Individual-level diet variation in four species of Brazilian frogs

Many natural populations exploiting a wide range of resources are actually composed of relatively specialized individuals. This interindividual variation is thought to be a consequence of the invasion of `empty` niches in depauperate communities, generally in temperate regions. If individual niches are constrained by functional trade-offs, the expansion of the population niche is only achieved by an increase in interindividual variation, consistent with the `niche variation hypothesis`. According to this hypothesis, we should not expect interindividual variation in species belonging to highly diverse, packed communities. In the present study, we measured the degree of interindividual diet variation in four species of frogs of the highly diverse Brazilian Cerrado, using both gut contents and delta(13)C stable isotopes. We found evidence of significant diet variation in the four species, indicating that this phenomenon is not restricted to depauperate communities in temperate regions. The lack of correlations between the frogs` morphology and diet indicate that trade-offs do not depend on the morphological characters measured here and are probably not biomechanical. The nature of the trade-offs remains unknown, but are likely to be cognitive or physiological. Finally, we found a positive correlation between the population niche width and the degree of diet variation, but a null model showed that this correlation can be generated by individuals sampling randomly from a common set of resources. Therefore, albeit consistent with, our results cannot be taken as evidence in favour of the niche variation hypothesis.

A NOVEL EPIPHYTIC CYANOBACTERIAL SPECIES FROM THE GENUS BRASILONEMA CAUSING DAMAGE TO EUCALYPTUS LEAVES

A cyanobacterial mat colonizing the leaves of Eucalyptus grandis was determined to be responsible for serious damage affecting the growth and development of whole plants under the clonal hybrid nursery conditions. The dominant cyanobacterial species was isolated in BG-11 medium lacking a source of combined nitrogen and identified by cell morphology characters and molecular phylogenetic analysis (16S rRNA gene and cpcBA-IGS sequences). The isolated strain represents a novel species of the genus Brasilonema and is designated Brasilonema octagenarum strain UFV-E1. Thin sections of E. grandis leaves analyzed by light and electron microscopy showed that the B. octagenarum UFV-E1 filaments penetrate into the leaf mesophyll. The depth of infection and the mechanism by which the cyanobacterium invades leaf tissue were not determined. A major consequence of colonization by this cyanobacterium is a reduction in photosynthesis in the host since the cyanobacterial mats decrease the amount of light incident on leaf surfaces. Moreover, the cyanobacteria also interfere with stomatal gas exchange, decreasing CO2 assimilation. To our knowledge, this is the first report of an epiphytic cyanobacterial species causing damage to E. grandis leaves.

Status of chemical elements in Atlantic Forest tree species near an industrial complex

Environmental quality assessment studies have been conducted with tree species largely distributed in the Atlantic Forest. Leaf and soil samples were collected in the conservation unit Parque Estadual da Serra do Mar (PESM) nearby the industrial complex of Cubatao, Sao Paulo State, Brazil, and analyzed for chemical elements by instrumental neutron activation analysis. Results were compared to background values obtained in the Parque Estadual Carlos Botelho (PECB). The higher As, Fe, Hg and Zn mass fractions in the tree leaves of PESM indicated anthropogenic influence on this conservation unit.

Rare canopy species in communities within the Atlantic Coastal Forest in Rio de Janeiro State, Brazil

