Morphological study of the lingual papillae in the fruit bat (Rousettus amplexicaudatus) by scanning electron microscopy and light microscopy

Abstract

This study was carried on the tongues of ten normal, healthy and adult fruit bats (Rousettus amplexicaudatus, also known as the nyap biasa bat) in Yogyakarta, Java Island, Indonesia. The tongue was protrusible, elongated and flat with a rounded apex, and its width and thickness increased gradually towards to lingual root. There were two main types of lingual papillae, mechanical (filiform) and gustatory (fungiform and circumvallate). The tongue was divided into three parts (apex, corpus and radix), and then, each part was subdivided into three regions (two lateral regions and a median region). There were six subtypes of the filiform papillae—three types on the anterior part (small, scale‐like and giant), one type on the middle part (leaf‐like papillae) and two types on the posterior part (rosette‐shaped filiform and conical filiform papillae)—in addition to transitional papillae presented on the corpus and radix. Two types of gustatory papillae were represented by a small number of fungiform papillae that are scattered among the filiform papillae on the lingual apex and corpus, while three circumvallate papillae on the posterior part are arranged in a “V” shape pointing directly at the larynx.

Anatomical and surface ultrastructural investigation of the tongue in the straw‐coloured fruit bat (Eidolon helvum, Kerr 1972)

“…Earlier studies on the tongue of some species of nectarivory, frugivory and insectivory showed remarkable variations in lingual papillae resulting from adaptations to the intake of liquid and semi‐liquid food relative to varying seasonal environmental needs (Abumandour & El‐Bakary, 2013; Abumandour, 2014; Emura et al., 2001; Emura, 2009; Heiss et al., 2017; Kobayashi & Shimamura, 1982; Mqokeli & Downs, 2013; Sharma et al., 1999; Taki‐El‐Deen et al., 2013). The present report showed some structural features similar to those seen in fruit‐eating bats previously studied (Birt et al., 1997; Emura et al., 2001; Gunawan et al., 2019; Jackowiak et al, 2009; Shindo et al., 2009; Trzcielinska‐Lorych et al., 2009). Such remarkable similarities as shape and size, variable forms of mechanical papillae (filiform and conical); location, distribution and number of gustatory fungiform and vallate papillae, and with their taste buds (and taste pores) seem to reflect the adaptation of the E. helvum to fruit diets and their ability to switch between diet of fruit, nectar and/or leaves depending on seasonal availability of food type in the challenging tropical West African rain forests habitat.…”

“…These pronged (forked) papillae are common to the frugivorous, nectarivorous and some insectivorous bats (Abumandour & El‐Bakary, 2013; Masuko et al., 2007; Shindo et al., 2008), with minor variations in the number of their projections (processes) for grabbing and crushing their food. In addition, the function of the giant trifid filiform papillae has been speculated to increase the surface area during collection of nectar (Gunawan et al., 2019). The mechanical crowned‐filiform type with filamentous secondary processes assists in trapping fruit juices and other fluids by increasing surface tension (Sharma et al., 1997).…”

Identification of the Lingual Papillae in the sugar glider (Petaurus breviceps) by scanning electron microscopy and light microscopy

“…This feature has been explained before (Iwasaki et al, 2019) in higher primates and can be regarded as a degeneration of the role of the tongue in food uptake, which is similar in the sugar glider's tongue; the sugar glider's hands take part in handling foods (Smith, 2019). The body of the tongue is characterized by the presence of the sulcus medianus linguae that are also present in other animals: the brush-tailed kangaroo (Shoichi Emura et al, 2014), polar bear (Shoichi Emura et al, 2017), and fruit bat (Gunawan et al, 2019), although the location of the sulcus differs. Meanwhile, in animals such as the cape hyrax (Yoshimura et al, 2008), the sulcus medianus linguae is not visible.…”

Morphological characterization of Horsfield’s treeshrew Tupaia javanica lingual papillae: Light microscopy and scanning electron microscopy studies

“…Tongues were washed with physiological saline and dehydrated using a graded series of ethanol (KgaA, Darmstadt). They were then trimmed in the border of apex and corpus, fixed on metal plates, vacuum‐dried (25℃, 4 Pa; Buehler 1,000 Vacuum System, Stuttgart) and then coated with platinum with an ion coater (JEC‐3000FC, JEOL) before being observed using a scanning electron microscope with 15 kV voltage (Gunawan 2019).…”