Showing papers on "Mantella published in 1996"

A 1,4-Disubstituted Quinolizidine from a Madagascan Mantelline Frog (Mantella)

Abstract: A major alkaloid, 217A, in skin extracts of a mantelline frog (Mantella baroni) was isolated by HPLC and the structure defined by 1H-NMR spectral analysis as (1R,4S,10S)- or (1R,4R,10R)-1-methyl-4-(Z)-(1-pent-2-en-4-ynyl) quinolizidine (1). Four other alkaloids207I (2), 231A (3), 233A (4), and 235E‘ (5)detected in frog skin extracts are proposed to be 1,4-disubstituted quinolizidines based on diagnostic mass and FTIR spectra.

On the origin of the malagasy 2mantelza

Abstract: The species of the genus Mantella have brillant colors and patterns, especially Mantellu aurantiacu, and are active during the day. Due to these characteristics, more than 100 years ago herpetologists classified them together with the South American dart-poison frogs D into the family Dendrobatidae. Recently, toxicologists discovered that the skin of Mantellu contains similar toxins to those found in dendrobatid frogs. Nowadays, the Malagasy poison frogs and the neotropical dart-poison frogs belong to two separate taxa , the Mantellinae and the Dendrobatidae, geographically separated by more than 12 O00 km by reason of the continental drift. FORD (1989) has studied the same phenomenon in Dendrobatidae and Arthroleptidae of Africa. Since behavioral characters are postulated to be important for reconstructing phylogeny, 1 will examine this hypothesis by comparing 52 characters of the Malagasy Mantella with the neotropical Dendrobatidae and the behavior of an outgroup of Hyla with regard to homology criteria. A testable phylogeny is established predominantly based on shared behavioral characters. It implies that both the frog groups Mantella and Dendrobatidae and probably also Arthroleptis, originate from a common ancestor which must have likely lived in Gondwanaland (Afiica) before Madagascar and South America become isolated. KEY-WORDS - Phylogeny, Ethology, Biogeography, Dendrobatid frogs, Mantella RESUME.- Les especes du genre Mantella sont exceptionelles parmi les grenouilles de Madagascar. Ce sont des animaux diurnes a couleur brillantes et attractives, en particulier M. auruntiaca. Ainsi, les herpetologues les ont classe ensemble, il y a plus d' un siecle, avec les (( grenouilles a poison de fleche )> d'Amerique de Sud dans la famille des Dendrobatidae. En plus, les toxicologues ont recemment decouvert que la peau des Mantella contient des toxines similaires a celles trouvees dans les grenouilles dendrobates. Cependant les <( grenouilles a poison de Madagascar )) et les (( grenouilles a poison de fleches B neotropicales sont actuellement classees dans deux taxa differents, le Mantellinae et le Dendrobatidae, qui sont geographiquement separes par plus de 12 O00 suite a la derive des continents. En 1989, FORD avait etudie le meme phenomene sur la Dendrobatidae et 1'Arthroleptidae d' Afrique. Si on considere que les caracteres comportementaux sont des facteurs importants pour reconstruire une phylogenie, une hypothese est tentee en comparant 52 caracteres des Mantella de Madagascar avec ceux des Dendrobatidae neotropicaux et ceux d'un groupe exterieur, le Hyla. L'ensemble etant base sur des criteres d' homologie. En effet, une phylogenie basee sur des caracteres comportementaux communs a ete etablie. Ce qui suggere que, les deux groupes de grenouilles (Mantella et Dendrobatidae) et aussi probablement l'Arthroleptis, proviennent directement d'un ancetre commun qui aurait vecu sur l'ancien continent gondwanien. MOTS-CLES.- Phylogenie, Ethologie, Biogeographie, Grenouilles Dendrobatidae, Mantella