Composition and structure of a Miridae (Hemiptera, Heteroptera) assemblage from a relict of deciduous rainforest in southern Brazil

A two-year study was carried out to evaluate the composition, abundance and species richness of Miridae from Parque Estadual do Turvo, municipality of Derrubadas, state of Rio Grande do Sul, Brazil. Samplings were made in the springs of 2003 and 2004 (October), and autumns of 2004 and 2005 (May), using a beating tray method, along two trails of the park. Sampling effort (hours x collectors) in the quantitative collections totaled 153 hours. Two-hundred mirid specimens of 50 species were collected. The most abundant mirid was Prepops setosipes (Reuter, 1910), representing 23% of the collected individuals, followed by Collaria capixaba Carvalho & Fontes, 1981 (10.5%) and Tropidosteptes cribratus (Stål, 1860) (7%), the latter recorded in all sampling periods. The highest abundance was observed in the springs of 2003 and 2004, with 53 and 78 individuals, respectively. Rarefaction method showed that estimated species richness was higher in autumn/2004 than in the other sampling periods, and higher along Yucumã than in Garcia trail. Besides a higher species richeness, Yucumã had more exclusive species than Garcia trail. The percent of species represented by one or two specimens in quantitative samplings (singletons and doubletons) was 60%. Additional samplings including hand collection, random beating tray and light trap collections added 20 species not recorded in the quantitative samplings.

Diversity and structure of microcrustacean assemblages (Cladocera and Copepoda) and limnological variability in perennial and intermittent pools in a semi-arid region, Bahia, Brazil

Temporary wetlands undergo recurrent drought due to the scarcity of water, which disrupts the hydrological connectivity with adjacent aquatic systems. However, some environments retain water for longer periods, allowing greater persistence of the community. The current study evaluated differences in the microcrustacean assemblages and limnological variability between perennial and intermittent pools in a semi-arid region of Brazil. The abiotic features (water temperature, pH, total alkalinity, electrical conductivity and depth) of intermittent pools were affected more than perennial pools due to loss of water volume. This may have contributed to a higher average richness and diversity index in some intermittent pools and differences in the structure of the assemblages. The lowest species richness and diversity were recorded where physical factors, such as a large quantity of suspended solids and variability in the electrical conductivity of the water and pH, make the environment unsuitable for these organisms. These results suggest that community development in intermittent pools is interrupted by the dry season; when the water returns, due to rainfall or rising groundwater, each pond undergoes a different process of colonization. In these circumstances, the biological importance of temporary aquatic environments is clear, since such pools provide shelters and have an important role in the maintenance of the regional diversity of aquatic environments.

Community structure of metazoan parasites of silverside, Odontesthes bonariensis (Pisces, Atherinopsidae) from Argentina

The helminth communities of silverside, Odontesthes bonariensis (Valenciennes, 1835), from two Argentinean lagoons were studied and compared at component community and infracommunity levels. Nine helminth species were found: five digeneans (Austrodiplostomum cf. mordax, Ascocotyle (Phagicola) cf. diminuta, Ascocotyle sp., Thometrema bonariensis and Saccocoelioides sp.); two nematodes (Contracaecum sp. and Hysterothylacium sp.); one acanthocephalan (Wolffhugelia matercula) and one cestode (Cangatiella macdonaghi). Odontesthes bonariensis is a new host record for five parasite species. Richness, diversity and number of helminths in silversides from Salada Grande lagoon were higher than in those from Lacombe lagoon. This could be related with lagoon size, abundance of mollusks and fish-eating birds, and size and diet of silversides captured in each lagoon. In Salada Grande lagoon the helminth community of silversides was dominated by the allogenic and generalist species A. cf. mordax; while the autogenic and intermediate specialist species C. macdonaghi was dominant in Lacombe lagoon. Host sex did not affect richness, diversity or total abundance, whereas host size was positively correlated with these attributes, except diversity in Salada Grande lagoon.

Diversity of social wasps (Hymenoptera, Vespidae) in Cerrado biome of the southern of the state of Minas Gerais, Brazil

An inventory of social wasps in Cerrado biome of the southern of the state of Minas Gerais was performed. A comparison between field and Riparian Forest areas was made in relation to species richness; correlations between diversity, sample methods and environmental factors were conducted. A total of 32 species was registered and Polybia fastidiosuscula de Saussure, 1854 was the most abundant species. The higher richness was in the Cerrado Field, as well as the highest diversity index. The temperature and rainfall had significant correlation with species richness and a significant variation in richness between dry and wet seasons was observed. Polybia fastidiosuscula was more abundant in the Riparian Forest during the dry season and in the Cerrado Field during wet season. The study area showed a great diversity of social wasps, with record both widely distributed species such as rare species, which indicates the quality and potential area for future studies.

