Histo-morphological comparison of the tongue between grainivorous and insectivorous birds / Comparación histo-morfológica de la lengua entre aves granívoras e insectívoras

SUMMARY: The study aimed to illustrate the influence of feeding habits in the anatomical feature and histological structure as well as some histochemical observations on the tongue of two species of birds which differ in their classification, activity and habitat as; The domestic pigeon, Grainivorous bird, and cattle egret, Insectivorous bird, using light and SEM studies. Results showed that the tongue of two species was differing in size, shape and structure. The tongue of pigeon appeared short and triangular; while in cattle egret was long lanceolate in shape with narrow tapering apex. Dorsal large conical lingual papillae presented between the body and the root of both tongue of the studied birds. They were arranged in form of U-letter in pigeon and in form of wide V-letter in cattle egret. Histologically, both dorsal and ventral lingual surfaces lined with keratinized stratified squamous epithelium, which decreased in the thickness and the degree of keratinization toward the base. The dorsum of the apex of pigeon tongue showed desquamated epithelial cells with filiform papillae, these papillae not observed in the egret¢s tongue. The tongue of cattle egret contained longitudinal tendinous tissue as intra-lingual ligament appeared parallel and accompanied with skeletal muscle bundles and attached with entoglossal cartilage. It extended longitudinally from the root to the body of the egret's tongue. The salivary glands presented in the propria submucosal layer of the dorsal surface that extended laterally from apex to the root, while the ventral surface devoid from any glandular structures. The nature of lingual salivary glands showed variations in their histochemical observation to Alcian blue stain and PAS technique. It has been summarized that the morphological and histological variations of both tongues may be correlated to their feeding habits.

RESUMEN: La investigación tuvo como objetivo ilustrar mediante estudios de luz y SEM, la influencia de los hábitos alimentarios en la característica anatómica y estructura histológica, así como algunas observaciones histoquímicas en la lengua de dos especies de aves, que se diferencian en su clasificación, actividad y hábitat, como es la paloma doméstica, ave granívora y la garcilla bueyera, ave insectívora. De acuerdo a los resultados la lengua de las dos especies difería en tamaño, forma y estructura. La lengua de las palomas tenía una forma corta y triangular; mientras que en la garceta bueyera era de forma larga lanceolada con ápice estrecho y agusado. Grandes papilas dorsales linguales cónicas entre el cuerpo y la raíz de ambas lenguas estaban dispuestos en forma de letra U en paloma y en forma de letra V ancha en garza bueyera. Histológicamente, las superficies linguales dorsal y ventral estaban revestidas con epitelio escamoso estratificado queratinizado que disminuía en el grosor y el grado de queratinización hacia la base. El dorso del ápice de la lengua de la paloma mostró células epiteliales descamadas, estas papilas no se observaron en la lengua de la garceta. Se observó tejido tendinoso longitudinal en la lengua de la garceta bueyera, debido a que el ligamento intralingual aparecía en forma paralela y acompañado de haces de músculo esquelético y adherido con cartílago entogloso. Se extendía longitudinalmente entre la raíz hasta el cuerpo de la lengua de la garceta. Las glándulas salivales de la lengua estaban incrustadas en la capa submucosa propia de la superficie dorsal que se extendía lateralmente desde el ápice hasta la raíz, mientras que la superficie ventral carecía de estructuras glandulares. En las glándulas salivales linguales se observaron variaciones histoquímicas a la tinción con azul de Alcian y la técnica PAS. En conclusión, las variaciones morfológicas e histológicas de ambas lenguas pueden estar correlacionadas con sus hábitos alimentarios.

Structural and ultrastructural characteristics of the tongue of the Collared Peccary (Pecari tajacu, Linnaeus, 1758).

The tongue is an important organ in species due to its feeding functions, and its structure is influenced by the habitat and diet. The Collared Peccary (Pecari tajacu, Linnaeus, 1758) is a terrestrial mammal that is distributed on the American continents and has an omnivorous diet. This study aimed to describe the morphological characteristics of the tongue, lingual papillae and the connective tissue cores (CTCs) of the Collared Peccary. Eight tongues were collected from the Wild Animals Multiplication Center. The samples (n = 6) were processed for three-dimensional analysis of their dorsal epithelium, and their CTCs by scanning electron microscopy and the other samples (n = 2) were used to observe ultrastructural characteristics by transmission electron microscopy. Filiform papillae were observed in the lingual apex and body with their conical CTC demonstrating ripples in their extent. Two types of fungiform papillae were observed, the first in the apex and body with a dome-shaped CTC and the second forming a dorsolateral line with a radial pattern CTC. The vallate papillae were bilateral in the caudal region with the CTCs, characterised by numerous projections, and foliate papilla were not observed. We found a new type of papilla anteriorly to the vallate papilla with an irregular groove and a CTC formed by triangular-shaped projections with a duct opening at the top. We concluded that the lingual papillae of the Collared Peccary resemble those papillae of other mammals, however, were revealed another form of their CTCs and a new lingual papillae morphological description.

