SEM study on the dorsal lingual surface of the lesser dog-faced fruit bat, Cynopterus brachyotis.

The dorsal lingual surface of the lesser dog-faced fruit bat was examined by scanning electron microscopy (SEM). Filiform (Fi), fungiform (Fu) and vallate papillae (V) were observed. The Fi papillae were distributed over the entire dorsal surface of the tongue. The Fi papillae notably differed in morphology by their location on the tongue and could be classified into 5 types: 1) crown-like papillae, 2) giant trifid papillae, 3) scale-like papillae, 4) small conical papillae, and 5) large conical papillae. The Fu papillae were present rounded bodies on the anterior 2/3 of the tongue. The lesser dog-faced fruit bat showed the triangular arrangement of the three V, with the apex of the triangle directed posteriorly.     

Morphology of the dorsal lingual papillae in the bush dog (Speothos venaticus)

The dorsal lingual surface of a bush dog (Speothos venaticus) was examined by scanning electron microscopy (SEM). The tongue was about 7 cm in length. Filiform, fungiform and vallate papillae were found. The filiform papillae were distributed over the entire dorsal surface of the tongue. Each filiform papillae on the apical surface of the tongue had several conical processes, in the midportion were larger than those on the apex in size. In the region of the vallate papillae, the filiform papillae had not the conical processes and more larger than those on the midportion of the tongue. The fungiform papillae were present rounded bodies and more densely distributed on the tip of the lingual apex. There were 5 vallate papillae on both sides. The vallate papillae were located on both sides of the posterior end of the lingual body. Each papilla was surrounded by a groove and a crescent pad. In the dorsal surfaces of the papillae, small conical papillae were observed.     

The scanning electron microscopic study of lingual papillae in the silver fox (Vulpes vulpes fulva, Desmarest, 1820)

The tongues of adult silver foxes were studied using scanning electron microscopy. Five types of lingual papillae were found on the dorsal surface of the tongue. The most numerous papillae were filiform papillae covering the apex and body of the tongue. The filiform papillae on the anterior part of the tongue are divided into 1 main and 10-12 accessory processes. In the posterior part of the body of the tongue the number of accessory processes is reduced. Fungiform papillae are located between the filiform papillae. A cluster of 12 large fungiform papillae was found on the apex of the tongue. Conical papillae are located in the area of the vallate papillae and cover the posterior part of the root of the tongue. Their size increases towards the pharynx, where they are distributed more sparsely. In the silver foxes there were two pairs of vallate papillae. The wall surrounding each papilla and its gustatory trench forms partly connected 6-8 conical papillae. The foliate papillae on both margins of the tongue body are small and consist of 4-5 laminae. The distribution and type of lingual papillae found in the silver fox are similar to those in the other species belonging to the family Canidae.     

Morphology of the dorsal lingual papillae in the barbary sheep, Ammotragus lervia

The dorsal lingual surface of a barbary sheep (Ammotragus lervia) was examined by scanning electron microscopy (SEM). The tongue was about 20 cm in length. There were about 30 vallate papillae on both sides. Filiform, conical, fungiform and vallate papillae were found. The filiform papillae were distributed over the entire dorsal surface of the tongue, excepted for the lingual torus where conical papillae were present. The fungiform papillae were present rounded bodies, and more densely distributed as compared to that of the lingual body on the tip and ventral surface of lingual apex. No foliate papillae were seen on the dorsal surface. The vallate papillae were located on both sides of the midline in the caudal part. Each papilla was surrounded by a groove. These findings indicate that the tongue of the barbary sheep is similar to that of the formosan serow, japanese serow and blackbuck.     

Morphology of the lingual papillae in the raccoon dog and fox

The dorsal lingual surfaces of the raccoon dogs (Nyctereutes procyonoides) and fox (Vulpes vulpes japonica) were examined by scanning electron microscopical (SEM) observations. The distribution and type of the lingual papillae found in the raccoon dog were similar to those in the fox. Filiform, fungiform, foliate and vallate papillae were observed. The filiform papillae were distributed over the entire dosal surface of the tongue. Each filiform papilla on the apical surface of the tongue had several pointed processes. The filiform papillae of the lingual body consisted of a main papilla and some secondary papillae. The fungiform papillae were present rounded bodies, and more densely distributed on the lingual apex. The foliate papillae were seen on the dorsolateral aspect of the tongue. The vallate papillae were located on both sides of the posterior end of the lingual body. Each papilla was surrounded by groove and crescent pad. On the periphery of the papillae, large conical papillae were observed.     

