In promiscuous species, multiple sites of sperm storage are considered to be an adaptation of females for post-copulatory control over sperm storage and selection to control offspring paternity. 1,2 In the stylommatophoran gastropod Arianta arbustorum (Linnaeus), the sperm-storing spermatheca consists of two to nine blind tubules: a main tubule and one to eight lateral tubules. 3,4 The considerable variability in paternity patterns of double-mated individuals and the observation that incoming sperm are not equally distributed among spermathecal tubules, i.e. some are filled and others remain empty, suggest that A. arbustorum may store and use sperm from different mating partners selectively. 3,5 In addition, ultrastructural analyses of the spermathecal epithelium with its ciliation and of the musculature surrounding the spermatheca indicate that anatomical correlates necessary for sperm manipulation exist. 6,7 The sperm storage sites themselves may be subject to sexual selection, provided that there is heritable variability of those structures, which are important for exercising cryptic female choice. 8,9 In a previous study, we investigated whether different risks of sperm competition, which we expected in populations with different densities, would affect spermathecal morphology. There may be several reasons why we did not detect any density dependence including lack of heritability. 4,10 Instead, the number of spermathecal tubules might depend on an individual’s age or state of sexual maturity. The ontogeny of a complex spermatheca such as that of A. arbustorum has not been investigated in much detail so far. It has only been observed 11 that in A. arbustorum the fertilization pouch (sensu 3 ), of which the spermatheca is one part, develops at an age of about 6 weeks. However, the development of the structures of the fertilization pouch including the spermatheca was not studied so far. In the present paper we investigate the development of the spermatheca in A. arbustorum. We were particularly interested in whether the number of spermathecal tubules increases with age/size (see below) or whether the anlage of all spermathecal tubules is formed during an early stage of ontogenesis. The latter would be an indication that the complexity of the spermatheca is mainly genetically controlled and, thus, heritable. A. arbustorum is common throughout Europe from the Pyrenees to the Ukraine reaching northwards as far as Scandinavia. The species occurs from the lowland up to 3000 m a.s.l. 12,13 The snail has determinate growth indicated by a reflected and thickened lip. Formation of the lip and sexual maturity roughly coincide at an age of 2‐4 years, and adults live another 3‐4 years. 14 A. arbustorum mates repeatedly during the

中文翻译：

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Arianta arbustorum (Stylommatophora: Helicidae) 精子储存器官的发育

在混杂物种中，精子储存的多个部位被认为是雌性对精子储存的交配后控制和选择以控制后代亲子关系的一种适应。1,2 在 stylommatophoran 腹足动物 Arianta arbustorum (Linnaeus) 中，储存精子的受精囊由 2 到 9 个盲小管组成：一个主小管和 1 到 8 个侧小管。3,4 双重交配个体的父系模式存在相当大的变异性，并且观察到进入的精子在受精囊小管中分布不均，即有些被填满，而另一些则保持空洞，这表明 A. arbustorum 可能储存和使用来自不同交配的精子有选择的合作伙伴。3,5 此外，对受精囊上皮及其纤毛和受精囊周围肌肉组织的超微结构分析表明存在精子操作所需的解剖学关联。6,7 精子储存点本身可能会受到性选择的影响，前提是这些结构具有可遗传的变异性，这对于行使神秘的女性选择很重要。8,9 在之前的一项研究中，我们调查了不同密度人群中精子竞争的不同风险是否会影响精囊形态。我们没有检测到任何密度依赖性可能有几个原因，包括缺乏遗传力。4,10 相反，精囊小管的数量可能取决于个人的年龄或性成熟状态。迄今为止，尚未对复杂的受精囊（例如 A. arbustorum 的受精囊）的个体发育进行详细研究。仅观察到 11 在 A. arbustorum 中，受精囊（sensu 3 ）在大约 6 周龄时发育，受精囊是其中的一部分。然而，到目前为止还没有研究包括受精囊在内的受精袋结构的发展。在本文中，我们调查了 A. arbustorum 中的受精囊的发育。我们特别感兴趣的是，受精囊小管的数量是否随着年龄/大小而增加（见下文），或者所有受精囊小管的原基是否在个体发育的早期阶段形成。后者表明受精囊的复杂性主要受基因控制，因此是可遗传的。一种。arbustorum 在整个欧洲很常见，从比利牛斯山脉到乌克兰，向北延伸到斯堪的纳维亚半岛。该物种出现在海拔 3000 米以下的低地 12,13 蜗牛具有通过反射和加厚的唇部确定的生长。唇的形成和性成熟大致在 2-4 岁时重合，成人又活了 3-4 年。14 A. arbustorum 在繁殖期间反复交配