Papillary architecture in the tayra tongue.

The tayra (Eira barbara) is a mammal belonging to the Mustelidae family that occurs in all Brazilian biomes. The present work aimed to describe the morphology of the tongue of these specimens highlighting their structures and particularities that will serve as a subsidy to elucidate the anatomy of the same and for comparative studies among other species of domestic and wild animals. Five adult male specimens of E. barbara were studied, which were fixed using 10% aqueous formaldehyde solution. The tongue was removed by opening the oral cavity and separating the maxillary/mandible bone complex. Being in possession of the material, photodocumentations and collection of the fragments were made for the proper preparation of histological slides and Scanning Electron Microscopy (SEM). The lingual papillae found in tayra were mechanical: filiform and conical; and gustative: fungiform and circumvallated. Histologically, the papillae are constituted by keratinized stratified epithelium and in the innermost region, it was composed of tissue connective dense unshaped followed by a layer of muscle bundles of skeletal striated. In the region of the root of the tongue of E. barbara, there were a set of small mixed salivary glands (serous and mucous) and the punctual presence of gustatory corpuscles at the level of epithelium. The morphological description of the E. barbara tongue revealed similarity to that described in literature for other domestic and wild mammals. However, the particularity of the absence of foliate papilla and the quantitative of four papillae circumvallate in the region of the root of the tongue of this species.

Morphology of the tongue of Vermilingua (Xenarthra: Pilosa) and evolutionary considerations.

The tongue of anteaters (Xenarthra, Pilosa, Vermilingua) is a highly specialized for myrmecophagy. Here, we describe the topography and histology of the tongue, and compare it to that of other xenarthrans and other myrmecophagous eutherian mammals. The tongue of Vermilingua is long and slender, with an apical protuberance, which differs between Myrmecophagidae and Cyclopes didactylus. In the former, the rostral region is conical, and in the latter, it is dorsoventrally compressed, as observed in sloths. The tongue of Vermilingua has filiform and circumvallate papillae on the surface; foliate and fungiform papillae are absent. The filiform papillae of Myrmecophaga tridactyla are simple all over the tongue, differing from Tamandua tetradactyla and Cyclopes didactylus, which present composed filiform papillae in the rostral and middle regions. Histologically, the tongue has a peculiar organization of muscular and neurovascular tissues, differing from the usual mammalian pattern. However, the tongue structure is less divergent in Cyclopes. The presence of two circumvallate papillae is common to the three major clades of Xenarthra (Cingulata, Folivora and Vermilingua). In each group, the tongue may reflect functional features related to myrmecophagous (anteaters and some armadillos), omnivorous (remaining armadillos) and folivorous (sloths) feeding habits. The similarities between the tongues of Vermiligua and other non-xenarthran eutherian myrmecophagous mammals are somewhat general and, under close inspection, superficial, being an example of different lineages achieving the same morphofunctional adaptations through distinct evolutionary pathways.

Scanning electron microscopy study of the dorsal surface of the tongue in the slow loris (Nycticebus coucang) and pygma slow loris (N. Pygmaeus) / Estudio de microscopía electrónica de barrido de la superficie dorsal de la lengua en lori perezoso (Nycticebus coucang) y lori perezoso pigmeo (N. Pygmaeus)

The dorsal surface of the tongues of the Slow Loris and the Pygma Slow Loris were examined by employing scanning electron microscopy techniques. Three types of the papillae are present on their dorsal surface of the tongue: filiform, fungiform and vallate. The filiform papillae are located the apex and the body of the tongue, and we observed that each of them has a gustatory pore. The fungiform papillae, scattered singly among the filiform papillae, distribute mainly on the apex of the tongue. The vallate papillae are located along the diversing arms of the V-shaped boundary between the anterior and posterior regions of the tongue. In addition, no foliate papillae were observed. The morphological characteristics of the dorsal surface of the tongues in Slow Loris and Pygma Slow Loris are similar to each other.