Temporal and spatial variation of rocky shores intertidal benthic communities in Southeast Brazil

The relationships between environmental factors and temporal and spatial variations of benthic communities of three rocky shores of the state of Espírito Santo, Southeast Brazil, were studied. Sampling was conducted every three months, from August 2006 to May 2007, using intersection points. Chthamalus bisinuatus (Pilsbry, 1916) (Crustacea) and Brachidontes spp. (Mollusca) were the most abundant taxa, occupying the upper level of the intertidal zone of the rocky shore. The species richness was higher at the lower levels. The invasive species Isognomon bicolor (C. B. Adams, 1845) (Mollusca) occurred at low densities in the studied areas. The clustering analysis dendrogram indicated a separation of communities based on exposed and sheltered areas. According to the variance analyses, the communities were significantly different among the studied areas and seasons. The extent of wave exposure and shore slope influenced the species variability. The Setibão site showed the highest diversity and richness, most likely due to greater wave exposure. The communities showed greater variation in the lower levels where environmental conditions were less severe, relative to the other levels.

Bird community in an Araucaria forest fragment in relation to changes in the surrounding landscape in Southern Brazil

The dynamics of the bird community in a small forest fragment was evaluated along seven years in relation to changes in the surrounding landscape. The study area is an Araucaria forest fragment in Southern Brazil (state of Paraná). The sampling period covered the years 1988 through 1994 and the mark-release-recapture method was utilized. The landscape analysis was based on Landsat TM images, and changes in exotic tree plantations, native forest, open areas (agriculture, pasture, bare soil, and abandoned field), and "capoeira"(native vegetation < 2 m) were quantified. The relationship between landscape changes and changes in abundance diversity of forest birds, open-area birds, forest-edge birds, and bamboo specialists was evaluated. Richness estimates were run for each year studied. The richness recorded in the study area comprised 96 species. The richness estimates were 114, 118 and 110 species for Chao 1, Jackknife 1 and Bootstrap, respectively. The bird community varied in species richness, abundance and diversity from year to year. As for species diversity, 1991, 1993 and 1994 were significantly different from the other years. Changes in the landscape contributed to the increase in abundance and richness for the groups of forest, open-area and bamboo-specialist species. An important factor discussed was the effect of the flowering of "taquara" (Poaceae), which contributed significantly to increasing richness of bamboo seed eaters, mainly in 1992 and 1993. In general, the results showed that landscape changes affected the dynamics and structure of the bird community of this forest fragment over time, and proved to have an important role in conservation of the avian community in areas of intensive forestry and agricultural activities.

Bird communities in three forest types in the Pernambuco Centre of Endemism, Alagoas, Brazil

The Pernambuco Center of Endemism (PCE) in northeastern Brazil is highly fragmented and degraded. Despite its potential conservation importance the bird fauna in this area is still relatively unknown and there are many remnant fragments that have not been systematically surveyed. Here, we report the results of bird surveys in five forest fragments (one pioneer, two ombrophilous and two seasonal). In total, 162 taxa were recorded, 12 of which are endemic to the PCE. The frequency of endangered species was lower than what has been reported in studies from the same area and most of the taxa considered to be at risk of extinction were sub-species of uncertain taxonomic validity. The comparatively low number of endemic/threatened species may be due to the small size of the fragments in the present study - a consequence of the high levels of habitat loss in this region. Analysis of species richness patterns indicates that ombrophilous forest fragments are acting as refuges for those bird species that are most sensitive to environmental degradation.

Effects of environmental factors on community structure of Leptophlebiidae (Insecta, Ephemeroptera) in Cerrado streams, Brazil

We analyzed the effects of environmental factors on abundance, species richness, and functional group richness of Leptophlebiidae in 16 sampling points along four Cerrado streams. Across three periods of 2005, we collected 5,492 larvae from 14 species in stream bed substrate. These species belong to three functional feeding groups: scrapers, filtering collectors and shredders. The abundance and species richness were not affected by water quality, but habitat quality related to presence of riparian vegetation had positive effects on the abundance of shredders. Our results add important information on the natural history of the species and functional groups of aquatic insects and also provide relevant data for the monitoring and conservation of streams in the Brazilian Cerrado.

