Taxonomic studies on marine triclads (Turbellaria,Tricladida, Maricola)

The genus Procerodes forms a heterogeneous assemblage of taxa. Although it is premature to attempt phylogenetic weighting of the characters, the genus contains three well delimited subgroups, one with a subantarctic, panaustral distribution, one world-wide in distribution, and one occurring principally in the northern hemisphere. Outside of these subgroups, species in this genus are problematic since a number of their features also occurs in other procerodids. All recognized groups exhibit a wide distributional range. Many of the world-wide taxonomic relations lie on the species level and some at the level of genera. Poor dispersal capacity of extant species of Procerodes suggests that the biogeographic patterns may be very old.     

Phylogenetic relationships of the genus Dugesia (Platyhelminthes, Tricladida, Paludicola)

A phylogenetic analysis was performed on the genera and subgenera within the freshwater triclad family Dugesiidae, based on 19 terminal taxa and 17 morphological characters. The phylogenetic tree proposed has length of 27 steps and consistency index of 0.66. This phylogenetic hypothesis implies that the current genus Dugesia is paraphyletic and that its subgenera Girardia, Schmidiea and Dugesia S.S. should be elevated to the rank of genus. The genera Cura, Spathula and Neppia are presumed monophyletic by default because the database was unable to provide autapomorphies for any of these genera. The genera Dugesia S.S. and Neppia share sistergroup relationship. Several characters are discussed which were previously considered to be of phylogenetic importance but were not included in the present analysis. It is emphasized that sensory organs form potentially useful set of phylogenetic characters for the Dugesiidae.     

The genome sequence of the gram-positive sugarcane pathogen Leifsonia xyli subsp. xyli

The genome sequence of Leifsonia xyli subsp. xyli, which causes ratoon stunting disease and affects sugarcane worldwide, was determined. The single circular chromosome of Leifsonia xyli subsp. xyli CTCB07 was 2.6 Mb in length with a GC content of 68% and 2,044 predicted open reading frames. The analysis also revealed 307 predicted pseudogenes, which is more than any bacterial plant pathogen sequenced to date. Many of these pseudogenes, if functional, would likely be involved in the degradation of plant heteropolysaccharides, uptake of free sugars, and synthesis of amino acids. Although L. xyli subsp. xyli has only been identified colonizing the xylem vessels of sugarcane, the numbers of predicted regulatory genes and sugar transporters are similar to those in free-living organisms. Some of the predicted pathogenicity genes appear to have been acquired by lateral transfer and include genes for cellulase, pectinase, wilt-inducing protein, lysozyme, and desaturase. The presence of the latter may contribute to stunting, since it is likely involved in the synthesis of abscisic acid, a hormone that arrests growth. Our findings are consistent with the nutritionally fastidious behavior exhibited by L. xyli subsp. xyli and suggest an ongoing adaptation to the restricted ecological niche it inhabits.     

Geographic patterns in the distribution of Palearctic songbirds

A database was created of digitized equal area distribution maps of 3,036 phylogenetic species of Palearctic songbirds. Biogeographic patterns are reported for two data sets: (1) including all passeriform bird species reported as breeding within the boundaries of our study map, (2) passeriform species restricted in their distribution to our study region, thus excluding the partly extra-limital taxa. With respect to the data set excluding partly extra-limital taxa, the average range size is 238 grid cells (grid cell area: 4,062 km²). Analysis of the geographic distribution of species richness for the full data set showed several hotspot regions, mostly located in mountainous areas. The index of range-size rarity identified similar hotspot regions as that for species richness, albeit that the range-size rarity de-emphasized the central Siberian hotspot. Range-size rarity hotspots that are not evident on the measure of species richness concern a great number of islands. Much more prominent on the index of range-size rarity are the Atlas Mountains of northern Africa, the Jabal al Akhdar region in NE Libya, and the eastern border of the Mediterranean. Restricting the analysis of geographic variation to the 25% of the species with smallest ranges resulted in a greatly simplified pattern of hotspots. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Parasitism of Hylodes phyllodes (Anura: Cycloramphidae) by Hannemania sp (Acari: Trombicuudae) in an area of Atlantic Forest, Ilha Grande, southeastern Brazil

We studied some parameters of the parasitism by the mite Hannemonia sp. on the endemic frog Hylodes phyllodes in the Atlantic Forest of Ilha Grande (Rio de Janeiro State, Brazil). Prevalence, mean abundance, mean intensity and total intensity of infestation, body regions infected, and host sexual differences in parasitism rate of the larvae of Hannemania sp. on individuals of H. phyllodes were assessed. Prevalence was 86.5% (N = 37; total of 1,745 larvae of Hannemania sp) for male hosts and 91.7% (N = 12; total of 330 larvae) for female hosts, with no significant difference between the sexes. Overall prevalence of Hannemania sp. on H. phyllodes was 87.7%. Mean intensity of infestation in males (54.5 +/- 42.5; range 1-173 larvae) was higher than in females (29.9 +/- 47.6; range 1-166). We conclude that the rates of intensity, abundance, and prevalence of Hannemania larvae parasitizing Hylodes phyllodes at Ilha Grande were considerably high, suggesting that this species of anuran constitutes a relevant host for this mite species to complete its life-cycle in the area. Differences between males and females in infestation rates probably reflect their differential use of space in the forest.