A review of research on life‐cycle events in field and laboratory populations of monogonont rotifers shows that there is great variation at multiple levels: (1) degree of sexual dimorphism; (2) occurrence and timing of sex; (3) propensity for sex during sexual periods; (4) factors controlling initiation of sex; and (5) timing and extent of emergence from diapause. There is no regular pattern where: (1) fertilised resting eggs hatch to start the growing season; (2) populations develop via female parthenogenesis during favourable conditions; and then (3) bisexual reproduction with resting‐egg production occurs during later, unfavourable conditions. Sexual reproduction in natural populations can occur throughout much of the growing season, be restricted to some period(s) during the growing season, or be completely absent. During sexual reproduction in both natural and laboratory populations, only some fraction of females produces males or resting eggs. This bet‐hedging strategy can prevent a population crash and permits future population growth via female parthenogenesis. Selection against sexual reproduction, and rapid loss of sex, can occur. Laboratory experiments with pond‐dwelling species have identified specific environmental factors that induce sex in different species: (1) increasing population density; (2) dietary tocopherol (vitamin E) and (3) long photoperiods. These factors generally are associated with favourable conditions for population growth and production of energy‐rich resting eggs: (1) large population size; (2) high probability of contacts between males and fertilisable females; and (3) nutritious diets. Endogenous factors can inhibit responses to these environmental inducers, and thus favour female parthenogenesis. The timing of resting‐egg hatching depends on: (1) occurrence of specific environmental conditions; (2) the minimum duration of obligate diapause; and (3) the genotype and physiology of females producing resting eggs. Hatching may occur shortly after oviposition, after a long diapause before or at the start of a new growing season, or throughout the growing season. Hatching can be massive and contribute substantially to population growth and genetic diversity. Areas for future research include: (1) determining the timing and extent of sex and resting‐egg hatching in more natural populations, especially those that are marine, benthic, sessile, and interstitial; and (2) identifying environmental and physiological factors controlling these events.

中文翻译：

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单角轮虫生命周期的变化：对性的承诺和从滞育中的出现

对单角轮虫野外和实验室种群生命周期事件研究的回顾表明，在多个水平上存在很大的变异：（1）性二态性的程度；(2) 性行为的发生和时间；(3) 性生活期间的性倾向；(4) 控制性行为开始的因素；(5) 滞育出现的时间和程度。没有以下规律：（1）受精休眠卵孵化开始生长季节；(2) 种群在有利条件下通过雌性孤雌生殖发育；然后 (3) 在较晚的不利条件下，会发生带有静息卵的双性生殖。自然种群中的有性繁殖可以在整个生长季节的大部分时间发生，也可以仅限于生长季节的某些时期，或者完全不存在。在自然种群和实验室种群的有性繁殖过程中，只有一部分雌性产生雄性或休眠卵。这种赌注对冲策略可以防止人口崩溃，并通过女性孤雌生殖允许未来的人口增长。可能会发生针对有性生殖的选择和快速的性丧失。池塘栖息物种的实验室实验已经确定了导致不同物种发生性别的特定环境因素：（1）增加种群密度；(2) 膳食生育酚 (维生素 E) 和 (3) 长光周期。这些因素通常与人口增长和富含能量的静息蛋生产的有利条件有关：（1）人口规模大；(2) 雄性与可生育雌性接触的概率高；(3) 营养丰富的饮食。内源性因素可以抑制对这些环境诱导物的反应，从而有利于雌性孤雌生殖。静蛋孵化的时间取决于：（1）特定环境条件的发生；(2) 专性滞育的最短持续时间；(3) 产卵雌性的基因型和生理。孵化可能发生在产卵后不久，在新生长季节之前或开始时的长时间滞育后，或整个生长季节。孵化可以是大规模的，并且对种群增长和遗传多样性做出重大贡献。未来研究的领域包括：(1) 确定更自然种群，尤其是海洋、底栖、无柄和间质种群中的性别和休眠卵孵化的时间和程度；