Bats (Mammalia, Chiroptera) of an urban park in the metropolitan area of Rio de Janeiro, southeastern Brazil

Some bat species are able to adapt to urban areas, where they find food and roosts. Despite the high number of parks in Brazilian cities, they did not yet raise the interest of most zoologists, except for some surveys of birds and butterflies. The objectives of the present study were: (i) to inventory the bat species of Quinta da Boa Vista (QBV), a large (25 ha) urban park centrally located in densely populated Rio de Janeiro, which is Brazil's second largest metropolis; (ii) to compare the species richness observed in roosts with the richness recorded through mist netting in flight routes and near fruiting fig trees; and (iii) to analyze recaptures of bats marked in this park and recaptured in other sites and vice-versa. Sampling totaled 104 sampling nights resulting in 3,256 captures (including 133 recaptures) between April 1989 and December 2004. We also sampled roosts and received some specimens from park visitors and city workers. We documented 21 bat species, predominantly large frugivores. The number of expected species for this park was 24.0 ± 4.6, and the total sampled represented 87.5% of the expected. The recapture of bats marked in surrounding forest fragments and in QBV shows the importance of urban parks for the maintenance of bat diversity. Inspection of roosts produced two species that had not been captured with other methods. Sampling near fruiting fig trees did not differ in terms of richness from sampling carried out far from these trees or during their non-fruiting periods.

Variation of the ichthyofauna along the Goioerê River: an important tributary of the Piquiri-Paraná basin

The construction of reservoirs is considered an important source of impacts on the fish fauna, severely altering the structure of the assemblage. This paper aimed to describe the structure of the fish assemblage of the Goioerê River, determining its longitudinal distribution and patterns of species dominance. The evaluation of its longitudinal variation in the diversity and abundance of the fish assemblage was conducted in July and October 2004 and January and May 2005. The collections were carried out near the headwaters (Gurucaia), middle stretch (Olaria), just above the falls (Paiquerê) and downstream (Foz). Forty-four species were captured. The Gurucaia fish assemblages differed significantly from Olaria, Paiquerê and Foz. The Olaria assemblages differed significantly from the Foz. Gurucaia showed the lowest diversity and abundance of species. Astyanax aff paranae Eigenmann,1914 (78% of the total) was found to be dominant at this site. Almost the same species richness was found at Olaria and Paiquerê, although Olaria had the greatest abundance of individuals. Astyanax aff paranae, Cyphocharax modestus (Fernández-Yépez, 1948) and Astyanax altiparanae Garutti & Britski, 2000 were the top three dominants and comprised over 71% of the total number of fish caught. At Paiquerê, Astyanax altiparanae, Hypostomus aff ancistroides (Ihering, 1911) and Loricariichthys platymetopon Isbrücker & Nijssen, 1979 composed 58% of the catches. Thirty-one species were recorded at Foz, which presented the greatest richness. The most abundant species were Apareiodon affinis (Steindachner, 1879), Galeocharax knerii (Steindachner, 1879) and A.altiparanae, which contributed to 50% of the total catches in this environment.These results record the fish biodiversity and how the community is longitudinally structured in the Goioerê River, and also demonstrate how this type of evaluation is important to understanding the fish community patterns and finding solutions to problems related to the conservation and management of the basin.

Diversity and habitat preference of medium and large-sized mammals in an urban forest fragment of southwestern Amazon

We assessed the species composition and abundance of medium and large-sized mammals in an urban forest fragment in the Brazilian Amazon, and recorded the preference of some species for particular phytophysiognomies. We placed nine transects with 20 sand plots each in three phytophysiognomies: open rainforest with a dominance of bamboos (OFB), open rainforest with palm trees (OFP), and dense rainforest (DF). We calculated species abundance as the number of records/plot.day, in a total of 2,700 plots.day. We recorded twelve mammal species; Sylvilagus brasiliensis (Linnaeus, 1758) and Dasyprocta fuliginosa (Wagler, 1831) were the most abundant. The results differed among phytophysiognomies: DF presented the highest mammal diversity, whereas the species composition of OFP was less similar than that of other phytophysiognomies. Rodents showed higher preference for OFP and Sylvilagus brasiliensis was more abundant in OFB. The study area showed high species richness, with the occurrence of mesopredators, but there was a predominance of common species adaptable to disturbed environments, which reflects the severe isolation degree of the forest fragment and the hunting pressure that is still present.

Diversity, composition and phenology of araneid orb-weavers (Araneae, Araneidae) associated with riparian forests in southern Brazil

The Araneidae is a speciose family including web-spinning spiders that are very abundant in various terrestrial ecosystems. Several studies demonstrate that changes in vegetation surrounding rivers, streams and brooks affect the associated araneofauna. The aim of this research was to compare differences found in diversity (abundance and richness), composition and phenology of Araneidae spiders sampled in different habitats in four riparian forest catchments in southern Brazil. Samples were taken from riparian forests in four rivers of Rio Grande do Sul State: Piratini, Camaquã, Sinos and Maquiné rivers, each in a different hydrographic basin. Samples were taken twice seasonally on each basin during two years, sampling the araneofauna of the tree-shrub strata with beating tray. Six transects were employed on each basin, two per habitat: edge with grassland, forest interior and river edge. Araneids totalled 20 genera and 65 species. Comparing riparian forests significant differences are found. Spider abundance differed among riparian forests as well as species richness. Overall, Piratini river riparian forest had the higher abundance and richness for Araneidae; the lower values were in Sinos river forest. The stronger degradation and fragmentation of the riparian forests of Sinos river probably influenced the results, with human disturbance gradients associated negatively to web building. We present data on the diversity of these spiders, which were very abundant in the riparian forest interior and very rich in species in the grassland/riparian forest edge. Species composition also differs among the studied habitats (the above plus river/riparian forest edge). For the most abundant species the phenological pattern across the seasons was also analysed.