La superficie dorsal de la lengua en lori perezoso y lori perezoso pigmeo fue examinada utilizando técnicas de microscopía electrónica de barrido. Se observaron tres tipos de papilas presentes en la superficie dorsal de la lengua: filiforme, fungiforme y valada. Las papilas filiformes se localizaban en el ápice y en el cuerpo de la lengua, y observamos que cada una tenía un poro gustativo. Las papilas fungiformes están distribuidas individualmente entre las papilas filiformes, principalmente en el ápice de la lengua. Entre las regiones anterior y posterior de la lengua se observan las papilas valadas a lo largo de las extensiones del margen en forma de 'V'. Además, no se observaron papilas foliadas. Las características morfológicas de la superficie dorsal de las lenguas en lori perezoso y lori perezoso pigmeo son similares entre sí.

Morphologic effects of filiform papilla root on the lingual mechanical functions of Chinese yellow cattle / Efectos morfológicos de las raíces de las papilas filiformes sobre la función mecánica lingual del ganado amarillo chino

The morphology of filiform papilla root in the tongue of Chinese yellow cattle were studied by scanning electron microscopy, and several geometric models were established to analyze the possible effects of such structures on lingual mechanical functions. Conical and tongue-like filiform papillae were detected in different locations on the lingual surface, along with six types of root structures. A lingual groove surrounded the papillae in five of these structures. To date, such grooves have not been discussed in studies on bovine lingual morphology, and those distributed on the dorsal surface of the lingual apex can limit the motion ranges of filiform papillae. Two secondary papillae emerged from a groove on the dorsal surface of the lingual apex's caudal half; these papillae can protect a filiform papilla root from damage. The grooves and the flat orientation of such papillae on the dorsal surface of the lingual body can reduce energy expenditure during forage transportation. A lingual rib that can strengthen the filiform papilla root emerged from a groove on the dorsal surface of the rostral half of the lingual body. On the dorsal surface of the lingual body's caudal half, all filiform papillae emerged from a groove to form low lingual walls that can protect the roots from being crushed by forage. High lingual walls were generated on the lateral surface of the lingual apex; these walls enable filiform papillae to adapt to harsh food environments effectively. The root structures on the lingual body's lateral surface were adequately simple and did not exhibit lingual grooves; thus, hydraulic resistance may decrease during mastication. Diverse root structures can optimize the lingual mechanical functions and improve self-protection capability in combination with the appearance and distributions of these papillae. All the aforementioned features may be the result of environmental adaption and cattle evolution.

La morfología de las papilas filiformes ubicadas en la raíz lingual del ganado amarillo chino fue estudiada mediante microscopía electrónica de barrido, estableciendo varios modelos geométricos para analizar los posibles efectos de estas estructuras sobre las funciones mecánicas linguales. Se detectaron papilas filiformes cónicas en diversas localizaciones de la superficie lingual, junto con seis tipos de estructuras en la raíz de la misma. Un surco lingual rodeado de las papilas se observó en cinco de estas estructuras. Hasta la fecha, dichos surcos no se han discutido en los estudios sobre la morfología lingual bovina, y aquellas distribuidas en la superficie dorsal de la cúspide lingual pueden limitar los rangos de movimientos en las papilas filiformes. Dos papilas secundarias surgieron de una ranura en la superficie dorsal de la mitad caudal de la cúspide lingual; estas papilas pueden proteger de los daños a una papila filiforme. Las ranuras y la orientación plana de tales papilas en la superficie dorsal del cuerpo lingual pueden reducir el gasto de energía durante el transporte de forraje. Un nervio lingual que puede fortalecer la raíz y las papilas filiformes se observó en una de las ranuras en la superficie dorsal, de la mitad rostral del cuerpo lingual. En la superficie dorsal de la mitad caudal del cuerpo lingual, todas las papilas filiformes generaron una ranura para formar un tipo de paredes linguales que pueden proteger las raíces. Las paredes linguales altas se generaron en la superficie lateral del ápice lingual; estas paredes permiten que las papilas filiformes se adapten a entornos inhóspitos de alimentos. Las estructuras de la raíz en la superficie lateral del cuerpo lingual fueron simples y no mostraron surcos linguales, lo que puede disminuir la resistencia hidráulica durante la masticación. Diversas estructuras de la raíz pueden optimizar las funciones mecánicas linguales y mejorar la capacidad de autoprotección en combinación con el aspecto y las distribuciones de estas papilas. Todas las características antes mencionadas pueden ser el resultado de la adaptación ambiental y la evolución de ganado.

