Sequential hermaphroditism (sex change) is understood to be a strategy that maximizes lifetime reproduction in systems where one sex confers highest fitness early in life, and the other later in life. This strategy is evolutionarily stable despite costs to growth, survival, or current reproduction. Few studies have examined advantages of sex change outside of reproduction. The mangrove rivulus fish, Kryptolebias marmoratus, presents a unique system in which to study non-reproductive consequences of sex change because reproductive opportunity decreases significantly with sex change. In natural conditions, individuals develop as self-fertilizing simultaneous hermaphrodites. Some individuals change sex to male at various points after sexual maturity, even in isolation, essentially foregoing future reproductive assurance. In a large-scale experiment that examined fitness differences among individuals exposed to ecologically relevant environmental challenges, we found that individuals that change sex from hermaphrodite to male had overwhelmingly greater chances of survival compared to those that remained hermaphrodite. Furthermore, hermaphrodites derived from lineages with higher propensities to change sex experienced greater survival advantages by changing sex. Our results indicate that sex change may be a survival strategy, one with genotype-dependent consequences.

中文翻译：

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性别改变作为一种生存策略

顺序雌雄同体（性别变化）被理解为一种策略，在系统中最大化终生繁殖，其中一个性别在生命早期赋予最高适应性，另一个在生命后期赋予最高适应性。尽管有增长、生存或当前繁殖的成本，但这种策略在进化上是稳定的。很少有研究考察过性变化在生殖之外的优势。红树林河鱼 Kryptolebias marmoratus 提供了一个独特的系统来研究性别变化的非生殖后果，因为生殖机会随着性别变化而显着减少。在自然条件下，个体发育为同时自我受精的雌雄同体。有些人在性成熟后的不同时间点将性别变为男性，即使是孤立的，基本上放弃了未来的生殖保证。在一项检查暴露于生态相关环境挑战的个体之间的健康差异的大规模实验中，我们发现，与保持雌雄同体的个体相比，将性别从雌雄同体变为雄性的个体的生存机会要大得多。此外，来自具有较高改变性别倾向的谱系的雌雄同体通过改变性别获得了更大的生存优势。我们的结果表明，性别变化可能是一种生存策略，具有基因型依赖的后果。来自具有较高改变性别倾向的谱系的雌雄同体通过改变性别获得了更大的生存优势。我们的结果表明，性别变化可能是一种生存策略，具有基因型依赖的后果。来自具有较高改变性别倾向的谱系的雌雄同体通过改变性别获得了更大的生存优势。我们的结果表明，性别变化可能是一种生存策略，具有依赖于基因型的后果。