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Head morphology of C. flavomarginata and C. amboinensis. (A) Cuora flavomarginata, cranium lateral view; (B) Cuora flavomarginata, m. adductor mandibulae externus dorsal view; (C) Cuora amboinensis, cranium lateral view; (D) Cuora amboinensis, M. adductor mandibulae externus dorsal view. Scale bar ¼ 10 mm. aep, m. add. mand. externus pars profunda; aes, m. add. mand. externus pars superficialis; bo, os basioccipitale; cso, crista supraoccipitalis; exo, os exoccipitale; f, os frontale; j, os jugale ; mx, os maxillare; q, os quadratum; qj, os quadratojugale; p, os parietale; pdp, processus descendens ossi parietale (dorsal part); pf, os praefrontale; pl, os palatinum ; pmx, os praemaxillare ; po, os postorbitale; ppe, processus pterigoideus externus (vertical plate); s, os squamosum; v, os vomer.
Source publication
This study examines the anatomy and histology of the feeding apparatus of two closely related turtle species, the Malayan box turtle (Cuora amboinensis) and the yellow-margined box turtle (Cuora flavomarginata). The focus was on the kinematic patterns of terrestrial and aquatic feeding. Feeding patterns were analyzed by high-speed cinematography. B...
Contexts in source publication
Context 1
... feeding modes were investigated only in C. amboinensis. Six kinematic variables are represented in Table 3. The turtles approached the food item slowly. When the tip of the upper jaw was at 1.3270.34 cm from the fish, the forward locomotion stopped. The body and the head remained static. The prey capture started with a hyoid protraction and lifting, followed by neck extension (Fig. 9A and B). Jaw opening started during the fast neck extension. Upon reaching peak gape, the jaws were moved over the prey. No division into different gape phases was detected during mouth opening. The extension of the neck continued after the peak gape was reached. The gape remained for a maximum of 0.01270.002 s and, during this phase, the hyoid retraction started. Hyoid retraction lasted 0.04270.006 s. The peak ventral hyoid depression was reached during the jaw closing phase. Jaw closing phase was very short: 0.03370.004 s. During ingestion, the prey remained static. No inertial suction effect was detected ( Fig. 9B2 and B3). The first contact with the prey always occurred at the jaws. Due to the impulse of the fast forward strike of the head, the grasped food item moved in the same direction. Ingestion ended with head retraction. The gape could not be completely closed because the prey was not entirely in the oral cavity. The water volume taken up during prey capture was expelled by protracting the hyoid complex to its resting ...
Context 2
... schematic illustration of the most important jaw and hyoid muscles is shown in Fig. 3A and B. The m. adductor mandibulae externus fills the whole upper temporal fossa. The mm. add. mand. ext. pars superficialis and pars profunda are strongly developed in C. amboinensis (Fig. 2D) and relatively small in C. flavomarginata (Fig. 2B). The external tendon system is well-developed and has a myovector-chang- ing function (see Bramble, 1974;Jordanskii, 1990). C. amboinensis possesses a large transiliens bulge (3.470.3 mm in diameter) within the external adductor tendon. The m. adductor mandibulae posterior has no insertion on the temporal bone, and we were unable to externus pars superficialis; bo, os basioccipitale; cso, crista supraoccipitalis; exo, os exoccipitale; f, os frontale; j, os jugale ; mx, os maxillare; q, os quadratum; qj, os quadratojugale; p, os parietale; pdp, processus descendens ossi parietale (dorsal part); pf, os praefrontale; pl, os palatinum ; pmx, os praemaxillare ; po, os postorbitale; ppe, processus pterigoideus externus (vertical plate); s, os squamosum; v, os vomer. detect a margin splitting that muscle into caudal and rostral portions (see Schumacher, 1956). No clear morphological separation of the m. add. mand. internus into a pars pseudotemporalis and pars pterygoideus was ...
Context 3
... schematic illustration of the most important jaw and hyoid muscles is shown in Fig. 3A and B. The m. adductor mandibulae externus fills the whole upper temporal fossa. The mm. add. mand. ext. pars superficialis and pars profunda are strongly developed in C. amboinensis (Fig. 2D) and relatively small in C. flavomarginata (Fig. 2B). The external tendon system is well-developed and has a myovector-chang- ing function (see Bramble, 1974;Jordanskii, 1990). C. amboinensis possesses a large transiliens bulge (3.470.3 mm in diameter) within the external adductor tendon. The m. adductor mandibulae posterior has no insertion on the temporal bone, and we were unable to externus pars superficialis; bo, os basioccipitale; cso, crista supraoccipitalis; exo, os exoccipitale; f, os frontale; j, os jugale ; mx, os maxillare; q, os quadratum; qj, os quadratojugale; p, os parietale; pdp, processus descendens ossi parietale (dorsal part); pf, os praefrontale; pl, os palatinum ; pmx, os praemaxillare ; po, os postorbitale; ppe, processus pterigoideus externus (vertical plate); s, os squamosum; v, os vomer. detect a margin splitting that muscle into caudal and rostral portions (see Schumacher, 1956). No clear morphological separation of the m. add. mand. internus into a pars pseudotemporalis and pars pterygoideus was ...