Morphology of the lingual papillae in the least weasel (Mustela nivalis) / Morfología de las papilas linguales en la comadreja común (Mustela nivalis)

The dorsal surface structure of the lingual papillae in the least weasel was compared with that of other carnivorous mammalian species. Two types of mechanical papillae (filiform and conical) and two types of gustatory papillae (fungiform and vallate) were observed. The filiform papillae had secondary processes. Rarely conical papillae were observed. A few taste buds were seen on the surfaces of the fungiform papillae. The four vallate papillae were located on both sides of the posterior end of the lingual body. In conclusion, morphological characteristics of the lingual papillae and their distribution in the least weasel were similar to those of the Japanese marten and ferret. The conical papillae in the lingual apex of the Japanese marten and ferret were not observed, but the conical papillae were seen in the lingual apex of the least weasel.

La estructura de la superficie dorsal de las papilas linguales en la comadreja se comparó con la de otras especies de mamíferos carnívoros. Se observaron dos tipos de papilas mecánicas (filiformes y cónicas) y dos tipos de papilas gustativas (fungiformes y circunvaladas). Las papilas filiformes presentaron procesos secundarios. En raras ocasiones se observaron papilas cónicas. Unas pocas papilas gustativas fueron observadas en las superficies de las papilas fungiformes. Las cuatro papilas circunvaladas se encuentran a ambos lados de la parte posterior de la lengua. En conclusión, las características morfológicas de las papilas linguales y su distribución de la comadreja menor fueron similares a los de la marta y hurones japonés. No se observaron papilas cónicas en el ápice de la lengua de la marta y hurón japonés, pero si en el ápice de la lengua de la comadreja común.

Anatomical and Scanning Electron Microscopic Study of the Tongue in the Meerkat (Suricata suricatta, Schreber, 1776).

This research presents the first anatomical description of the tongue and lingual papillae of the meerkat and compares the different information on the morphology of the other carnivore species. For this purpose, three tongues were used as material. The tongue was elongated with an oval or rounded apex. On the dorsal and ventrolateral surfaces of the tongue, filiform papillae had extent variations in morphology. Papillary body of each filiform papilla on the ventrolateral surface of the lingual body was ramified into 2-5 glovelike projections, and all pointed tips of these projections were directed caudally. On the dorsal lingual surface, each filiform papilla leaned on another without any space and both lateral borders of each filiform papilla included 4-6 small secondary projections or spines. A few rounded fungiform papillae were randomly distributed and embedded among the filiform papillae. On the caudal one-third of the body, there were two elongated circumvallate papillae. Some superficial fissures and taste pores were detected on the flat surfaces of each circumvallate papilla which was surrounded by a prominent and continuous gustatory groove. On the radix of the tongue, numerous dome-shaped protuberances of lingual salivary glands beneath the epithelium and one centrally located orificium was very invincible on the convex surface of each protuberance. Anatomical distribution of lingual papillae differed from those of other carnivores and represented morphological adaptation to the food type and feeding habits.

Functional anatomical, histological and ultrastructural studies of three chameleon species: Chamaeleo chamaeleon, Chamaeleo africanus, and Chamaeleon vulgaris / Estudios anatómicos, histológicos y ultraestructurales funcionales de tres especies de camaleón: Chamaeleo chamaeleon, Chamaeleo africanus, y Chamaeleon vulgaris

Three chamaeleon species including Chameleon Chamaeleo chamaeleon, Chameleon Chamaeleo africanus, and Chamaeleon vulgaris were collected and their tongue were dissected and examined morphologically and investigated using light and scanning electron microscopy. Both species showed similar histological manifestation of lingual papillae and tubular glands with dense mucous secretion especially in Chamaeleon vulgaris. There is no keratinization of lingual surfaces. Ultrastructurally, filliform represent the only pattern of lingual pappillae and take either cylindrical, conical and leaflet structure.Although the examined chalmaeleon species collected from different habitat, it shows almost similarities in their histological and ultrastructural structures.

Fueron recolectadas tres especies de Camaleón incluyendo Camaleón Chamaeleo chamaeleon, Camaleón Chamaeleo africanus y Chamaeleon vulgaris. Se disecó su lengua y examinó morfológicamente mediante el uso de microscopía de luz y electrónica de barrido. Ambas especies mostraron características histológicas similares en relación a las papilas linguales y glándulas tubulares con secreción mucosa densa, especialmente el Chamaeleon vulgaris. No hubo queratinización de las superficies linguales. Ultraes-tructuralmente, el único patrón de papilas linguales fue el filiforme, tomando una estructura ya sea cilíndrica, cónica y de hoja. Aunque las especies de Camaleón examinadas se recogieron de diferentes hábitat, ellas mostraron similitudes en su estructura histológica y ultraestructural.

