Quinche Laura L, Santana Sharlene E, Rico-Guevara Alejandro
Departamento de Biología, Universidad Nacional de Colombia, Bogotá, Colombia.
Department of Biology, University of Washington, Seattle, Washington, USA.
Anat Rec (Hoboken). 2023 Nov;306(11):2830-2841. doi: 10.1002/ar.25147. Epub 2022 Dec 27.
Dedicated nectarivory is a derived feeding habit that requires specialized cranial and soft-tissue morphologies to extract nectar from flowers. Nectarivory has evolved many times in terrestrial vertebrates, and in four bat families (Pteropodidae, Phyllostomidae, Vespertilionidae, and Mystacinidae). Within phyllostomids, specializations to nectarivory have been well documented in two subfamilies, Glossophaginae and Lonchophyllinae. However, nectarivory has also evolved independently in the genus Phyllostomus (subfamily Phyllostominae). Since Phyllostomus species have an omnivorous diet with a high consumption of nectar, they can be used to explore the basic morphological modifications linked to evolving a nectarivorous habit. Here, we focused on describing and comparing the morphological features potentially associated with nectarivory in Phyllostomus discolor. We present the first detailed tongue and palate morphological descriptions for P. discolor and perform skull morphometric analysis including 10 species. We found hair-like papillae on the tongue of P. discolor, a convergent feature with Glossophaginae and nectarivorous Pteropodids; these papillae likely confer an advantage when feeding on nectar. P. discolor does not show skull morphological features characteristic of nectarivorous bats, such as a long and narrow snout. We pose that the consumption of a variety of food, such as hard insects and fruits, and the large size of P. discolor relative to specialized nectarivores may create trade-offs against morphological specialization of the skull towards nectarivory. In contrast, a long and mobile tongue with hair-like papillae may be an evolutionary solution for nectar extraction that does not have a major impact on this species' ability to feed on other resources.
专门的花蜜摄食是一种衍生的摄食习性，需要特殊的颅骨和软组织形态来从花朵中获取花蜜。花蜜摄食在陆生脊椎动物中已经多次进化，在四个蝙蝠科（狐蝠科、叶口蝠科、蝙蝠科和短尾蝠科）中都有出现。在叶口蝠科中，花蜜摄食的特化在两个亚科——长舌叶口蝠亚科和长鼻叶口蝠亚科中已有充分记录。然而，花蜜摄食在叶口蝠属（叶口蝠亚科）中也独立进化了。由于叶口蝠属物种的饮食杂食，花蜜摄入量高，它们可用于探索与花蜜摄食习性进化相关的基本形态变化。在这里，我们专注于描述和比较变色叶口蝠中可能与花蜜摄食相关的形态特征。我们首次对变色叶口蝠的舌头和腭进行了详细的形态描述，并对包括10个物种的头骨进行了形态测量分析。我们在变色叶口蝠的舌头上发现了毛发状乳头，这是与长舌叶口蝠亚科和食花蜜的狐蝠科的趋同特征；这些乳头在吸食花蜜时可能具有优势。变色叶口蝠没有表现出食花蜜蝙蝠特有的头骨形态特征，比如长而窄的口鼻部。我们认为，食用各种食物，如硬昆虫和水果，以及变色叶口蝠相对于专门的食花蜜蝙蝠体型较大，可能会在头骨向花蜜摄食的形态特化方面产生权衡。相比之下，一条长且可活动的带有毛发状乳头的舌头可能是一种进化解决方案，既能用于获取花蜜，又不会对该物种食用其他资源的能力产生重大影响。