Morphology of the dorsal lingual papillae in the blackbuck, Antilope cervicapra

The dorsal lingual surface of a blackbuck (Antilope cervicapra) was examined by scanning electron microscopy (SEM). The tongue was about 125 mm in length. There were about 30 vallate papillae on both sides. Filiform, conical, fungiform and vallate papillae were found. The filiform papillae were distributed over the entire dorsal surface of the tongue, excepted for the lingual torus where conical papillae were present. The fugiform papillae were present rounded bodies, and more densely distributed on the tip and ventral surface of ligual apex. No foliate papillae were seen on the dorsal surface. The vallate papillae were located on both sides of the midline in the caudal part. Each papilla was surrounded by a groove. These findings indicate that the tongue of the blackbuck is similar to that of the formosan and japanese serow.     

Light and scanning electron microscopic study on the lingual papillae and their connective tissue cores of the Cape hyrax Procavia capensis

We examined the epithelial surface and connective tissue cores (CTCs) of each lingual papilla on the Paenungulata, Cape hyrax (Procavia capensis), by scanning electron microscopy and light microscopy. The tongue consisted of a lingual apex, lingual body and lingual root. Filiform, fungiform and foliate papillae were observed on the dorsal surface of the tongue; however, fungiform papillae were quite diminished on the lingual prominence. Moreover, no clearly distinguishable vallate papillae were found on the tongue. Instead of vallate papillae, numerous dome-like large fungiform papillae were arranged in a row just in front of the rather large foliate papillae. Foliate papillae were situated in the one-third postero-lateral margin of the lingual body. The epithelium of filiform papillae was covered by a keratinized layer with kerato-hyaline granules, whereas weak keratinization was observed on the interpapillary epithelium. The external surface of the filiform papillae was conical in shape. CTCs of the filiform papillae were seen as a hood-like core with a semicircular concavity in the anterior portion of each core. Large filiform papillae were distributed on the lingual prominence. The CTCs of large filiform papillae after exfoliation of their epithelium consisted of a concave primary core and were associated with several small protrusions. The surface of fungiform papillae was smooth and dome-like. After removal of the epithelium, CTCs appeared as a flower bud-like primary core and were associated with several protrusions that were arranged on the rim of the primary core. Several taste buds were found on the top of the dorsal part of the epithelium of both fungiform and large fungiform papillae. Well-developed foliate papillae were seen and numerous taste buds could be observed in the lateral wall of the epithelium in a slit-like groove. The morphological characteristics of the tongue of the Cape hyrax had similarities with other Paenungulata such as Sirenia. However, three-dimensional characteristics, especially CTCs of lingual papillae, exhibited multiple similarities with rodents, insectivores and artiodactyls.     

Morphology of the lingual papillae in the Patagonian cavy

We examined the dorsal lingual surfaces of an adult Patagonian cavy (Dolichotis patagonum) by scanning electron microscopy. The tongue of the Patagonian cavy is about 8 cm long and the lingual body had lingual prominence on the posterior third. There were no fungiform papillae in the lingual dorsal surface. The fungiform papillae were observed in both lateral sides of the lingual apex. The filiform papilla of the lingual body consisted of a large conical papilla. The connective tissue core of the filiform papilla showed many slender processes. The fungiform papillae were round in shape. The connective tissue core of the fungiform papilla was flower-bud shaped. Two vallate papillae were located on between lingual body and root, and insert in two grooves. The connective tissue core of the vallate papilla was covered with numerous small spines. Many foliate papillae were observed on the posterolateral regions of the tongue. After removing epithelium from the foliate papillae many vertical depressions became apparent. These findings suggest that in the structure of the lingual papillae of the Patagonian cavy there is similar to that of the capybara.     

