Paedomorphosis in two small species of toothed whales (Odontoceti): how and why?

To evaluate and assess the ontogenetic background for paedomorphosis in phocoenids, samples of 144 harbour porpoises, 81 white‐beaked dolphins, and 130 Commerson's dolphins were compared in terms of the development of epiphyseal fusion, cranial suture fusion, and ontogeny of cranial shape. Harbour porpoises and Commerson's dolphins terminated growth and development of all investigated traits sooner than white‐beaked dolphins, leading to lesser degrees of fusion of skeletal elements and less postnatal allometric development. The latter occurred even though shape in the two paedomorphic species developed at twice the rate relative to the size of white‐beaked dolphins. These observations imply that progenetic evolution has occurred convergently in phocoenid and Cephalorhynchus ancestors. The truncated ontogenies allow sexual maturity to be attained earlier and provide a greater reproductive potential. Both species inhabit similar temperate productive habitats and, hence, ecological factors are proposed to have supplied the selection pressures leading to progenesis. Constant prey availability must be a prerequisite for the observed phenomena because frequent food‐intake is necessitated by the limited capacity for energy storage and high heat‐loss entailed by the resulting small body sizes. Progenesis has rarely been proposed in mammal species. This may reflect rarity or that mammalian expressions of progenesis are less obvious. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 278–295.     

Fish diversity and community structure in two small tributaries of the Paraná River,Paraná State,Brazil

In eleven sites on two small tributaries of the Paraná River (North-West Paraná State), 6.8 and 4.0 km in length, 1263 fish specimens of 28 taxons and 14 families were collected using electrofishing. Up to twelve years ago the catchments of the two rivers were covered by tropical jungle; this has now been replaced by pasture and arable fields. Mean diversity indices of Simpson and Shannon indices were close to 0.6, which would indicate that human impact affected fish populations although the river beds have retained their original shape, except cleared of riparian trees. Despite their close location (about 18 km), the two streams differed from each other in their fish faunal composition. The distinctive nature of the fish communities in the two streams was a result of: conductivity, pH, also hiding places, riparian vegetation, submerged macrophytes and depth and width of the rivers.     

Populations and production of fish in two small tributaries of the Paraná River,Paraná, Brazil

Mean biomass (153-1) and production (P) of fish in two small tributaries of the Paraná River (Paraná, Brazil) were 61 kg ha^–1 and 48 kg ha^–1 yr^–1 in the Caracu River and 29 kg ha^–1 and 26 kg ha^–1 yr^–1 in the Agua do Rancho River, respectively. Matrix correlation analysis revealed high positive correlations of both 153-2 and P to maximum depth and hiding places and, at a lower level of significance, to mean depth, pH and oxygen level. Lower 153-3 and P values were found in the Agua do Rancho River, whose valley has retained a more natural character, rich canopy and scarcity of macrophytes, but also lower conductivity and nitrogen and phosphate levels than those in the Caracu River.Address for correspondence     

The reproductive strategy of Leporinus friderici (Characiformes, Anostomidae) in the Paraná River basin: the effect of reservoirs

The reproductive strategy of a species depends upon the interaction between intrinsic and extrinsic factors. Examining the population of Leporinus friderici in two reservoirs of the Upper Paraná River basin in reference to first gonadal maturation and breeding season and sites, the present investigation tested whether the environment formed by damming promoted spatial and temporal changes in the reproductive strategy of this species. Analyses of sex ratios showed that females significantly predominated in Itaipu, while in Corumbá the sexes were about equal with a slight predominance of males. Size-associated sexual dimorphism was observed, that is females dominated the longer length categories, and males the shorter. The minimum size at which L. friderici initiated reproduction varied from year to year, and was larger in the periods soon after formation of both reservoirs. In Itaipu, stabilization between the maximum and minimum lengths at first maturation was also noted after year 6 following closure and continuing until year 15. In general, the breeding season lasted from October through April, although cyclic changes in the duration and intensity of this season were evident. Young individuals predominated during the entire study period in Corumbá. The formation of Itaipu Reservoir had a greater effect on the reproduction of L. friderici, where a gradual adaptation of the reproductive strategy of this species may possibly have been occurring. It is also possible that some of the characteristics of the Itaipu population will in the future be shown by the Corumbá population. It was concluded that reproductive strategies constitute ecological adaptations that are temporally and spatially altered and are fitted to resource availability and environmental pressure.     

