A New Species of the Ornamental Catfish Genus Peckoltia (Siluriformes: Loricariidae) from Rio Xingu Basin, Brazilian Amazon

Peckoltia is one of the 26 genera that constitute the Ancistrini. Although Peckoltia has been reviewed recently, its taxonomic status is not fully resolved and not easily distinguished from Hemiancistrus. Neither Peckoltia nor Hemiancistrus have any recognized synapomorphies supporting their monophyly. In this paper we describe a new species of Ancistrini from Rio Xingu drainage, Par State, Brazil, and assign it to Peckoltia based on its deep body, presence of large odontodes on the cheeks, and lack of carenate plates on the body. The new species can be easily distinguished from all its congeners by its dorsal-fin color pattern (presence of dark thin stripes in the interradial membranes parallel to fin rays that fragment into small spots in larger specimens vs. bands, spots, dots, or membranes with a darker coloration in all other species). Peckoltia feldbergae, new species, differs from all its congeners except P. bachi, P. oligospila, and P. sabaji by having dark brown spots on the entire body (vs. presence of dark transversal bars on the body or a uniform color). Peckoltia feldbergae, new species, can be distinguished from P. oligospila and P. sabaji by a smaller postanal length (28.432.4 of SL vs. 34.338.8 and 35.741.0, respectively). The description of this species is part of an effort to improve our knowledge about the remarkable diversity of rapids-dwelling loricariid catfishes that are greatly threatened by the construction of several large hydroelectric dams in Brazilian Amazon, and to provide a scientific name for a species exploited by the international aquarium fish trade. © 2012 by the American Society of Ichthyologists and Herpetologists

A fluorescence model of the C[SUB]3[/SUB] radical in comets

Theoretical resonance fluorescence calculations are presented of the triatomic C[SUB]3[/SUB] radical and are compared with observations of the C[SUB]3[/SUB] emission in comets Hale-Bopp and de Vico. A theoretical model of the C[SUB]3[/SUB] vibration-rotational structure in the A[SUP]1[/SUP]Pi[SUB]u[/SUB] - X[SUP]1[/SUP]Sigma[SUB]g[/SUB] [SUP]+[/SUP] electronic system is introduced. The model takes into account the detailed structure of the bending mode nu[SUB]2[/SUB] which is responsible for the emission of the 4050 à group. A total of 1959 levels are considered, with 515 levels in the ground state. The main effort is to model high-resolution spectra of the 4050 à emission in comets C/1995 O1 Hale-Bopp and 122P/1995 S1 de Vico. The agreement between observed and theoretical spectra is good for a value of the dipole moment derivative of dmu/dr ~ 2.5 Debye à [SUP]-1[/SUP]. The modeled C[SUB]3[/SUB] emission exhibits a pronounced Swings effect. Based on observations made with William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, and on observations made at the McDonald Observatory, which is operated by the University of Texas at Austin, USA