Scanning electron microscopy study of the tongue and lingual papillae of the California sea lion (Zalophus californianus californianus)

We observed the three-dimensional structures on the external surface and the connective tissue cores (CTCs) of the California sea lion (Zalophus californianus californianus), after exfoliation of the epithelium of the lingual papillae (filiform, fungiform, and vallate papillae), using scanning electron microscopy (SEM) and conventional light microscopy. Macroscopically, the tongue was V-shaped and its apex was rounded. At the posterior area of the tongue, five vallate papillae were arranged in a V shape. In the epithelium, numerous taste buds were distributed on the top of the vallate papillae. On the dorsal surface from the apex to the boundary between the anterior and posterior tongue, filiform papillae were densely distributed. The CTCs of the filiform papillae consisted of a main protrusion (primary core) and many small cores (secondary cores). From the apex to the anterior one-third of the tongue, dome-like fungiform papillae were densely distributed, whereas fewer were located at the posterior two-thirds of the tongue. Several taste buds were found in the epithelium on the fungiform papillae. The size of the filiform papillae gradually increased from the apex to the boundary between the anterior and posterior tongue. At the lingual radix, the conical papillae, which were bigger than any filiform papillae, were densely distributed. The morphological characteristics of the tongue of the California sea lion appear to have been transformed to adapt to an aquatic environment; however, they possess some structures similar to those of land mammals.     

Morphology of the lingual papillae in the Japanese marten

The dorsal lingual surfaces of two adult Japanese marten (Martes melampus) were examined by scanning electron microscopy (SEM). Filiform, fungiform, vallate and foliate papillae were observed. A small filiform papilla on the apical surface of the tongue had several pointed processes. A small filiform papilla contained the connective tissue core consisting of several small processes. A large filiform papilla of the lingual body consisted of a main papilla and some secondary papillae. A large filiform papilla contained the connective tissue core consisting of processes of various size. The fungiform papillae are round in shape. The connective tissue core of the fungiform papilla had a top with several round depressions. The four vallate papillae were located on both sides of the posterior end of the lingual body and each papilla was surrounded by groove and crescent pad. A zigzag surface structure appeared on the connective tissue core of the vallate papilla. The foliate papillae were seen on the dorsolateral aspect of the tongue and some ridges and grooves were exposed reciprocally. A zigzag surface structures appeared on the connective tissue cores of the ridges of the foliate papillae.     

Scanning electron microscopic study on the tongue and lingual papillae of the adult Spotted seal, Phoca largha

We observed the external surface and connective tissue cores (CTCs) of the lingual papillae (filiform, fungiform and vallate papillae) of adult Spotted seals (Phoca largha) using SEM and light microscopy. The tongue was V-shaped and its apex was rather rounded. On the dorsal surface from apex to the one-third posterior of the tongue, the lingual mucosa was densely covered by filiform papillae, with a scatted distribution of dome-like fungiform papillae, which have orthokeratinized epithelium. At the posterior part of the tongue, filiform papillae were totally diminished and their epithelium was parakeratinized. Approximately 6-7 vallate papillae were arranged in a V-shape on the posterior of the tongue. After removal of the epithelium, the CTCs of the filiform papillae that were distributed at apex consisted of a primary core and approximately 5-6 rod-shaped small accessory cores. The CTCs of filiform papillae that were distributed at anterior part of the tongue lacked primary protrusions and possessed approximately 10-15 rod shaped small accessory cores that were arranged in a horseshoe manner. The CTCs offungiform papillae had cylindrical primary cores and were fringed with accessory protrusion. In the Vallate papillae, taste buds were only seen at the dorsal epithelium.     

SEM study on the dorsal lingual surface of Microtus montebelli

The dorsal lingual surface of Microtus montebelli was examined by scanning electron microscopy (SEM). The filiform papillae were distributed over the entire dorsal surface of the tongue. The filiform papillae notably differed in morphology by their location on the tongue and could be classified into 4 types: 1) simple conical papillae, 2) true filiform papillae, 3) giant conical papillae, and 4) saw-like papillae. The fugiform papillae were present rounded bodies scattered over the anterior dorsal surface of the tongue. A vallate papilla was located at the middle end of the lingual body. The surface of the radix zone was smooth and without lingual papillae.     