Rare species are one of the principal components of the species richness and diversity encountered in Dense Ombrophilous Tropical Forests. This study sought to analyze the rare canopy species within the Atlantic Coastal Forest in Rio de Janeiro State, Brazil. Six different communities were examined: Dense Ombrophilous alluvial Forest; Dense sub-montane Ombrophilous Forest; Dense Montane Ombrophilous in Serra do Mar and Serra da Mantiqueira. In each area the vegetation was sampled within forty 10 x 25 m plots alternately distributed along a linear transect. All trees with DBH (1.3 m above ground level) a parts per thousand yen5 cm were sampled. The canopy was characterized using the allometric relationship between diameter and height, and included all trees with BDH a parts per thousand yen10 cm and height a parts per thousand yen10 m. A total of 64 families, 206 genera, and 542 species were sampled, of which 297 (54.8%) represented rare species (less than one individual per hectare). The percentage of rare species varied from 34 to 50% in each of the different communities sampled. A majority of these rare trees belonged to the Rosidae, and a smaller proportion to the Dilleniidae. It was concluded that there was no apparent pattern to rarity among families, that rarity was probably derived from a number of processes (such as gap formation), and that a great majority of the rare species sampled were consistently rare. This indicates that the restricted geographic distribution and high degree of endemism of many arboreal taxa justifies the conservation of even small fragments of Atlantic Forest.

A new genus for seven Brazilian land planarian species, split off from Notogynaphallia (Platyhelminthes, Tricladida)

Special attention is given to cephalic structures of a species complex within the Notogynaphallia ( Platyhelminthes, Tricladida). Notogynaphallia muelleri is redescribed. The species possesses a cephalic musculo-glandular organ. Its glandular and muscular organization are similar to that previously observed in N. caissara and N. fita and to that herein described for N. abundans, N. ceciliae, N. ernesti, and N. graffi. Based on these unique cephalic specializations, a new genus is proposed for these seven species. Functionally, the musculo-glandular organ may be an adaptation for capturing and holding prey.

A new Peruvian land planarian species of the genus Gigantea (Platyhelminthes, Tricladida, Geoplanidae)

A new species of Geoplaninae land planarian from south Peru, Gigantea urubambensis sp. nov., is described. The most outstanding features of the new species are the very dorsal location of the testes, between the dorsal diagonal and the supra-intestinal parenchymatic muscle layers; a penis papilla projecting from the roof of the male atrium and acentrally traversed by the ejaculatory duct; and the absence of glandular ridges on the penis papilla.

New familial assignments for three species of Neotropical harvestmen based on cladistic analysis (Arachnida: Opiliones: Laniatores)

We herein propose transfer of the two monotypic genera Globibunus (type-species G. rubrofemoratus Roewer, 1912) and Rivetinus (type-species R. minutus Roewer, 1919) to the subfamily Zamorinae (Agoristenidae) and Ramonus (type-species R. conifrons Roewer, 1956), previous placed in Agoristenidae, to the Prostygninae (Cranaidae) based on several characteristics of male genitalia. These transfers are corroborated by a cladistic analysis, which also recovered the three currently recognized agoristenid subfamilies.

A new species and new distribution records of Pickeliana (Opiliones: Laniatores: Stygnidae)

A new species of Pickeliana Mello-Leitao,1932, P. albimaculata sp. nov, is described from Jussari, Bahia, Brazil. It can be easily distinguished from the already described species by the presence of white spots on mesotergal area I and anal opercle. It is similar to P. pickeli Mello-Leitao,1932 by the presence of a large, ventro-apical pointed tubercle on femora III-IV A cladistic analysis was performed adding a new character to the available character matrix, the presence of a large and ventro-apical pointed tubercle on male femur IV According to this analysis, P. albimaculata sp. nov is sister species of P.pickeli.Additionally,we present an identification key and an update on the geographical distribution of species of this genus in northeastern Brazil.

A new species of Brazilian troglobitic harvestman of the genus Iandumoema (Opiliones : Gonyleptidae)

Iandumoema setimapocu sp.n. is described from the cave Lapa do Zu, Coraao de Jesus, Minas Gerais State, Brazil. The new species is closely related to Iandumoema uai Pinto-da-Rocha, 1996 in the subfamily Pachylinae, from which it differs by the following features: Male femur IV straight; the male apophysis on coxa IV directed obliquely backward; eyes depigmented; tubercles on femur IV close to each other, separated by about one diameter; male pedipalpal tibia with ectal setae IiiIi; lack of median setae on ventral plate of penis. Iandumoema is the first exclusively troglobitic genus of Opiliones in Brazil that contains two species.

