Functional morphology of sexually selected gentalia in the water strider Aquarius remigis
Functional morphology of sexually selected gentalia in the water strider Aquarius remigis
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DOI：
10.1139/z03-021
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发表时间：
2003-03-01
影响因子：
1.4
通讯作者：
Zahiri, N
中科院分区：
文献类型：
--
作者：
Fairbairn, DJ;Vermette, R;Zahiri, N
在Aquarius remigis（Say）中，性选择倾向于生殖器较长的雄性。我们使用视频分析加上光学和扫描电子显微镜来检查生殖器的结构，运动和关节，作为确定这种选择的功能基础的第一步。雄性A.生殖器的特征是长而结实的生殖器节;在前生殖器节的后缘有一个明显的腹侧正中切迹;一个膨大的阴茎，顶端有一个独特的延长的硬化板;以及一个大的、被刺覆盖的膜状叶，在雌性生殖道内膨胀。在交配前和交配期间对生殖器相互作用的详细检查使我们能够推断出这些区别特征的功能意义。我们假设，通过增加阴茎的长度，流动性，强度和刚度，前三个特征增加男性的能力，以实现插入，尽管积极的女性阻力，并保持插入在这个物种的特点，在长期的交配。大的棘叶的膨胀可能有助于后者的功能，也可能通过取代或破坏以前男性的精子直接影响受精成功。我们讨论这些解释的背景下，生殖器的共同进化和性冲突的Gerridae目前的理论。
In the water strider Aquarius remigis (Say), sexual selection favours males with longer genitalia. We used video analysis plus light and scanning electron microscopy to examine the structure, movement, and articulation of the genitalia as a first step in determining the functional basis of this selection. Male A. remigis are characterized by long, robust genital segments; a marked ventral median notch in the posterior margin of the pregenital segment; an enlarged phallus tipped with a uniquely prolonged sclerotized plate; and a large, spine-covered, membranous lobe that inflates within the female's reproductive tract. Detailed examinations of genital interactions prior to and during copulation allow us to deduce the functional significance of these distinguishing traits. We postulate that by increasing the length, mobility, strength, and rigidity of the phallus, the first three traits increase the ability of males to achieve intromission in spite of active female resistance, and to maintain intromission during the prolonged copulations characteristic of this species. Inflation of the large, spinous lobe probably contributes to the latter function, and may also directly affect fertilization success by displacing or damaging sperm from previous males. We discuss these interpretations in the context of current theories of genitalic coevolution and sexual conflict in the Gerridae.