Spatial and Temporal Patterns of Diversity and Distribution of the Upper Juruá River Fish Community (Brazilian Amazon)

We studied spatial and temporal patterns in fish species composition and diversity at the upper Juruá River located in the west Brazilian Amazon. We collected with gillnet 822 fishes belonging to 90 species in the main Juruá River, its tributaries and the floodplain lakes during wet and dry seasons. Fish abundance and species richness were greater in the dry season. During that season, fishes may be concentrated due to the low water level, being caught more easily by gillnets. There has been a trend towards a greater fish biomass caught in lakes. This might be associated with a greater environmental stability as lakes may be less subject to large variations in water level. The fish communities differed between the two seasons and between lakes and the lotic environments (main river and tributaries). Fish species from the family Curimatidae were most abundant in the lakes, while Pimelodus spp. and Hypostomus spp. predominated in the main Juruá River. Seasonal variations in fish communities may be related to differences in the migratory behavior among fish species. Such spatial and temporal patterns influencing fish community structure at the Upper Juruá Extractive Reserve must be accounted for in management and conservation strategies.     

Control of eutrophication by silver carp (Hypophthalmichthys molitrix) in the tropical Paranoá Reservoir (Brasília,Brazil): a mesocosm experiment

A mesocosm experiment was conducted to assess the impact of moderate silver carp (Hypophthalmichthys molitrix) biomass (41 g m^–3 or 850 kg ha^–1) on the plankton community and water quality of eutrophic Paranoá Reservoir (Brasília, Brazil). Microzooplankton (copepod nauplii and rotifers <200 m), netphytoplankton (> 20 m), total phytoplankton biomass (expressed as chlorophyll-a) and net primary productivity were significantly reduced by silver carp. Apart from increased nitrogen in the sediment, nutrients and chemical properties of the water were not affected by fish presence. The observed improvements in water quality suggest that stocking silver carp in Paranoá Reservoir to control blue-green algae is a promising biomanipulation practice.     

Onychomycosis in Ceará (Northeast Brazil): epidemiological and laboratory aspects

Knowledge of epidemiological and mycological characteristics of onychomycosis has been noted by many authors as being an important tool for control of these fungal infections. This study seeks to improve knowledge of onychomycosis epidemiology and mycological features. Samples were taken from infected fingernails and toenails of 976 patients undergoing treatment at a respected Dermatology Center in Ceará, Fortaleza, CE, Brazil. Specimens from 512 patients (52%) were positive for onychomycosis. From the culture-positive samples, yeasts of the genus Candida (C. albicans, C. tropicalis, C. krusei, C. parapsilosis) were dominant. The dermatophytes isolated (Trichophyton rubrum, T. tonsurans, T. mentagrophytes var. mentagrophytes) were dominant in 46 patients (12.99%). The mould Fusarium spp. was isolated from 29 patients (8.19%). Yeast of the genus Candida is the main causal factor in onychomycosis in our region. Also, the study showed the importance of performing direct examination and culture in diagnosis of onychomycosis.     