Morphology of the lingual surface of South American fur seal (Arctocephalus australis) and sea lion (Otaria flavescens).

In this study, we aimed to describe the morphological characteristics of the lingual papillae in two species of Otariidae family by stereomicroscopy and scanning electron microscopy. We used tongues of two South American Otariidae species. The tongues were elongated and terminated in bifid apex and there was no median sulcus on the dorsal lingual surface. The most numerous type of lingual papilla was filiform in the South American fur seal (SASL) and entire dorsal lingual surface was covered by these filiform papillae but the dorsal surface of the tongue of the South American sea lion was covered by numerous polygonal projections, which were different in size. Fungiform papillae were detected in only SASL and they randomly distributed on the lingual apex and body, and some fungiform papillae were collected into twosome or threesome groups on the posterior part of the lingual body. Circumvallate papilla was found in the center of the lingual radix of South American sea lion. Thread-like conical papillae were common for both species and they located on the lingual radix. We determined that lingual surface morphology was completely different in each species, although they were members of the same family, Otariidae.

Three-dimensional aspects of the lingual papillae and their connective tissue cores in the tongue of rats: a scanning electron microscope study.

The aim of the present study was to describe the tridimensional morphological characteristics of the lingual papillae and their connective tissue cores (CTCs) in Sprague Dawley rats. Four types of papillae were reported on the dorsal surface. Filiform papillae were distributed on the tongue surface and after epithelial maceration a conic and multifilamentary shape of the CTCs was revealed. Fungiform papillae were reported on the rostral and middle regions covered by a squamous epithelium. After the removal of the epithelium, the shape of a volcano with the taste orifice at its top was noted. Foliate papillae were composed of five pairs of epithelial folds situated on the lateral-caudal margin of the tongue. After the removal of the epithelium, they were shown to be limited by thin laminar projections. The vallate papilla with an oval shape was present in the caudal region and delimited by an incomplete groove. The morphological characteristics of the lingual papillae of Sprague Dowley rats, three-dimensional SEM images, and the types of papillae on the dorsal surface were similar to those reported previously in other rodent mammals. The maceration technique revealed the details of extracellular matrix with varied shapes form of connective tissue cores.

Morphological comparison of the filiform papillae of New Zealand white rabbits (Oryctolagus cuniculus) as domestic mammals and Egyptian fruit bat (Rousettus aegyptiacus) as wild mammals using scanning electron microscopic specimens / Comparación morfológica de las papilas filiformes de conejos blancos Nueva Zelanda (Oryctolagus cuniculus) como los mamíferos domésticos y los murciélagos de la fruta egipcios (Rousettus aegyptiacus) como los mamíferos salvajes utilizando muestras de microscopía electrónica de barrido

This paper presents a comparison of the morphological structure of the filiform papillae in New Zealand white rabbits as domestic mammals and Egyptian fruit bats as wild mammals. This study was carried out on the tongues of adult healthy New Zealand white rabbits and Egyptian fruit bats of both sexes. There were four types of lingual papillae in both animals. In the Egyptian fruit bats, there were six subtypes of the filiform papillae; three on the anterior part (small, conical and giant), two on the middle part (cornflower and leaf-like papillae) while the posterior part contain rosette shape filiform papillae, in addition to transitional papillae and conical papillae. In New Zealand white rabbits, there were four subtypes of filiform papillae; spoonful conical (on the lingual anterior part), processed (at the anterior edge of lingual prominence), leaf-like (on the posterior area of lingual prominence) and triangular filiform papillae (on the lingual root). The shape, size, number and orientation of the lingual papillae itself and its processes varied according to their location within the tongue (region-specific) in relation to the feeding habits, strategies for obtaining food, climate conditions, and types of food particles.

Se comparó la estructura morfológica de las papilas filiformes de un mamífero doméstico (conejo neozelandes) y de un mamífero silvestre (murciélagos de la fruta egipcio). El estudio fue realizado en animales de ambos sexos. Se observó cuatro tipos de papilas linguales, en ambas especies de animales. En los murciélagos de la fruta egipcio se observaron seis subtipos de papilas filiformes; tres en la parte anterior (pequeño, cónico y gigante), dos en la parte media (aciano y hojas como papilas) mientras que en la parte posterior se observaron papilas filiformes y papilas de transición cónica. En los conejos se observaron cuatro subtipos de papilas filiformes; cónica cucharada (en la parte anterior lingual), procesado (en el margen anterior de la prominencia lingual), tipo hoja (en la zona posterior de la prominencia lingual) y papilas filiformes triangulares (en la raíz lingual). La forma, tamaño, número y orientación de las papilas linguales y sus procesos varían de acuerdo a la función y a la ubicación en la lengua (específicos de la región) en relación con los hábitos de alimentación, las estrategias para la obtención de alimentos, las condiciones climáticas y tipos de partículas de alimentos.

