Butterflies can use ultraviolet markings to find healthier mates .

蝴蝶可以利用紫外线标记找到更加健康的配偶。

Such sites are often used to find and attract potential mates .

这类网站常常被用于找寻和吸引可能的配偶。

Two malenorthern elephant sealsfighting fiercely for mates .

图为两只北方象海豹因为争夺配偶而猛烈的打斗。

Irregular stripes would let potential mates know that someone was not up to snuff .

不规则的条纹会让潜在的配偶知道有人没有达到标准。

Male crickets who guarded their mates against predators gained mating opportunities and offspring .

雄性蟋蟀保护其配偶不受掠食者的害赢，从而赢得交配的机会和繁衍子孙。