Pattern recognition in early cranial ontogeny of the common vampire bat, Desmodus Rotundus, (. Geoffroy, 1810) and the lesser bulldog bat Noctilio Albiventris Desmarest, 1818, by x-ray microradiography and phase contrast imaging

PESSÔA, L.M.; ROCHA, H.S.; ESCARLATE TAVARES F.; GILES, C.; C. CUSATIS; HÖNNICKE, M.G.; TIRAO, G.; MAZZARO, I.; LOPES, R.T.

Mikolajki

Congreso; 13th International Bat Research Conference. Museum and Institute of Zoology, Polish Academy of Sciences; 2004

Ontogenetic information has been used to formulate hypotheses of homology through comparative studies of ontogenetic sequence and the analysis of interspecific patters of variability. A possible limitation in this approach is usually imposed by the difficulty in the observation of structures in early stages of development, usually performed on cleared and stained specimens. In this study we examine developmental pattern of cranial characters formation in pre born individuals of vampire bats D. rotundus and lesser bulldog bat N. albiventris. We used microradiography and phase contrast radiography, as a first step to understand how the skull characters appears in the primordial stage of embryology. These techniques of non-destructive testing have been used to obtain images with greater resolution. The sample used in this study was collected in central and eastern Brazil, fixed in formaldehyde, and kept in alcohol 70%. The images show the early stages of development of D. rotundus, including the formation of the forearm and the orbital region as well as the post-anterior axis in the embryo. In a subsequent stage of development several cranial structures can be diagnosed. It was possible to identify an advanced stage of development of the mandible with respect to other cranial structures. The microradiography in N. albiventris also revealed the formation of braincase and rostrum in early pre-born embryos. In the rostral region the nasal bones and mandible can be observed. These techniques can be useful for studying rare collection specimens and in ontogenetic pattern recognition. Microradiography and phase contrast imaging improved quality in the analysis of morphological details and permitted the identification of anatomical landmarks which are useful in comparative studies and are still unknown in both pre born bats species.