Imantodes

Abstract: The Leptodeirini has been presumed to be a monophyletic assemblage based on albumin immunological data and morphology and consisted of neotropical cat-eyed snakes (Leptodeira), blunt-headed vine snakes (Imantodes), nightsnakes (Eridiphas, Hypsiglena, and Pseudoleptodeira), and the cloud forest snake (Cryophis). In the present study, approximately 1.4 kb of mitochondrial DNA sequence data (from cob and nad4) were collected to test the monophyly of the Leptodeirini. These data were analysed using maximum parsimony, maximum likelihood, and Bayesian methods. None of the results supported the monophyly of the Leptodeirini. There was strong support for a clade containing Imantodes and Leptodeira, and another clade containing the nightsnakes, with the latter placed closer to Cryophis and other dipsadine genera (Sibon, Dipsas, and Atractus). This partial reassessment of the Dipsadinae infers the group to have an ancestral condition of being rear-fanged, mildly venomous, and feeding on ectothermal vertebrates, with a more derived radiation that has lost the rear-fanged, venomous condition and has a diet specialized on invertebrates. A brief discussion on the biogeography of the dipsadines shows the group to be much older (Palaeocene), consistent with earlier views, as opposed to a more recent (Miocene) hypothesis, as has been recently suggested. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 92, 483–500.

Abstract: Cat-eyed snakes (Leptodeira) were thought to be closely related to nightsnakes (Hypsiglena and Pseudoleptodeira) based on morphology and immunological data, which allied these genera with blunt-headed vine snakes (Imantodes) and the Cloud Forest Snake (Cryophis hallbergi ). We collected sequence data from six protein-encoding nuclear loci (SLC30A1, ZEB2, FSHR, NTF3, DNAH3, and PNN; 4149 bp) and additional mtDNA data (nad5; 955 bp) added to published cob and nad4 (total 2387 bp mtDNA) from these and other rear-fanged, mildly venomous snakes that prey on vertebrates (frogs and lizards) and from several other dipsadine genera (Dipsas, Sibon, and Atractus) that prey on invertebrates (goo-eaters). We analyzed relationships using concatenation and a coalescent species-tree method. When analyzed separately, using either concatenation or coalescent methods, nuclear data support a different overall topology from the mtDNA data. Like the mtDNA data, the nuclear data support the Leptodeira + Imantodes relat...

Abstract: Aspects of the behavioral ecology of Imantodes cenchoa, I. gemmistratus and /. lentiferus were studied in large glass enclosures and in a greenhouse. Imantodes is crepuscular and nocturnal and 90% of all daylight hours were spent coiled in bromeliads. Emergence from bromeliads can be divided into three stages. Shifting and rearranging of coils and head emergence occurred between 4-0 foot candles (ft-c) in /. cenchoa and between 19-1 ft-c in /. gemmistratus. Emergence of the head and neck outside of the bromeliad occurred between 4-1 ft-c and 14-1 ft-c in /. cenchoa and /. gemmistratus, respectively. Complete emergence occurred between 1-0 ft-c in /. cenchoa and between 3-0 ft-c in /. gemmistratus. Individuals of Imantodes are morphologically adapted to arboreal living and have SVL-weight relationships that allow movement on the distal ends of branches and the bridging of wide gaps between arboreal perches. At night /. cenchoa and /. gemmistratus foraged for ' food and I. cenchoa fed on sleeping r -anoles. All species drank water beaded on their own bodies and I. gemmistratus frequently entered pools of water. There is a paucityof information on the behavior and ecology of Neotropical snakes. Scattered accounts deal chiefly with macrohabitat, food, and aspects of reproduction and behavior that were observed fortuitously. The main reasons for the lack of information _ are that snakes in Neotropical lowland habitats are secretive and/or exist at low population densities; a researcher might search for months without finding two individuals of the same species. We alleviated these problems by bringing three species of the Neotropical colubrid genus Imantodes into the laboratory to study aspects of their behavior under semi-natural conditions. MATERIALS AND METHODS Ten specimens of Imantodes cenchoa from Honduras and Costa Rica, FIGURE 1. A portion of the greenhouse where Imantodes six I. gemmistratus from Mexico and was studied.