Characteristics of the gustatory organs on the tongue of the chinese fire-bellied newt (Cynops orientalis): light and scanning electron microscopy study / Características de los órganos gustativos en la lengua del tritón vientre de fuego chino (Cynops orientalis): estudio por microscopía de luz y electrónica de barrido

The dorsal surface of the tongue gustatory organs of Chinese fire-bellied newt (Cynops orientalis) was observed by employing the light and scanning electron microscopy (SEM) techniques. The results revealed that the rostral and median part of the tongue presents a round apex and covered by taste disks (TDs). They are usually roundish or ellipsoidal in shape and are 20-35 mm in diameter. The many openings of the lingual glands are 4-8 mm in diameter exist in the lateral border or median part of lingual body. The gustatory organs on the tongue did not differed form those presented in other species in Caudates. These may indicate the functions of gustatory organs on the tongue related to their life habit.

La superficie dorsal de la lengua de los órganos gustativos del tritón de vientre de fuego chino (Cynops orientalis) se observó mediante microscopía de luz y electrónica de barrido (SEM). Los resultados revelaron que la parte rostral y mediana de la lengua presenta un ápice redondo y cubierto por discos sensoriales. Estos por lo general tienen una forma redondeada o elipsoidal con un diámetro de 20-35 mm. Las numerosas aperturas de las glándulas linguales tienen un diámetro de 4-8 mm en el margen lateral o en la parte mediana de cuerpo lingual. No se observaron diferencias en los órganos gustativos linguales al comparar estos con otras especies de caudados. Estos pueden indicar funciones de los órganos gustativos de la lengua relacionadas con su hábito de vida.

Ultrastructural aspects of the tongue in Magellanic Penguins Spheniscus magellanicus (Forster, 1781) / Aspectos ultraestruturais da língua de Pinguim-de-Magalhães Spheniscus magellanicus (Forster, 1781)

The tongue of birds presents diversified morphologic characteristics, related directly their feeding habits and may be adapted to food capture. Penguins of the Spheniscidae family are pelagic birds that are totally adapted to the marine environment.  The objective of this study was to describe the morphology of the tongue in Magellanic penguins (Spheniscus magellanicus). In order to investigate these characteristics, six tongues of juvenile S. magellanicus were collected and their morphology analyzed macroscopically and microscopically.  The tongue of the Magellanic penguin has a fusiform shape with a round apex that is narrower than the root, following the shape of the beak.  The epithelium of the tongue of the Magellanic penguin showed to be stratified and very keratinized, with the presence of lingual papillae that showed a caudally inclined apex. The neighboring connective tissue showed absence of mucous glands. The cartilaginous skeleton was observed in the medial region of the tongue, extending from the base to the apex. The structure of the tongue of the Magellanic penguin showed to be similar to that of other penguin species, but also showed peculiar characteristics that were not observed in other bird families.(AU)

A língua das aves apresenta características morfológicas diversificadas, relacionados diretamente com seus hábitos alimentares e pode ser adaptado para a captura de alimentos. Os pinguins da família Spheniscidae são aves pelágicas totalmente adaptadas ao ambiente marinho. O objetivo deste estudo foi descrever a morfologia da língua de pinguins de Magalhães (Spheniscus magellanicus). Para investigar tais características, seis línguas de S. magellanicus juvenis foram coletados e sua morfologia analisada macro e microscopicamente. A língua do pinguim de Magalhães tem formato fusiforme com ápice arredondado e mais estreito em relação à raiz, acompanhando o formato do bico. O epitélio da língua do pinguim-de-Magalhães mostrou-se estratificado e muito queratinizado, com a presença de papilas linguais, com ápices voltados caudalmente. O tecido conjuntivo adjacente mostrou ausência de glândulas mucosas. Um esqueleto cartilaginoso, formado por cartilagem hialina, foi observado na região mediana da língua se estendendo da base até ápice. A estrutura da língua do pinguim Magellanic mostrou ser semelhante ao de outras espécies de pinguins, mas também apresentou características peculiares que não foram observados em outras famílias de aves.(AU)

Structural and ultrastructural features of the agouti tongue (Dasyprocta aguti Linnaeus, 1766).

