JOSEPH R. MENDELSON IIIDANIEL G. MULCAHYTYLER S. WILLIAMSJACK W. SITES...
34页
查看更多>>摘要：We combine mitochondrial and nuclear DNA sequence data with non-molecular (morphological and natural history) data to conduct phylogenetic analyses and generate an evolutionary hypothesis for the relationships among nearly every species of Mesoamerican bufonid in the genus Incilius. We collected a total of 5,898 aligned base-pairs (bp) of sequence data from mitochondrial (mtDNA: 12S-16S, cyt b, ND2-C01, including tRNAsTRP~TYR and the origin of light strand replication; total 4,317 bp) and nuclear (CXCR4 and RAG1; total 1,581 bp) loci from 52 individual toads representing 37 species. For the non-molecular data, we collected 44 characters from 29 species. We also include Crepidophryne, a genus that has not previously been included in molecular analyses. We present results of parsimony and Bayesian analyses for these data separately and combined. Relationships based on the non-molecular data were poorly supported and did not resolve a monophyletic Incilius (Rhinella marina was nested within). Our molecular data provide significant support to most of the relationships. Our combined analyses demonstrate that inclusion of a considerably smaller dataset (44 vs. 5,898 characters) of non-molecular characters can provide significant support where the molecular relationships were lacking support. Our combined results indicate that Crepidophryne is nested within Incilius; therefore, we place the former in the synonymy of the latter taxon. Our study provides the most comprehensive evolutionary framework for Mesoamerican bufonids (Incilius), which we use as a starting point to invoke discussion on the evolution of their unique natural history traits.
查看更多>>摘要：The Baja California rock squirrel (Otospermophilus atricapillus Bryant) is endemic to the Baja California Peninsula, Mexico and known from only five localities. O. atricapillus is considered as the sister species of O. beecheyi (Richardson) and both have been considered different species mainly by its colorations. In an attempt to better understand the relationship within O. atricapillus and with its sister species O. beecheyi, we used genetic information gathered from O. atricapillus, aiming to investigate the phylogenetic and phylogeography of O. atricapillus - O. beecheyi. We analyzed two sets of mitochondrial cytochrome b gene (Cyt b) data: One 800 (bp) fragments of 118 individuals and a second one of 1140 (bp) for the 32 haplotypes found. Our own hypothesis is that specific characteristics used to distinguish O. artricapillus from O. beecheyi are at the same level than the differences among the recognized subspecies of O beecheyi. Under that condition, a genetic analysis will show that O. atricapillus are within the genetic variation of O. beecheyi, and the current diagnostic characters of O. atricapillus could be considered only at subspecific level. The analysis of molecular variance revealed that O. atricapillus is not significantly different from O. beecheyi, and that, apart from highland populations in the Sierra Nevada, the sampled populations of O. beecheyi and O. atricapillus are not significantly different among all of them.
查看更多>>摘要：Leiopathes montana, a new species previously reported as L. glaberrima (Esper), is described from the plateau of the Great Meteor seamount (North Atlantic) at depth 300-335 m. The new species can be easily distinguished from all other species of the genus by very thin at tips, slightly bended terminal branchlets 0.15-0.2 mm in diameter above the base, rather long in comparison to the size of the colony, small compressed triangular spines 0.02-0.03 mm long and 0.22-0.5 mm apart, and small densely-setpolyps (6-9 per centimeter). Eight species assigned to the genus Leiopathes represent two distinct groups: (1) sparsely branched forms with longer terminal branchlets (L. glaberrima, L. valdiviae, L. acanthophora, L. bullosa, L. montana), and (2) forms with sinusoidal stem and branches, and very short branchlets forming flabellate fronds (L. expansa, L. grimaldii, L. secunda). The largest in size syntype of L. grimaldii Roule, 1902 collected off the Azores is proposed here as the lectotype, since it isthe only full grown and complete specimen and also the only specimen illustrated and described in detail by Roule.
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