A new species of land planarian of Gigantea Ogren and Kawakatsu, 1990 (Platyhelminthes, Tricladida, Terricola) from Colombia, with taxonomic remarks on the genus

A new species of land planarian from Colombia, Gigantea maupoi sp. nov., is described herein. The penis papilla of the new species is provided with numerous accessory genital organs, or mgo. These mgo are of a unique morphology, consisting of a very strong barrel-shaped circular muscle coat and an underlying longitudinal one, both derived from the subepithelial musculature of the penis papilla. The central mass of each mgo contains secretions and 8-15 canalicula that open to the male atrium on the central region of the organ. Differences in structures constituting the mgo and details of the muscular systems and of the reproductive organs among the 11 Gigantea species from literature and from type material of G. bistriata (Hyman, 1962), G. chiriquii (Hyman, 1962), and G. sandersoni (Prudhoe, 1949) reexamined here show that the genus is heterogeneous.

Tropical woods: influence of density in hardness parallel and normal to the grain for some Brazilian tropical tree species

The aim of this work is to verify the possibility to correlating specific gravity and wood hardness parallel and perpendicular to the grain. The purpose is to offer one more tool to help in the decision about wood species choice for use in floors and sleepers. To reach this intent, we considered the results of standard tests (NBR 7190:1997, Timber Structures Design, Annex B, Brazilian Association of Technical Standards) to determine hardness parallel and normal to the grain in fourteen tropical high density wood species (over 850 kg/m(3), at 12% moisture content). For each species twelve determinations were made, based on the material obtained at Sao Carlos and its regional wood market. Statistical analysis led to some expressions to describe the cited properties relationships, with a determination coefficient about 0.8.

The recent occurrence, establishment and potential impact of Geophagus proximus (Cichlidae : Perciformes) in the Tiete River reservoirs: an Amazonian fish species introduced in the Parana Basin (Brazil)

The introduction of allochthonous fish species happens constantly in large bodies of freshwater, like as the reservoirs of Parana Basin, located in Brazilian southeast, representing a threat for local biodiversity. The fish species Plagioscion squamosissimus and Cichla ocellaris were introduced from the 1970s in several water bodies of this basin and had successfully established themselves in all six reservoirs located in the middle and lower Tiete River (SP, Brazil), particularly. After six decades from the first recorded species introduction, this hydrographic system remains open to the invasion of further fish species, owing to widespread fish-farming activity and by the channels opened between this system and other reservoirs and river basin. This study was an effort to confirm the Geophagus proximus occurrence in the six Tiete River reservoirs, verifying the actual introduction status and analyzing its potential environmental impacts on local species by the analysis of the population structure (abundance, body dimensions and feeding habits). By the results, this species was confirmed in the Ibitinga, Nova Avanhandava and Tres Irmaos reservoirs. The abundance and feeding analysis shows, respectively, it is successfully established in the Tres Irmaos reservoir with the same feeding habitats of local species, such as Geophagus brasiliensis. It was further shown to be very likely that G. proximus would spread throughout the reservoir system of the middle and lower Tiete River, in the manner of P. squamosissimus and C. ocellaris, and the competition pressure for food resources between G. proximus and the local species which represents a potential environmental impact system. These scientific evidences fortifies the knowledge basin for the implantation of a fish management system, to control and reduce the abundance of the invader and to prevent its becoming established in all the Tiete River Basin, avoiding the disastrous consequences for the native species of Parana River Basin.