The agouti (Dasyprocta aguti Linnaeus, 1766) is a wild rodent belonging to the family Dasyproctidae that is found throughout Brazil and feeds on fruits and seeds. The aim of the present study was to describe the following features of the tongue of agouti: its morphological structures, the three-dimensional characteristics of the lingual papillae surface, the connective tissue cores (CTCs) and the epithelial cell ultrastructure. Four types of papillae were observed on the dorsal surface of the tongue with a triangular shape: filiform, fungiform, foliate and vallate. Filiform papillae were distributed throughout the tongue surface, and removal of the epithelial surface revealed conical CTCs and multifilaments. Fungiform papillae were observed in the rostral and middle regions, whereas foliate papillae developed in pairs on the lateral margin of the caudal region. Removal of the epithelium in these regions revealed CTCs with parallel laminar conformation. Vallate papillae were arranged in a V-shape in the caudal region, and their CTCs ranged in shape from elongate to ovoid. The ultrastructural components of the dorsal epithelium were the basal, spinous, granular and keratinised layers. A broad area with cytoplasmic projections was identified in the interface region between the lamina propria and the basal layer. Flattened cells with intermediate filaments were observed in the transitional region between spinous and granular layers. The keratinised layer was composed of superimposed epithelial cells where desmosomes and cell-surface microridges were observed. These structural features, including the three-dimensional aspects of the lingual papillae, the CTCs and the epithelial ultrastructure, indicate that when compared with other animals, particularly other rodent species, the morphological features of the tongue of agouti are relatively well developed, especially regarding foliate and vallate papillae.

Structural characterization of the capybara (Hydrochaeris hydrochaeris) tongue by light, scanning, and transmission electron microscopy.

Capybara is the largest rodent in the world and displays a seasonally dependent herbivore feeding behavior. Here, we present an anatomical contribution for understand this fact, by light, scanning, and transmission electron microscopy methodologies for tongue tissue analysis. The histological preparations revealed filiform, fungiform, vallate, and foliate papillae on the dorsal mucosa of the capybara tongue. The epithelial layer exhibited a lining of keratinized stratified squamous epithelial cells. The lamina propria was characterized by a dense connective tissue composed of the primary and secondary papillar projections. We also revealed the original aspects of the connective papillae. The shapes of the papillae varied by region of the tongue, and filiform, fungiform, vallate, and foliate papillae and subjacent layers of muscular fibers were observed. Pyriform taste buds occupying the epithelial layer of fungiform, vallate and foliate papillae were identified and the intracellular components of the taste buds and the intracorpuscular amyelinated nerve fibers were observed. The taste buds were characterized by the distribution of granular endoplasmic reticulum throughout the perinuclear area, the Golgi apparatus, and mitochondrial assemblies of various distinct diameters. Mitochondrial accumulation was also observed in the collagen bundle-surrounded amyelinated nerve fibers beside the basal cells. Therefore, these peculiar anatomical descriptions may contribute to understanding the adaptation of the feeding behavior of capybaras in a seasonally changing environment.

Gross and microscopic observations on the lingual structure of the Franciscana (Pontoporia blainvillei--Gervais and d'Orbigny, 1844).

In most anatomical studies developed with mammals, the tongue is described as highly differentiated among different species. However, studies on the tongue of aquatic mammals are still limited as compared to those on terrestrial mammals. The aim of this study was to describe the tongue morphology of the Franciscana dolphin (Pontoporia blainvillei) using macroscopic observations, light, and scanning electron microscopy. Microscopically, the dorsal surface was covered by a keratinized stratified epithelium. Salivary gland acini were found on the middle and caudal third of the tongue. The dorsal surface was totally covered by filiform papillae with a connective tissue core and a connective tissue structure round in shape in the middle and caudal regions.

Models hosts for the study of oral candidiasis.

Oral candidiasis is an opportunistic infection caused by yeast of the Candida genus, primarily Candida albicans. It is generally associated with predisposing factors such as the use of immunosuppressive agents, antibiotics, prostheses, and xerostomia. The development of research in animal models is extremely important for understanding the nature of the fungal pathogenicity, host interactions, and treatment of oral mucosal Candida infections. Many oral candidiasis models in rats and mice have been developed with antibiotic administration, induction of xerostomia, treatment with immunosuppressive agents, or the use of germ-free animals, and all these models has both benefits and limitations. Over the past decade, invertebrate model hosts, including Galleria mellonella, Caenorhabditis elegans, and Drosophila melanogaster, have been used for the study of Candida pathogenesis. These invertebrate systems offer a number of advantages over mammalian vertebrate models, predominantly because they allow the study of strain collections without the ethical considerations associated with studies in mammals. Thus, the invertebrate models may be useful to understanding of pathogenicity of Candida isolates from the oral cavity, interactions of oral microorganisms, and study of new antifungal compounds for oral candidiasis.