Ecology of mites (Acarina) on small mammals (Eulipotyphla, Rodentia) in Podunajská nížina plain

This study deals with the species distribution and structure of mite communities living in the fur of small mammals. Mesostigmatic mites (Acarina: Mesostigmata) of several small mammal species were studied at several sites of Slovakia situated in the Podunajská ní?na lowland. The aims deal with ecological evaluation of mesostigmatic mites and their small mammal hosts. The research was done from 2005 to 2007. Several small mammal species were caught at 16 sites in the research area. These represent 13 types of biotopes. On the captured small mammals we recorded 3,141 individuals of mesostigmatic mites (7 families and 22 species). The dominance and the diversity of the recorded mites were analysed. Mites being interpreted as the variable one were evaluated by cluster analysis and multifactor analysis (detrended correspondence analysis, principal components analysis, redundancy analysis). Small terrestrial mammals as hosts of mites represent “holders” of environmental factors, in the analysis they are being evaluated as explanatory variable mainly. They transform direct impact of the environment and for that reason the ecological evaluation of mites is specific comparing to other taxonomical and ecological groups of animals.     

Precence of β-Carotene and Xantophylls in two species of the genus Niphargus (Crustacea: Amphipoda)

The presence of carotenoids in the Niphargus tatrensis Wrzesniowski and Niphargus aquilex schellenbergi Karaban has been investigated. In extracts separated by means of column and thin-layer chromatography, the following carotenoids were identified:

1. in Niphargus tatrensis: β-carotene, astaxanthin ester, rubixanthin, celaxanthin and astaxanthin.
2. in Niphargus aquilex schellenbergi: cantha-xanthin, astaxanthin ester, isozeaxanthin (only from Jeker), 4-keto-4′-hydroxy-β-carotene (only from Terzietebronbos), rubixanthin, celaxanthin and astaxanthin.

It was not possible to identifity the sexth fractions.     

AHL-dependent quorum sensing inhibition: synthesis and biological evaluation of α-(N-alkyl-carboxamide)-γ-butyrolactones and α-(N-alkyl-sulfonamide)-γ-butyrolactones

New N-acylhomoserine lactone (AHL) analogues in which the amide function is replaced by a reverse-amide one have been studied as AHL QS modulators. The series of compounds consists of α-(N-alkyl-carboxamide)-γ-butyrolactones, α-(N-alkyl-sulfonamide)-γ-butyrolactones, and 2-(N-alkyl-carboxamide)-cyclopentanones and cyclopentanols. Most active compounds exhibited antagonist activities against LuxR reaching the 30 μM range.     

Habitat selection by two predators in an urban area: The stone marten and red fox in Wrocław (SW Poland)

We analyzed the habitat use of stone martens and red foxes based on incidental observations within the urbanized zone of Wrocław, SW Poland. We compared proportional habitat use at observation sites with randomly selected points and evaluated differences in distance to the water sources and to urban boundaries. Habitat use by both species was different from what we had expected from random points. Stone martens used high-density housing more frequently than red foxes and that expected from random points and avoided open and industrial areas, whereas red foxes used housing estates significantly more often than expected and avoided high-density housing. Both species used the other habitats according to their availability. Stone martens often selected habitats located closer to the city centre, whereas red foxes often selected habitats closer to urban borders than expected. The distribution of red foxes and stone martens is influenced by several factors including the availability of shelter and food, as well as the opportunity to move around undetected. Interspecific competition may also play an important role in habitat selection. Stone martens seem to be better adapted to urbanized areas than red foxes.     

Leishmania (Viannia) braziliensis: epidemiology of canine cutaneous leishmaniasis in the State of Paraná (Brazil)

The present study examines the role that dogs play in the maintenance of the Leishmania cycle in the State of Paraná, Southern Brazil. Dogs were examined in three regions where cutaneous leishmaniasis is endemic or epidemic (R1-Vale da Ribeira; R2-Central region of Paraná State and R3-Northern region). To determine serum prevalence rates ELISA was used. In regions endemic for Trypanosoma cruzi (R1 and R3), serum from dogs seroreactive towards Leishmania antigen was subjected to T. cruzi adsorption in order to eliminate cross-reaction with common antigen epitopes. Concomitantly, dogs with cutaneous lesions were biopsied to isolate and identify parasites using RAPD. Leishmania were classified by the phenetic method using the Jaccard coefficient of similarity, and grouped by Unweighted Pair-Group Method using an Arithmetic Average (UPGMA). A total of 410 dogs were studied. In R1 (Vale da Ribeira) 159 dogs were evaluated of which 10 had anti-Leishmania antibody. In R2 (Central Paraná), 39 animals were examined of which 8 were seropositive. In R3 (the North) 212 dogs were evaluated of which 39 animals were seropositive. Thirteen dogs had cutaneous lesions and the parasites were isolated from a dog with mucocutaneous lesion in R1, two animals with simple skin lesions in R2 and 10 dogs with multiple lesions in R3. The identification of the parasite by molecular methods showed it to be L. (Viannia) braziliensis. Based on this information, the role of domestic dogs in Leishmania infection of cutaneous leishmaniasis in Paraná is discussed.     