Morphology of the lingual papillae in the tiger

The dorsal lingual surfaces of an adult tiger (Panthera tigris altaica) was examined by macroscopical and scanning electron microscopical observations. Filiform, fungiform and vallate papillae were observed. The filiform papillae were distributed over the entire dosal surface of the tongue. The fungiform papillae were present rounded bodies, and more densely distributed on the lingual apex. There were 4 vallate papillae in total on borderline between the lingual body and lingual radix. Each papilla was surrounded by a groove. No foliate papillae were seen on the dorsal surface. Openings of the glandular ducts on the regions of the vallate papillae were found.     

SEM study on the dorsal lingual surface of the nutria, Myocastor coypus

The dorsal lingual surface of prenatal and postnatal nutria was examined by scanning electron microscopy (SEM). Filiform (Fi), fungiform (Fu), foliate (Fo) and vallate papillae (Va) were observed. The Fi differed in morphology by their location on the tongue and could be classified into 3 types: 1) conical, 2) long, and 3) short filiform papillae. The Fu were scattered among the Fi. Many Fo were observed on the posterolateral regions of the tongue. There were 2 Va separating the anterior 2/3 from the posterior 1/3 of the tongue. The rudiments of Fu, Fo and Va were visible earlier than those of the Fi.     

Morphology of the dorsal lingual papillae in the newborn panther and Asian black bear

The dorsal lingual surfaces of a newborn panther (Panthera pardus) and two newborn asian black bears (Selenarctos thibetanus) were examined by scanning electron microscopy (SEM). The tongues of the panther and asian black bear were about 40 mm in length and about 20 mm in width. Filiform, fungiform and vallate papillae were found. The filiform papillae were distributed over the entire dorsal surface of the tongue. In the panther, the filiform papillae on margin of the lingual apex were divided into two shapes which were horny or club-shaped papillae. The filiform papillae on the midportion were larger than those on the lateral region in size. The fungiform papillae also were divided into two shapes which were hemispherical or club-shaped papillae. In the asian black bear, the filiform papillae on the margin of the lingual apex were larger than those on margin of the panther tongue. The vallate papillae in the animals of two species were located on both sides of the posterior end of the lingual body. Each papilla was surrounded by a groove and crescent pad.     

Light and scanning electron microscopic study on the tongue and lingual papillae of the common raccoon, Procyon lotor

We observed the external surface and connective tissue cores (CTCs), after exfoliation of the epithelium of the lingual papillae (filiform, fungiform, foliate and vallate papillae) of the common raccoon (Procyon lotor) using scanning electron microscopy and light microscopy. The tongue was elongated and their two-third width was almost fixed. Numerous filiform papillae were distributed along the anterior two-thirds of the tongue and fungiform papillae were distributed between the filiform papillae. Eight vallate papillae that had a weak circumferential ridge were distributed in a V-shape in the posterior part of the tongue and numerous taste buds were observable in the circumferential furrows of vallate papillae. Weak fold-like foliate papillae were observable at the lateral edge in the posterior part of the tongue and a few salivary duct orifices were observable beneath the foliate papillae. An islet-like structure with numerous taste buds, was observable on the deep part of the salivary duct of foliate papillae. Large conical papillae were distributed at the posterior part and root of the tongue. After removal of epithelium, filiform papillae of CTCs were appeared to be a thumb or cone-like main core and associating several finger-like short accessory cores. These cores were surrounded an oval concavity. The main core was situated behind the concavity and associated with accessory cores. CTCs of fungiform papillae were cylinder-like with numerous vertically running ridges and with a few concavities seen at the top of the cores. CTCs of vallate papillae and their surrounded circumferential ridge were covered with numerous pimple-like protrusions. The lingual papillae of Common raccoon's tongue had morphological feature of carnivore species.     

