margaritifera margaritifera was studied by measuring the successive annual rings on the surface of the shell. It was found that the growth of each mollusk can be described using a united equation, a particular case of which is the Bertalanffy equation with an average growth retardation coefficient a = 0.048 year^–1 and the coefficient of the initial conditions d = 5.3 mm/year. It was noted that the growth of mollusks is accompanied by three regular biorhythms with periods of 13.4, 6.8, and 4.0 years, with the first two biorhythms fading, the latter having a constant amplitude. It was found that a decrease in the amplitude of fading biorhythms can be described by a power equation with the same coefficients. Questions related to the nature of the biorhythms identified are discussed.

中文翻译：

---

瓦尔祖加河人口（摩尔曼斯克州）的欧洲贻贝贻贝玛格丽塔玛（Bivalvia，Margaritiferidae）的生长节律

摘要

通过测量壳表面连续的年轮，研究了90个淡水珍珠贻贝玛格丽塔玛格丽塔玛的个体线性增长。发现可以用一个联合方程来描述每种软体动物的生长，其中一个特例是Bertalanffy方程，其平均生长延迟系数a = 0.048 year ^–1和初始条件系数d= 5.3毫米/年。值得注意的是，软体动物的生长伴随着三个规则的生物节律，分别为13.4、6.8和4.0年，前两个生物节律逐渐消失，后者的振幅恒定。已经发现，可以用具有相同系数的幂方程来描述衰落生物节律幅度的减小。讨论与所确定的生物节律的性质有关的问题。