An ecological and comparative analysis of parasites in juvenile Mugil liza (Pisces, Mugilidae) from two sites in Samborombón bay, Argentina

ABSTRACT Mugil liza Valenciennes, 1836 is an economically important food fish and has been recommended for aquaculture in South America. A total of 278 fishes were collected in the spring and summer of 2009 and 2010. These fish were sorted into sample groups according to their size class. We used Bayesian statistics and 95% credible intervals for each parameter tested were calculated. Fish studied harbored a total of 15 different species of parasites. Diversity of parasite species found on Mugil liza was greatest at the S.R.C. collection site, but evidenced a lower species richness than at A.R. site. The 1st size fishes of both sites evidenced greater parasite diversity than either 2nd or 3rd size fish. Differences observed could be explained by the different use of habitat types at the two sites or differential susceptibility to infection by parasites. The dominance of D. fastigatainfluenced observed results of lower community diversity indexes. New works elucidating different parasite life cycles within juvenile and adults ofM. liza in Argentina, promise to be important for determining the risk of the parasitism by zoonotic metacercariae A. (P.) longa and use of this fish as food and an economic resource, and the possible use of mullet parasites in other promising fields as indicators of biodiversity, and/ or water contamination.

Metazoan parasite fauna of the bigeye flounder, Hippoglossina macrops, from Northern Chile. Influence of host age and sex

The metazoan parasite fauna of Hippoglossina macrops (n = 123) from northern Chile (30°S) is quantitatively described for the first time, and the role of host age and sex was evaluated. Twelve parasite species were recovered, including 5 ectoparasites (2 Monogenea, 2 Copepoda and 1 Piscicolidae) and 7 endoparasites (1 Digenea, 3 Cestoda, 2 Acanthocephala, and 1 Nematoda). The copepod Holobomolochus chilensis, the monogenean Neoheterobothrium sp., the adult acanthocephalan Floridosentis sp. and the hirudinean, Gliptonobdella sp. are new geographical and host records. The most prevalent ectoparasitic species were the monogenean, Neoheterobothrium sp. and the copepod, H. chilensis. Among endoparasites, the acanthocephalans Floridosentis sp. and Corynosoma australe were most prevalent and abundant. Prevalence and mean intensity of infection for most parasitic species were not affected by host sex, however the prevalence of Floridosentis sp. was significantly greater in males. Intensity of infection was positively correlated with host age for Neoheterobothrium sp., and negatively correlated for Floridosentis sp. and H. chilensis. The helminth species richness of the host H. macrops was lower compared to related flatfishes from the Northern Hemisphere. The relationship of the helminth fauna of H. macrops, its feeding habits and ecological habitats are discussed.

Diversity of biting midges of the genus Culicoides Latreille (Diptera: Ceratopogonidae) in the area of the Yacyretá Dam Lake between Argentina and Paraguay

The Culicoides communities have been analyzed between 1993/1998 in the area influenced by the Yacyretá Dam Lake (Paraná River, Argentina-Paraguay). Adults of Culicoides were collected monthly by using CDC light traps exposed for 24 h in 9 sampling sites located at both margins of the river; 21 species were recorded. Highest values of species richness were recorded during 1993/1994, being Quiteria and Corpus the sites with the higest number of species (10 and 11, respectively). The species diversity was elevated in Quiteria, Zaimán, Candelaria, Santa Tecla, Capitán Meza and Corpus (Shannon's diversity index 1.0-1.9) while Corateí, Ituzaingó and Aguapey showed less richness and diversity. The more abundant species were C. insignis, C. venezuelensis, C. leopoldoi, C. limai, C. flinti, C. debilipalpis, C. paraensis and C. guttatus. C. insignis, potential vector of bluetongue virus (BTV) to domestic and wild rumiants in the Neotropical region, is the predominant species in the area and was the only species widely distributed. C. paraensis, a proven vector of Oropouche virus to humans, is a common and abundant species. C. pusillus and C. lahillei, potential vectors of BTV and a filarial parasite, respectively, were occasionally collected. The taxonomic structure of communities was constant during the study period. The occasional species were not characteristic to one particular site and their presence could be related to non-intrinsic conditions.