The primary structure of three hemoglobin chains from the indigo snake (Drymarchon corais erebennus, Serpentes): First evidence for αD chains and two β chain types in snakes

The hemoglobin of the indigo snake (Drymarchon corais erebennus, Colubrinae) consists of two components, HbA and HbD, in the ratio of 1:1. They differ in both their alpha and beta chains. The amino acid sequences of both alpha chains (alpha(A) and alpha(D)) and one beta chain (betaI) were determined. The presence of an alpha(D)chain in a snake hemoglobin is described for the first time. A comparison of all snake beta chain sequences revealed the existence of two paralogous beta chain types in snakes as well, which are designated as betaI and betaII type. For the discussion of the physiological properties of Drymarchon hemoglobin, the sequences were compared with those of the human alpha and beta chains and those of the closely related water snake Liophis miliaris where functional data are available. Among the heme contacts, the substitution alpha(D)58(E7)His-->Gln is unusual but most likely without any effect. The residues responsible for the main part of the Bohr effect are the same as in mammalian hemoglobins. In each of the three globin chains only two residues at positions involved in the alpha1/beta2 interface contacts, most important for the stability and the properties of the hemoglobin molecule, are substituted with regard to human hemoglobin. On the contrary, nine, eleven, and six alpha1/beta1 contact residues are replaced in the alpha(A), alpha(D), betaI chains, respectively

Natural history and distribution of Agalychnis craspedopus (Funkhouser, 1957) (Amphibia: Anura: Hylidae)

Aspects of reproductive behaviour, calls, clutch sizes, and larval morphology are described for Agalychnis craspedopus (Funkhouser, 1957). New distributional records extend the range of this species to southern Amazonian Peru. In most respects reproductive behaviour of A. craspedopus is similar to that of other phyllomedusine frogs. In southern Peru clutches were suspended above water-filled hollow cavities in logs, but in Ecuador tadpoles were found in a pool on the ground with no directlyoverhanging vegetation. Agalychnis craspedopus lays small clutches (mean = 17 eggs) with large eggs. Breeding possibly takes place throughout some years in southern Peru, but this undoubtedly varies depending on rainfall. Some aspects of reproductive biology, and tadpole and adult morphology of A. craspedopus are similar to those of A. calcarifer. Se describe aspectos del comportamiento reproductive, las cantas, las masas de huevos, y la morfología larval de Agalychnis craspedopus (Funkhouser, 1957). También se presenta nuevos registros que extienden el area de dispersión de la especie hasta el sureste del Perú. En la mayoría de aspectos el comportamiento reproductive de A. craspedopus es similar a aquel conocido de otras ranas phyllomedusinas. En el sur del Perú masas de huevos se colocaron arriba de cavidades en troncos lleno de agua, pero en Ecuador renacuajos se hallaron en un charco sin vegetación sobresaliente. Agalychnis craspedopus pone masas pequeñas (por promedio con 17 huevos) de huevos grandes. Possiblemente, la reproducción sucede en todas épocas en el sur del Perú, pero esto varia según la cantidad de lluvia. Algunos aspectos de la biología reproductive y la morfología de los renacuajos y adultos de A. craspedopus son similares a aquellas de A. calcarifer

Intercontinental community convergence of ecology and morphology in desert lizards

Evolutionary ecologists have long debated the extent to which communities in similar environments but different geographic regions exhibit convergence. On the one hand, if species' adaptations and community structure are determined by environmental features, convergence would be expected. However, if historical contingencies have long-lasting effects convergence would be unlikely. Most studies to date have emphasized the differences between communities in similar environments and little quantitative evidence for convergence exists. The application of comparative phylogenetic methods to ecological studies provides an opportunity to further investigate hypotheses of convergence. We compared the evolutionary patterns of structural ecology and morphology of 42 species of iguanian lizards from deserts of Australia and North America. Using a comparative approach, we found that evolutionary convergence of ecology and morphology occurs both in overall, community-wide patterns and in terms of pairs of highly similar intercontinental pairs of species. This result indicates that in these desert lizards, deterministic adaptive evolution shapes community patterns and overrides the historical contingencies unique to particular lineages