Estudo sistemático de dendrophidion dendrophis (Schlegel, 1837) e chironius scurrulus (Wagler, 1824) do Pará, Brasil (serpentes: colubridae: colubrinae: colubrini )

Abstract

Chironius scurrulus (Schlegel, 1837) and Dendrophidion dendrophis (Wagler, 1830) are Neotropical snakes widely distributed in northern South America, having great systematic complication and lack of morpho-anatomical knowledge. The present work aims at the taxonomic recharacterization of the species in question, thus contributing to the knowledge of the Neotropical ofidiofauna. In C. scurrulus, the sublobular constriction of the hemipennis is confirmed. After analyzing all specimens of D. dendrophis from the MPEG herpetological collection (n= 75), we found that there were two series, one containing the number of subcaudal scales in agreement with the literature - series A - and another in which this number is higher - series B. With this, hemipennis (series =, n= 3 and series B, n= 3) and syncraniums (series A, n= 4 and series B, n= 3) of the two series were prepared for comparison. No differences were noted between the syncrania from series A and series B with respect to osteological accidents. The analysis of the prepared hemipennis also showed no difference, that is, both series have the same ornamentation, with the bifurcated groove remaining discretely at the apex of the organ. In relation to the two series, it was concluded that both belong to the same group, for not presenting differences in their internal structures; however, the number of subcaudal scales should be changed to between 127 (min.) and 208 (max.). Observations on the hemipennis indicated the absence of synapomorphy in the subfamily Colubrinae (asymmetrical hemipennis; simple and asymmetrical spermatic groove, running along the right lobe when bilobed), thus the need for reallocation of the species to another group.