Assessing the in situ fertilization status of two marine copepod species, Temora longicornis and Eurytemora herdmani; how common are unfertilized eggs in nature?

We utilized an egg staining technique to measure the in situ fertilization success of two marine copepod species, Temora longicornis and Eurytemora herdmani from May to October 2008 in coastal Maine and correlated fertilization success with environmental conditions in their habitat. T. longicornis is a free spawning species that releases eggs into the ambient seawater after mating. In contrast, E. herdmani carries eggs in an egg sac until they hatch. The proportion of fertilized eggs within E. herdmani egg sacs was significantly higher than the freely spawned clutches of T. longicornis. This may be a result of the asymmetrical costs associated with carrying vs. spawning unfertilized eggs. T. longicornis frequently laid both fertilized and unfertilized eggs within their clutch. T. longicornis fertilization was negatively associated with chlorophyll concentration and positively associated with population density in their local habitat. The fertilization status of E. herdmani egg sacs was ...

本研究采用卵子染色技术，于2008年5月至10月间在缅因州沿海海域，对两种海洋桡足类（marine copepod）——长角哲水蚤（Temora longicornis）与赫氏真哲水蚤（Eurytemora herdmani）的原位受精成功率进行了测定，并将受精成功率与其栖息环境的环境条件开展了相关性分析。长角哲水蚤为自由产卵型物种，交配后会将卵子释放至周围海水中；与之相反，赫氏真哲水蚤会将卵携带于卵囊中直至幼体孵化。赫氏真哲水蚤卵囊中受精卵的占比，显著高于长角哲水蚤自由产卵的卵团。该现象可能源于携带未受精卵与释放未受精卵所对应的代价不对称。长角哲水蚤的卵团中常会同时包含受精卵与未受精卵。长角哲水蚤的受精成功率与其栖息环境中的叶绿素浓度呈负相关，而与当地种群密度呈正相关。赫氏真哲水蚤卵囊的受精状态则为……