Allergenicity of the ornamental urban flora: ecological and aerobiological analyses in C��rdoba (Spain) and Ascoli Piceno (Italy)

Comparative ecological and aerobiological analyses of ornamental urban flora in the cities of Córdoba (Spain) and Ascoli Piceno (Italy) identified a group of plants with allergenic pollen whose behaviour is influenced by a number of factors. The geographical position and the resulting climate of both cities favoured the presence of Mediterranean species. In Córdoba, strongly allergenic evergreens introduced during the Moorish period predominated (Cupressus sempervirens, among others), while in the urban area of Ascoli Piceno, Pinaceae were abundant. In both cities, many species of American origin have been introduced for aesthetic reasons, contributing to an increase in the overall allergenicity of urban greenery. The pollen spectrum differed between the two cities: airborne Oleaceae and Cupressaceae pollen abounded in Córdoba, whilst allergenic pollen from surrounding natural environments (Corylaceae) predominated in Ascoli Piceno. These results pointed to a large number of potentially allergenic species in cities, thus highlighting the importance of greater ecological and aerobiological knowledge of allergenic species of urban ornamental flora. Avoidance of more allergenic species when planning new urban green areas could ensure healthier environments for pollen-allergy sufferers.     

Observations of daytime births in two groups of red-handed howlers (Alouatta belzebul) on an island in the Tucuruí reservoir in eastern Brazilian Amazonia

Births were observed in two free-ranging groups of red-handed howlers (Alouatta belzebul) in eastern Brazilian Amazonia. Both events occurred in the early afternoon, and were relatively rapid and discrete. No other group members approached the females during parturition, nor attempted to interfere with the neonate in any way. Only one of the mothers ingested the placenta. This same female carried the neonate ventrally during the first month of life and then it was carried dorsally. The other infant was carried by its mother in a dorsal position from birth onward. Both infants survived their first month, but subsequently disappeared, in the second and fourth months of life. The precise causes of their death are unknown. In one case, we speculate that the infant's death was due to infestation by botfly larvae.     

Isolation and identification of bovine tuberculosis in a Brazilian herd (São Paulo)

Mycobacterium was verified in animals from a Brazilian dairy herd, a total of 42 samples from 30 cows were submitted to culture and the isolated strains were analyzed by two polymerase chain reaction (PCR), the first specific for species belonging to the Mycobacterium complex (MTBC) and the other for differentiating M. tuberculosis from M. bovis. Twenty seven samples (64.3%) from 18 animals (60%) were positive for mycobacteria by culture, including samples from 15 retrofaryngeal lymphnodes (55.5%), 9 prescapular lymphnodes (33.3%), 2 lungs (7.4%), and 1 liver (3.7%). All isolated colonies were confirmed by PCR to contain MTBC organisms, and were identified as M. bovis by the same methodology.     

New distribution and host records of chalcidoid parasitoids (Hymenoptera: Chalcidoidea) of scale insects (Hemiptera: Coccoidea) in Espírito Santo,Brazil

Three species of chalcidoid parasitoids of scale insects are recorded for the first time in Brazil: Adelencyrtus moderatus, Homalopoda sp., and Diglyphomorpha sp.; and new parasitoid–host associations are recorded between the chalcidoids Encarsia lounsburyi with Hemiberlesia palmae, Encarsia lounsburyi with Melanaspis smilacis, and Diglyphomorpha sp. with Dysmicoccus brevipes.     