Oxidative stress biomarkers of exposure in the blood of cichlid species from a metal-contaminated river

The oxidative stress biomarkers of exposure, such as reduced glutathione (GSH), activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and the levels of lipid peroxidation (LPO), were measured in the blood of three cichlid fish (Oreochromis niloticus, Tilapia rendalli, and Geophagus brasiliensis) taken during two seasons from two sites, unpolluted and polluted by industrial effluents, to evaluate the effectiveness of these biomarkers in assessing the impact of water contamination. The LPO levels in the blood were higher in fish from the metal-contaminated site and the chronic exposure led to significant changes in GPx, CAT, and SOD activities in all three cichlid species. The considerable variation of responses in these cichlids to water contamination evidenced differences in sensitivity to the metal contamination and/or in the potential to respond to it highlighting the importance of using a set of related biomarkers to assess the impact of water contamination. (C) 2007 Elsevier Inc. All rights reserved.

New approaches to underground systems in Brazilian Smilax species (Smilacaceae)

MARTINS, A. R. (Institute of Biology, State University of Campinas - UNICAMP, 13083-970, Campinas, SP, Brazil), N. PUT, (Division of Biology and Education, University of Vechta, 49377 Vechta, Germany), A. N. SOARES, A.B BOMB, and B. APPEZZATO DA GLORIA (Biological Science Department, Escola Superior de Agricultura `Luiz de Queiroz`, University of Sao Paulo, 13418-900, Piracicaba, SP, Brazil). J. Torrey Bot. Soc. 137: 220-235. 2010.-New approaches to underground systems in Brazilian Smilax species (Smilacaceae). Scientific studies show that the watery extract of the thickened underground stem and its adventitious roots of the genus Smilax can act as a therapeutic agent in immunoinflammatory disorders, such as rheumatic arthritis. Brazilians have used this genus of plants in folk medicine, however it is very hard to identify these species, since the morphology of the underground systems is very similar in this group. For better identification of those systems, we studied six species of Smilax L. (S. brasiliensis, S. campestris, S. cissoides, S. goyazana, S. oblongifolia and S. rufescens), collected in different regions of Brazil with different physiognomies and soil characteristics. The main purpose is to describe the morpho-anatomy of the underground systems and to analyze if their structure depends on environmental conditions. The underground stem (rhizophore) is of brown color and it is knotty, massive, slender (S. rufescens) or tuberous (S. brasiliensis, S. campestris, S. cissoides, S. goyazana and S. oblongifolia). The tuberization is a result of primary thickened meristem (PTM) activity. The color and thickness of the adventitious roots change during development because the epidermis and outer cortex are disposed of, so the inner cortex becomes the new covering tissue with lignified and dark color cells. There are differences in starch grain shapes in mature roots. The chemical attributes of the soil are very similar in all studied environments and, even when soil characteristics varied, all the species` underground system was distributed close to the soil surface (10 to 15 cm deep). The species exhibited clonal growth hence their underground system functions as storage structures and the axillary buds can sprout into new stems. Only Smilax rufescens, collected in sandy soil of Restinga, has vegetative dispersal due to the runners.

Chautemsia calcicola: A new genus and species of Gloxinieae (Gesneriaceae) from Minas Gerais,.Brazil

A new species of Gesneriaceae discovered in remnants of deciduous forests on limestone outcrops in Minas Gerais, Brazil, is described and compared with morphologically related taxa. This plant presents the diagnostic features of the tribe Gloxinieae, but a unique combination of morphological traits distinguishes this taxon from previously described genera. Its phylogenetic position was inferred based on analyzing DNA sequences variation of five loci: the rpl1 intron, rps16 intron, trnL-F intron-spacer, a portion of the plastid-expressed glutamine synthetase gene (ncpGS) and the ribosomal DNA internal transcribed spacer (ITS). Molecular phylogenetic analyses confirm the position of this new species in the Gloxinieae, as a sister lineage of a clade including the Brazilian genera Mandirola and Goyazia. However, tests using topological constraints do not reject the alternative relationship that places this taxon with Gloxiniopsis in a monophyletic group. To accomodate this species in the current generic circumscription of gloxinieae, the new genus chautemsia A.O. Araujo V.C. Souza is created.