Abstract
Detailed descriptions of tongue morphology of members of Squamata that refer to functional implications other than food processing are rare. Herein we focus on the morphology of the dorsal epithelium and internal structure of the tongue of the Leopard Gecko, Eublepharis macularius, emphasizing the foretongue and its relation to fluid uptake. We employ both scanning electron microscopy and serial histology to examine the morphology of the entire tongue, its component regions, and its situation in the oral chamber. We recognize five distinct morphological regions of the dorsal tongue surface, each of which is distinctive both morphologically and histologically. The foretongue bears papillae quite different in structure and spacing from those of all other tongue regions, and these non-glandular structures are involved in gathering and transporting fluid from the environment. Fluid unloaded from the foretongue in the region of the vomeronasal sinus is channeled through the network of cuboidal papillae and directed towards a pair of compartments lateral to the tongue in which fluid pools during a drinking bout. This allows the dorsal surface of the mid- and hind-tongue, which are involved in food processing and manipulation, to be largely segregated from the pathway of fluid flow. We relate our findings to descriptions of the tongue of other taxa, and propose functional hypotheses for the observed morphology. This study provides new anatomical information upon which future studies of the functional morphology of the buccal apparatus in the Gekkota can be based.
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Acknowledgments
We thank K. Kardong for discussion, and P. Wise for providing specimens. This research was supported in part by an NSERC Discovery Grant to APR.
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Jamniczky, H.A., Russell, A.P., Johnson, M.K. et al. Morphology and Histology of the Tongue and Oral Chamber of Eublepharis macularius (Squamata: Gekkonidae), with Special Reference to the Foretongue and its Role in Fluid Uptake and Transport. Evol Biol 36, 397–406 (2009). https://doi.org/10.1007/s11692-009-9072-9
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DOI: https://doi.org/10.1007/s11692-009-9072-9