Cordero A, Carbone Ss, Utzeri C
Departamento de Ecoloxia e Bioloxia Animal, Universidade de Vigo
Anim Behav. 1998 Jan;55(1):185-97. doi: 10.1006/anbe.1997.0603.
Female colour polymorphism is a perplexing characteristic of many damselfly species. In Ischnura elegans three female phenotypes occur, one of which has the same blue coloration as the male (androchromes) whilst the others are inconspicuous brown gynochromes (infuscans and infuscans-obsoleta morphs). By marking a natural population near Rome, Italy, we found that all female phenotypes have similar survivorship, but they differ in mating frequency. Androchromes represented 55% of females but were involved in 43% of matings, whereas infuscans females represented 27% of females and 40% of matings and the infuscans-obsoleta phenotype 18% of females and 17% of matings. Old androchromes stored significantly less sperm in their spermatheca than old gynochromes, suggesting that they had mated less often. The majority of mature androchromes were observed alone (54%) when the majority of gynochromes (82-84%) were mating. When live tethered conspecifics were presented to males, blue models (male and androchrome female) were less attractive than brown models (gynochrome females). In contrast, all female colour morphs and males were equally (highly) attractive to males when the models were dead. Androchromes were significantly larger than gynochromes. Our results indicate that androchrome females mate less often than gynochromes, which could be a means of avoiding unnecessary and costly matings, but some androchrome females failed to reproduce (mate or oviposit) probably because they were unable to mate at all. The different explanations for the maintenance of this polymorphism in I. elegans are discussed. Copyright 1998 The Association for the Study of Animal Behaviour.
雌性体色多态性是许多豆娘物种令人费解的一个特征。在优雅蟌中存在三种雌性表型，其中一种与雄性具有相同的蓝色体色（雄性色型），而其他的是不显眼的棕色雌性色型（暗褐色型和暗褐色 - 淡色型变体）。通过标记意大利罗马附近的一个自然种群，我们发现所有雌性表型具有相似的存活率，但它们在交配频率上存在差异。雄性色型雌性占雌性总数的55%，但参与了43%的交配，而暗褐色型雌性占雌性总数的27%，参与了40%的交配，暗褐色 - 淡色型表型的雌性占雌性总数的18%，参与了17%的交配。年老的雄性色型雌性在受精囊中储存的精子明显少于年老的雌性色型，这表明它们交配的频率较低。观察到大多数成熟的雄性色型雌性单独出现（54%），而大多数雌性色型（82 - 84%）正在交配。当向雄性展示活的同种个体时，蓝色模型（雄性和雄性色型雌性）比棕色模型（雌性色型雌性）吸引力小。相反，当模型是死的时，所有雌性色型和雄性对雄性的吸引力是相同的（都很高）。雄性色型明显比雌性色型大。我们的结果表明，雄性色型雌性的交配频率低于雌性色型，这可能是一种避免不必要且代价高昂的交配的方式，但一些雄性色型雌性未能繁殖（交配或产卵），可能是因为它们根本无法交配。文中讨论了关于优雅蟌中这种多态性维持的不同解释。版权所有1998动物行为研究协会。
