Worldwide, macroalgae have invaded near‐shore marine ecosystems. However, their haplodiplontic life cycles have complicated efforts to predict patterns of growth and spread, particularly since most theoretical predictions are derived from diplontic taxa (i.e., animals). To complete one revolution of the life cycle, two separate ploidy stages, often including separate haploid sexes, must pass through development and reproduction. In the case of the invasive, red macroalga Agarophyton vermiculophyllum, during the invasion of soft‐sediment estuaries throughout the Northern Hemisphere, diploid tetrasporophytes came to dominate all free‐floating populations and haploid gametophytes were consistently lost. The ecological hypothesis of nutrient limitation might contribute to an explanation of this pattern of tetrasporophytic dominance in free‐floating populations. Under this hypothesis, gametophytes should outperform tetrasporophytes under nutrient limited conditions, but tetrasporophytes should be better able to exploit optimal or even abundant nutrient conditions, such as in eutrophic estuaries. We sampled tetrasporophytes, male gametophytes, and female gametophytes from two sites each located on either side of the Delmarva Peninsula that separates the Chesapeake Bay from the Atlantic Ocean. We subjected apices excised from multiple thalli from each life cycle stage to a nutrient‐enriched and a nutrient‐poor seawater treatment and assessed growth and survival. While nutrient addition increased growth rates, there was no significant difference among ploidies or sexes. Gametophytes did, however, suffer higher mortality than tetrasporophytes. We discuss how nutrient‐dependent differences in growth and survival may contribute to observed patterns of tetrasporophytic dominance in soft‐sediment A. vermiculophyllum populations.

中文翻译：

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营养物质对侵袭性单倍体红色大藻的倍性特异性性能的影响。

在世界范围内，大型藻类已经入侵了近海海洋生态系统。然而，它们的单倍体生命周期为预测生长和扩散模式付出了艰巨的努力，特别是因为大多数理论上的预测都来自二倍体类群（即动物）。为了完成生命周期的一场革命，必须经历发育和繁殖的两个不同的倍性阶段，通常包括不同的单倍体性别。如果是侵入性的红色大型藻类Agarophyton vermiculophyllum在整个北半球的软沉积河口入侵期间，二倍体四孢子植物逐渐占据了所有自由流动种群的位置，并且单倍体配子体不断丢失。养分限制的生态学假设可能有助于解释自由流动人口中这种四孢子体优势的模式。在这种假设下，配子体在营养有限的条件下应胜过四孢子体，但四孢子体应能够更好地利用最佳甚至丰富的营养条件，例如在富营养化河口。我们从分别位于切萨皮克湾和大西洋之间的德尔马瓦半岛两侧的两个地点采样了四孢子体，雄配子体和雌配子体。我们在每个生命周期的各个阶段从多个海藻中切除的顶点进行了营养丰富和营养贫乏的海水处理，并评估了其生长和存活率。营养添加增加了生长速度，但在倍性或性别之间没有显着差异。然而，配子体确实比四孢子体遭受更高的死亡率。我们讨论了营养和营养依赖的生长和生存差异如何促进软沉积中四孢子体优势的观察模式A. mic叶种群。