Data from: Sexual cannibalism increases male material investment in offspring: quantifying terminal reproductive effort in a praying mantis

Models of the evolution of sexual cannibalism argue that males may offset the cost of cannibalism if components of the male body are directly allocated to the eggs that they fertilize. We tested this idea in the praying mantid Tenodera sinensis. Males and females were fed differently radiolabelled crickets and allowed to mate. Half of the pairs progressed to sexual cannibalism and we prevented cannibalism in the other half. We assess the relative allocation of both male-derived somatic materials and ejaculate materials into the eggs and soma of the female. Our results show that male somatic investment contributes to production of offspring. The eggs and reproductive tissues of cannibalistic females contained significantly more male-derived amino acids than those of non-cannibalistic females, and there was an increase in the number of eggs produced subsequent to sexual cannibalism. Sexual cannibalism thus increases male material investment in offspring. We also show that males provide substantial investment via the ejaculate, with males passing about 25% of their radiolabelled amino acids to females via the ejaculate even in the absence of cannibalism.

Usage Notes
Sexual cannibalism and paternal effortMantids were fed radiolabeled amino acids and allowed to mate. Females of one treatment group cannibalized their mate and females of the other treatment group did not. We measured transfer of radioisotope from male to female and into female reproduction.

关于性食同类（sexual cannibalism）的演化模型指出，若雄性躯体组分可直接分配至其所受精的卵粒中，雄性或可抵消性食同类行为带来的生存代价。本研究以中华大刀螳（Tenodera sinensis）为实验对象对该假说进行验证。我们分别用经不同放射性标记的蟋蟀饲喂雌雄螳螂，并使其完成交配。其中半数交配组发生了性食同类行为，我们对另一半交配组则阻止了该行为的发生。我们评估了雄性来源的体细胞物质与射精物质向雌性卵粒及躯体的相对分配情况。
研究结果显示，雄性体细胞投入可对子代产生作出贡献。发生性食同类行为的雌性，其卵粒与生殖组织中含有的雄性来源氨基酸含量显著高于未发生该行为的雌性；且性食同类行为发生后，雌性的产卵量有所提升。由此可见，性食同类行为可增强雄性对子代的物质投入。本研究还证实，雄性可通过射精途径提供大量物质投入：即便未发生性食同类行为，雄性仍可通过射精将约25%的放射性标记氨基酸传递给雌性。

使用说明
性食同类与父本投入
本研究将螳螂饲喂经放射性标记的氨基酸后使其交配。其中一组处理组的雌性会捕食其配偶，另一组处理组的雌性则不会发生此类行为。我们检测了放射性同位素从雄性向雌性，以及向雌性生殖系统的转移情况。