Reproductive Behavior of Polyphemus Limulus

每年春天，大量的马蹄蟹都会迁移到海滩上 沿着大西洋海岸。 雌性和雄性一起埋在 在沙子里产卵，雄性在外面受精。 单身的雄性聚集在筑巢的配偶周围 表明它们也能使卵子受精。 拟议的实地研究 会描述这种不寻常的繁殖行为 物种 子女的父亲是有配偶的， 将使用DNA指纹鉴定来确定单身男性。 描述性观察，标记人群的测量， 实验操作将量化筑巢和交配 行为和人群之间的差异。鲎是独一无二的。 剑尾鱼是唯一现存的 外部受精和水生、自由游动的模式 精子 对它们繁殖的研究将为我们了解 现代节肢动物的祖先 此外，虽然Limulus是 作为地球上研究最多的物种之一， 关于他们的繁殖。 这项实地研究将提供一个 有价值的背景，并将利用，研究 生物学的其他方面。 最后，由于他们的 同步半月繁殖和体外受精 鲎交配与爆发性交配 繁殖两栖动物 因此，对鲎的研究可以提供 对交配进化理论的独立检验 系统.

Every spring large numbers of horseshoe crabs migrate to beaches along the Atlantic coast. Females, with males attached, bury in the sand, laying eggs which the male fertilizes externally. Unattached males aggregate around nesting pairs and evidence suggests that they also fertilize eggs. The proposed field study will characterize the unusual reproductive behavior of this species. The proportion of offspring fathered by attached and unattached males will be determined using DNA fingerprinting. Descriptive observations, measurements of marked populations and experimental manipulations will quantify nesting and mating behavior, and differences between populations. Limulus is unique. The Xiphosurida are the only extant arthropods with the primitive pattern of external fertilization and aquatic, free-swimming sperm. A study of their breeding will provide insight into the ancestors of modern arthropods. Furthermore, although Limulus is one of the best-studied species on the planet, little is known about their reproduction. This field study will provide a valuable context for, and will take advantage of, research on other aspects of their biology. Finally, because of their synchronized, semi-lunar breeding and external fertilization, Limulus mating shows profound similarities to explosively breeding amphibians. Therefore, the study of Limulus may provide an independent test of theories on the evolution of mating systems.