Filling gaps and a new state record of Xenopholis scalaris (Wucherer, 1861) (Serpentes: Dipsadidae)

Abstract

Abstract:We present the first record of the Dipsadidae snakes Xenopholis scalaris for the state of Rio de Janeiro and a general distribution map for this species. This record for the Brazilian Atlantic Forest expands the known geographical distribution of X. scalaris and reveals that its populations might not be isolated or disjunctive, but rather rare in this biome. We also provide some recommendations for future conservation of X. scalaris.

Taxonomic revision of the genus Xenopholis Peters, 1869 (Serpentes: Dipsadidae): Integrating morphology with ecological niche

“…(10) hemipenial body ornamented with lateral spines and dispersed papillae (vs. hemipenial body ornamented with hooked spines and longitudinal plicae in X. scalaris, and hemipenial body ornamented with hooked spines in X. undulatus); (11) iris brown (vs. pupil red in X. scalaris); (12) neural spine of vertebrae with a narrow septum perpendicular to the longitudinal axis of body (vs. septum absent in X. scalaris); (13) vomerian process of premaxillae overlapping vomers (vs. contacting anteromedial portion of vomers in X. scalaris); (14) nasal process present (vs. absent in X. undulatus); (15) pair of nasals smaller than frontals (vs. about the same length of frontals in X. scalaris); (16) dorsal crests of parietal contacting each other (vs. not contacting each other in X. scalaris and X. undulatus); (17) contact between frontals and postorbitals present (vs. no contact in X. scalaris); (18) contact between supratemporals and supraoccipital present (vs. absent in X. undulatus); (19) ten palatine teeth (vs. seven in X. scalaris); (20) 23 teeth in the pterygoids (vs. 28 in X. scalaris and 14 X. undulatus).…”

“…It includes small to moderate-sized snakes (300-450 mm), with cryptozoic lifestyle (i.e., underneath soil surface and high humidity habitats) [3][4][5][6], feeding primarily on anurans [4,[7][8][9], but occasionally also lizards [6]. Members of the genus are widely distributed in the cis-Andean Neotropics: Xenopholis scalaris ranges from the cis-Andean portion of South America along the ombrophilous forests of Colombia, Guianas, Ecuador, Peru, Bolivia and Brazil, with disjunct populations along the Atlantic Forest [4,[7][8][9][10][11][12][13][14][15][16]; Xenopholis undulatus is distributed in Paraguay and also in open areas of the Brazilian Shield, from Maranhão south to Paraná [13]; and Xenopholis werdingorum occurs at the Chiquitanos forests of Bolivia and within the Pantanal wetlands [5,13,17,18]. Due to their small body sizes and secretive lifestyle, species of this genus are rarely found [3,7], resulting in poor representation in herpetological collections and scarce literature regarding their biology and morphological variation.…”

“…X. werdingorum); (5) subcaudal scales 28-45 in males, 27-42 females (vs. 36-55 in males of X. undulatus and 46-54 of X. werdingorum; and 33-60 in females of X. undulatus and 38-48 of X. werdingorum); (6) postocular scale single (vs. two postoculars in X. undulatus and X. werdingorum); (7) hemipenis unilobed with bifurcated sulcus spermaticus (vs. unilobed usually with single sulcus spermaticus in X. undulatus and bilobed organ in X. werdingorum);(8) hemipenis strongly capitulated on the sulcate side (vs. slightly capitulated in X. undulatus and not capitulated in X. werdingorum); (9) capitulum ornamented with spinulate calyces (vs. papillate on distal portion of capitulum in X. undulatus and entirely papillate in X. werdingorum); (10) hemipenial body ornamented with hooked spines and longitudinal plicae (vs. hemipenial body ornamented with hooked spines and dispersed papillae in X. undulatus and X. werdingorum); (11) pupil red (vs. brown in X. undulatus and X. werdingorum); (12) neural spine of vertebrae without septum perpendicular to longitudinal axis of body (vs. presence of a narrow longitudinal septum in X. undulatus and X. werdingorum); (13) vomerian process of premaxillae contacting mesolateral portions of vomers (vs. overlapping vomers in X. undulatus and X. werdingorum);(14) nasal process present (vs. absent in X. undulatus);(15) pair of nasals about the same length of frontals (vs. smaller than frontals in X. undulatus and X. werdingorum); (16) dorsal crests of parietal not contacting each other (vs. contacting each other in X.…”

Non-Avian Reptiles of the state of Rio de Janeiro, Brazil: status of knowledge and commented list

“…The first comprehensive inventory on the reptile species of RJ state was published about 15 years ago (Rocha et al, 2004), in which 127 species of reptiles were known to occur in the state (one crocodilian, seven amphisbaenians, nine chelonians, 28 lizards and 82 snakes). A number of subsequent studies have increased the knowledge on reptile composition of RJ by inventorying areas in the state (e.g., Citeli et al, 2016;Rocha et al, 2018;Martins et al, 2019) extending the geographic distribution of some species (e.g., Silveira, 2008;Goyannes-Araújo et al, 2009;Hamdan et al, 2015), describing new taxa (e.g., Fernandes et al, 2010;Prates et al, 2020), and providing new records of non-indigenous species (e.g., Siciliano et al, 2014;Oliveira et al, 2018). The recent advances, along with a number of additional taxonomic adjustments through the years (e.g., Sturaro et al, 2018;Hoogmoed et al, 2019), made the species list of RJ become outdated.…”