Morphology of the lingual papillae and their connective tissue cores in the cape hyrax

The dorsal lingual surfaces of four adult cape hyraxes (Procavia capensis) were examined by scanning electron microscopy (SEM). Filiform, fungiform and foliate papillae were observed. The lingual body had lingual torus on the posterior third. In the lateral sides of the tongue large fungiform papillae were observed and in the lateral sides of the torus very developmental foliate papillae were observed. Many fungiform papillae were observed in the ventral surface of the lingual apex. No vallate papillae were seen on the dorsal surface. The filiform papilla on the apical surface of the tongue had shovel-shaped papilla. The filiform papilla contained the connective tissue core consisting of some processes. The connective tissue core of the fungiform papillae was floral bud in shape. In the surface of the lingual torus numerous dome-shaped papillae are found. The dome-shaped papilla contained the connective tissue core consisting of a zigzag surface structure and the connective tissue core is surrounded by the processes of various sizes. In the surface of the lingual root numerous openings of the lingual glands were found. Around the glandular openings connective tissue ridges formed circular sheaths. In the lateral sides of the tongue large fungiform papillae were round in shape. The connective tissue core of the fungiform papilla was floral bud in shape. The foliate papillae were seen on the dorsolateral aspect of the tongue and some ridges and grooves were exposed reciprocally. Many small protrusions appeared on the connective tissue core of the ridge of the foliate papilla. These findings suggested that in the structure of the lingual papillae of the cape hyrax there was intermediate type between Rodentia and Artiodactyla.     

Comparative morphological study on the lingual papillae and their connective tissue cores in rabbits

The morphological structure of the lingual papillae and their connective tissue cores (CTC) in a rabbit were studied using LM and SEM and were compared to that of other animal species. Externally, the filiform papillae distributed on the anterior surface of the dorsal tongue were short and conical with a round base and had a flat area on their anterior upper half. The CTC of the conical filiform papillae had a roughly triangular plate-like structure with a round top. Several small round protrusions were found on both inclined planes of the triangle. Spearhead-like filiform papillae were distributed on the anterior edge of the lingual prominence and branched filiform papillae were on the posteriorly wide area of the prominence. These papillae on the prominence had a slightly ramified CTC that differed from that of the CTC of the conical filiform papillae distributed on the anterior tongue. Dome-like fungiform papillae were distributed among the conical filiform papillae of the anterior tongue and had a CTC with a roundish structure that was almost but, not quite spherical in appearance with 1 to 10 small round concave indentations for taste buds on their upper surface. The foliate papillae had approximately 15 parallel ridges separated by grooves. These ridges contained a parallel thin plate-like CTC exhibited after removal of the epithelium. The vallate papilla was comprised of a spherical central papilla and had a circular wall with a flower-like CTC almost resembling a carnation. The stereostructure of the rabbit's filiform CTC are comparatively described as being morphologically in between those of rodents and those of the guinea pig and Japanese serow. Such evolution has probably occurred due to the species unique masticatory and gustatory needs and functions.     

Morphological characteristics of the tongue and lingual papillae of the large bamboo rat (<Emphasis Type="Italic">Rhizomys sumatrensis</Emphasis>)

The large bamboo rat (Rhizomys sumatrensis) is a fossorial rodent found throughout Indochina that has a distinct habitat dominated by bamboo thickets. In the study reported here, the lingual biology of this rodent is described in detail, based on characteristic features of the tongue and lingual papillae as determined by light and scanning electron microscopy studies. The tongue was found to be elongated with a rounded apex and possessed a median groove and a well-developed intermolar prominence. Three types of the papillae were found on the dorsal lingual surface: filiform, fungiform and vallate papillae. The most abundant papillae were the filiform papillae, the majority of which had a wide base and fork-like processes. Rounded fungiform papillae with one to four taste buds were randomly distributed among the filiform papillae, with a high density found at the anterior tongue, particularly the apex. Two oval vallate papillae were observed on the posterior part of the tongue, surrounded by a circumferential groove into which their numerous gustatory pores opened. The lingual radix had no papillae but contained mucus-secreting Weber’s salivary glands. Structural adaptations of the tongue to meet the functional demands of food ingestion and food manipulation in the oral cavity are also discussed.