Ultrastructural aspects of Callithrix penicillata lingual papillae.

Callithrix penicillata belongs to the family Callitrichidae, Callithrix genus. They are basically insectivorous, but they consume fruits. The mucosa of the tongue is composed of some papillary types, revealing different levels of expertise. The present study attempted to describe the morphological and ultrastructural aspects of the dorsal surface of the C. penicillata, describing the characteristics and distribution of papillae found. Five tongues of C. penicillata (two females and three males), obtained from breeding colonies of CENP-Ananindeua-PA, died from natural causes. The material was fixed partly in a buffer solution paraformaldehyde 10% and partly in modified Karnovsky solution, divided into apex, body, and root, and then the fragments were used in light microscopy and scanning electron microscopy. The average length of the tongue of the females was 22 mm and for males 20.5 mm. Three types of papillae were described: filiform (along all tissue extension with 154 µm of diameter), fungiform (along all tissue extension with 275 µm of diameter), and vallate (just three units in caudal (dorsal) portion with 672 µm of diameter). Data analysis indicates that the distribution and ultrastructural morphology of the C. penicillata lingual papillae are some similar to other primates.

Studies on tongue of reptilian species Psammophis sibilans, Tarentola annularis and Crocodylus niloticus / Estudios sobre la lengua de las especies de reptiles Psammophis sibilans, Tarentola annularis y Crocodylus niloticus

Three different reptilian species Psammophis sibilans (Order Ophidia), Tarentola annularis (Order Squamata and Crocodylus niloticus (Order Crocodylia) are used in the present study. Their tongue is removed and examined morphologically. Their lingual mucosa examined under scanning electron microscopy (SEM) as well as processed for histological investigation. Gross morphological studies revealed variations of tongue gross structure being elongated with bifurcated end in P. sibilans or triangular flattened structure with broad base and conical free border in T. annularis or rough triangular fill almost the floor cavity in C. niloticus. At SEM, the lingual mucosa showed fine striated grooves radially arranged in oblique extension with missing of lingual papillae. Numerous microridges are detected above the cell surfaces in P. sibilans. T. annularis exhibited arrangement of conical flattened filiform papillae and abundant of microridges. However in C. niloticus, the lingual mucosa possessed different kinds of filiform papillae besides gustatory papillae and widespread arrangement of taste buds. Histologically, confirmed SEM of illustrating the lingual mucosa protrusion of stratified squamous epithelium in P. sibilans and presence of apical taste buds in conical filiform papillae of T. annularis. The lingual mucosa of C. niloticus revealed different forms of both filiform and gustatory papillae.

En el presente estudio fueron utilizados tres diferentes especies de reptiles Psammophis sibilans (Orden Ophidia), Tarentola annularis (Orden Squamata y Crocodylus niloticus (Orden Crocodylia). Sus lenguas fueron removidas y examinadas morfológicamente. Las mucosas linguales se examinaron bajo microscopio electrónico de barrido (SEM) y también procesadas para la investigación histológica. El estudio morfológico macroscópico reveló variaciones de la estructura de la lengua, siendo éstas alargadas con el extremo bifurcado en P. sibilans o de estructura triangular aplanada con una base amplia y el borde libre cónico en T. annularis o triangular rugosa llenando casi todo el suelo de la cavidad en C. niloticus. En el SEM, la mucosa lingual mostró finas ranuras estriadas dispuestas radialmente en la extensión oblicua con pérdida de las papilas linguales. Numerosas microcrestas fueron detectadas por encima de la superficie de las células en P. sibilans. T. annularis exhibiendo una disposición de papilas filiformes cónicas aplanadas y abundante de microcrestas. Sin embargo, en C. niloticus, la mucosa lingual posee diferentes tipos de papilas filiformes además de papilas gustativas con una extensa disposición de corpúsculos gustativas. Histológicamente, mediante confirmación de SEM se ilustra la protrusión del epitelio escamoso estratificado de la mucosa lingual en P. sibilans y la presencia de corpúsculos gustativos apicales en las papilas filiformes cónicas de T. annularis. La mucosa lingual de C. niloticus reveló diferentes formas de ambas papilas, filiformes y gustativas.