Distribution and dynamics of bacterioplankton production in a polymictic tropical lake (Lago Xolotlán,Nicaragua)

From 1988 to 1993 we assessed the variability of bacterioplankton production and biomass in Lake Xolotlán (L. Managua), Nicaragua via [3H]thymidine incorporation into DNA and cell counting. Bacterial production ranged from 3 to 8 μg C l-1 h-1, and since production was equal throughout the water column, areal production was high (≈ 600–1200 mg C m-2 d-1). Bacterial abundance in Lake Managua was extremely high, 7–30 × 109 cells l-1. Thus, specific rates of bacterial production were low. There was a strong correlation between production and number and the specific rate of bacterial production was constant. Comparable measurements of production via [3H]leucine incorporation into proteins indicated that bacteria were experiencing ‘balanced growth’. We conclude that bacterioplankton in Lake Xolotlán had reached its carrying capacity and a significant correlation between bacterial production and concentration of phaeophytin implied that dead or dying algae was the limiting substrate for bacterioplankton. The majority of bacterial number and most of bacterial production (up to 75%) were associated with particles in the >3-μm fraction, probably lysing algal cells to which bacterioplankton were ‘attached’. Grazing on bacterioplankton must be low and bacteria should be a ‘sink’ for organic matter in Lake Xolotlán. This revised version was published online in July 2006 with corrections to the Cover Date.     

Fish populations in the Paraná River: Lentic environments of Diamante and San Pedro Areas (Argentine Republic)

Data on the fish populations of lentic water bodies of the Lower Paraná River in the Diamante and San Pedro areas (33°40–31°55 S, 59°40'–60°40 W), sampled during 1971 are given. Limnological characteristics such as surface area and depth of ponds, water turbidity, and plant cover are included. Differences in fish population size, structure, specific diversity, dominance, and biomass of particular species are established between two areas in a dry season.     

Early effects of forest regeneration with selective and small scale clear-cutting on ground beetles (Coleoptera,Carabidae) in a Norway spruce stand in Southern Bavaria (Höglwald)

This study investigates the early effects of forest regeneration with selective, and small scale clear-cutting, on ground beetle (Coleoptera, Carabidae) community composition in a homogenous, mature spruce forest in Southern Bavaria (Höglwald), Germany. Carabid beetles were sampled with pitfall-, emergence-, and window-traps, from 1999 to 2001 during a pre-treatment year, the year of cutting, and the year after cutting. In the spruce stand we found a relatively low species richness with few dominating species. Selective cutting preserved this carabid assemblage. At the clear-cuts carabid species richness increased in the year of cutting, because of the invasion of small open field species, and the persistence of most forest species. Also, number of individuals increased due to higher numbers caught in the window-traps. The first open habitat species appeared just a few months after felling. However, in the next year the numbers of individuals, especially of forest species,were drastically reduced. Also, the number of species decreased, and was just slightly higher than on the control plot (mature stand). According to the DCA (detrended correspondence analysis) forest interior species had the same habitat preferences as net building spiders (Amaurobiidae, Linyphiidae) and other families of beetles (Staphylinidae, Curculionidae). Several groups of open habitat species responded positively on different patches found in the clear-cut: (1) diversity ofground vegetation, respectively coverage of shrubs, (2) favour for moist patterns, and water filled ruts (together with Gastropoda), or (3) low coverage of ground vegetation (together with free hunting spiders, Lycosidae). Different structures side by side (mature forest, selective cutting, open areas) may improve diversity on a forest scale. Small openings can serve as an important retreat for open habitat species. However, if clear-cuts become the dominant element, forest species maybe threatened. With selective cutting species richness of carabids is not improved; however, the remaining forest carabid species may be preserved during the early phase of the regeneration process.