Context 4
... both species the skull is anapsid and akinetic. The temporal roof is ventrally and dorsally open due to emarginations (see Fig. 2). The temporal arch is complete and consists of three elements: os postorbitale, os jugale and os quadratojugale. An os quadratojugale was also found in C. flavomarginata (in contrast to Wermuth andMertens, 1961 andErnst andBarbour, 1989). No direct connection between the jugal and the quadratojugal bones was detected. The supraoccipital bone bears a crista supraoccipitalis. The dorsal ridge is straight and extends behind the foramen magnum occipitale in C. amboinensis (Fig. 2C). In C. flavomarginata, the crista supraoccipitalis is shorter, convex and has fenestrations ( Fig. 2A). The jaw articulation, as typical of the Cryptodira, allows no lateral mandible movements. The trochlear process is formed only by the quadrate bones. The palate is flat in C. amboinensis but concave in C. flavomarginata (see also Heiss et al., 2008). The palatines are bright bony plates, they are robust in the Malayan box turtle but thin and transparent in C. ...
Context 5
... both species the skull is anapsid and akinetic. The temporal roof is ventrally and dorsally open due to emarginations (see Fig. 2). The temporal arch is complete and consists of three elements: os postorbitale, os jugale and os quadratojugale. An os quadratojugale was also found in C. flavomarginata (in contrast to Wermuth andMertens, 1961 andErnst andBarbour, 1989). No direct connection between the jugal and the quadratojugal bones was detected. The supraoccipital bone bears a crista supraoccipitalis. The dorsal ridge is straight and extends behind the foramen magnum occipitale in C. amboinensis (Fig. 2C). In C. flavomarginata, the crista supraoccipitalis is shorter, convex and has fenestrations ( Fig. 2A). The jaw articulation, as typical of the Cryptodira, allows no lateral mandible movements. The trochlear process is formed only by the quadrate bones. The palate is flat in C. amboinensis but concave in C. flavomarginata (see also Heiss et al., 2008). The palatines are bright bony plates, they are robust in the Malayan box turtle but thin and transparent in C. ...
Context 6
... both species the skull is anapsid and akinetic. The temporal roof is ventrally and dorsally open due to emarginations (see Fig. 2). The temporal arch is complete and consists of three elements: os postorbitale, os jugale and os quadratojugale. An os quadratojugale was also found in C. flavomarginata (in contrast to Wermuth andMertens, 1961 andErnst andBarbour, 1989). No direct connection between the jugal and the quadratojugal bones was detected. The supraoccipital bone bears a crista supraoccipitalis. The dorsal ridge is straight and extends behind the foramen magnum occipitale in C. amboinensis (Fig. 2C). In C. flavomarginata, the crista supraoccipitalis is shorter, convex and has fenestrations ( Fig. 2A). The jaw articulation, as typical of the Cryptodira, allows no lateral mandible movements. The trochlear process is formed only by the quadrate bones. The palate is flat in C. amboinensis but concave in C. flavomarginata (see also Heiss et al., 2008). The palatines are bright bony plates, they are robust in the Malayan box turtle but thin and transparent in C. ...
Citations
... Most aquatic tetrapods combine suction feeding with ''ram feeding'' (fast approach to the prey plus jaw prehension; Bramble and Wake, 1985;Bels et al., 1998;Schwenk, 2000a;Lemell et al., 2002;Schwenk and Rubega, 2005). Fully (nonmarine) aquatic turtles have a strongly reduced tongue with a flat surface (Winokur, 1988;Iwasaki, 1992;Iwasaki et al., , 1996Beisser et al., 1995Beisser et al., , 1998Beisser et al., , 2001Beisser et al., , 2004 to save space that can be used for volumetric expansion during underwater suction feeding Lemell and Weisgram, 1997;Lemell et al., 2000Lemell et al., , 2002Natchev et al., 2007). They lack multicellular glands on the tongue and on the palate: an extensive, sticky or lubricating mucus film is unnecessary under water. ...
... We analyzed terrestrial feeding events to demonstrate the possible correlation between TB-distribution and the prehension mode in our semiaquatic turtle. C. amboinensis uses jaw prehension for food uptake on land (Fig. 7A,B) and a similar approach under water (Natchev et al., 2007). The first contact to the food item occurs usually in the tip of the jaws. ...
Scanning Electron Microscopy (SEM) revealed that the palate of Cuora amboinensis has a flat surface with keratinized and non-keratinized regions. Keratinization is reflected in disc-shaped keratinized dead cells with rough microplicae on the surface, and is concentrated close to the rhamphotheca. The surface of the non-keratinized hexagonal epithelial cells is dotted with microvilli and sometimes with cilia. Taste buds are present both in lightly keratinized and non-keratinized regions and exhibit a crater-like shape. Light microscopy shows the different tissue layers of the oral mucosa and the different epithelial structures. In keratinized regions, keratinocytes mature from basal to superficial, where they build up keratin layers of varying thickness. In non-keratinized regions, the epithelial cells are arranged in a stratified fashion, and cuboidal to cylindric cells form a superficial layer. Goblet cells appear to be diffusely distributed, but are often organized in goblet cell fields which can be folded into crypts. Taste buds consist of slender epithelial cells, exhibit the typical barrel-like shape and are specially concentrated in the anterior, praechoanal palate. This anterior concentration of taste buds is shown by kinematographic analysis to correlate with the food prehension mode in Cuora amboinensis. The lamina propria of the palatal mucosa consists of loose connective tissue with inflammatory cells between capillaries. All these structures of the oral mucosa act as a functional entity and help determine how successfully an organism adapts ecologically to the environment.
