Space-time variation of the relative abundance of Limnoperna fortunei in deep zones of São Gonçalo Channel, Rio Grande do Sul, Brazil

This work describes the spatial-temporal variation of the relative abundance and size of Limnoperna fortunei (Dunker, 1857) collected in São Gonçalo Channel through bottom trawl with a 0.5 cm mesh, at depths between 3 and 6 m. The estimative of mean relative abundance (CPUE) ranged from 2,425.3 individuals per drag (ind./drag) in the spring to 21,715.0 ind./drag in the fall, with an average of 9,515.3 ind./drag throughout the year. The estimated mean density of L. fortunei for the deep region of São Gonçalo Channel ranged from 1.2 to 10.3 ind./m², and it was recorded a maximum density of 84.9 ind./m² in the fall of 2008. The method of sampling using bottom trawl enabled the capture of L. fortunei under the soft muddy bottom of the channel, in different sizes ranging from 0.4 to 3.2 cm. This shows that the structure of the L. fortunei adult population under the bottom of the São Gonçalo Channel is composed mostly of small individuals (<1.4 cm), which represent up to 74% of the population collected.

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.

Ecological relations between mangrove leaf litter and the spatial distribution of the gastropod Melampus coffeus in a fringe mangrove forest

Leaf litter represents a food source to many organisms that may directly contribute to organic matter decomposition. In addition, the physical presence of these vegetal detritus contributes for the modification of some environmental areas and produce microhabitats that may act as a refuge against predators and desiccation for many animals. The pulmonate gastropod Melampus coffeus (Linnaeus, 1758) (Ellobiidae) is a very common specie in Atlantic Coast mangrove forests and feeds on fallen mangrove leaves. It was hypothesized that the spatial distribution of Melampus coffeus is directly affected by mangrove leaf litter biomass deposition. Thus, this research aimed at evaluating the spatial distribution of these gastropods in relation to the biomass of mangrove leaf litter through a twelve-month period. The study area was established in the middle estuary of Pacoti River, state of Ceará, Brazil where two adjacent zones with different topographic profiles were determined. Samples of Melampus coffeus and leaf litter were collected monthly, throughout a year, from the mangrove ground surface. The results indicated that the presence of twigs in mangrove litter favor the occupation by smaller individuals of M. coffeus, probably because smaller individuals are more susceptible to predator attacks and desiccation than larger ones, and twigs and branches may provide a safe microhabitat.

Ecomorphology and diet reflect the spatial segregation between two Siluriformes species inhabiting a stream of the Bodoquena Plateau, in Central Brazil

Pimelodella taenioptera Miranda Ribeiro, 1914 and Imparfinis schubarti (Gomes, 1956) are two of the most common fish species in Bodoquena Plateau streams, Paraguay basin. These species have benthic habits and subaquatical observations suggested that they present differentiation in their preference for mesohabitat types. Pimelodella taenioptera shows preference for slow waters, such as pools, while I. schubarti is associated to riffles. In this study we investigated if the known patterns of mesohabitat use of P. taenioptera and I. schubarti can be predict by their ecomorphological and trophic traits. We described the dietary habits and ecomorphological attributes of P. taenioptera and I. schubarti individuals, captured in the Parque Nacional da Serra da Bodoquena (PNSB), Mato Grosso do Sul state, central Brazil. Pimelodella taenioptera presented a more generalist diet, consuming a total of 23 different food items. Imparfinis schubarti have a diet based exclusively on aquatic insects. The ecomorphological analysis revealed that the species differed in relation to five morphological traits associated to habitat use (p <0.01). The results of this study reveal a clear functional dissimilarity between P. taenioptera and I. shubarti. The observed trophic and ecomorphological patterns are congruent with the known habitat use for these species and probably reflect the spatial and temporal variability on conditions and resources present in riffles and pools. Therefore, as expected, the morphological and feeding attributes represent predictive information related to mesohabitat use.

Assemblage of immature Odonata (Insecta, Anisoptera) in streams of the Mato Grosso do Sul State: spatial implications

ABSTRACT This study investigated the assemblages attributes (composition, abundance, richness, diversity and evenness) and the most representative genera of Odonata, Anisoptera at Água Boa and Perobão Streams, Iguatemi River basin, Brazil. Both are first order streams with similar length that are impacted by riparian forest removal and silting. Quarterly samplings were conducted from March to December 2008 in the upper, intermediate and lower stretch of each stream. The Mantel test was used to check the influence of spatial autocorrelation on the Odonata composition. Spatial variations in the composition were summarized by the Principal Coordinates Analysis (PCoA) using Mantel test residuals. The effects of spatial correlation on richness and abundance were investigated by the spatial correlogram of Moranʼs I coefficients. The most representative genera in each stream were identified by the Indicator Value Method. The spatial variations in the attributes of the assemblages were assessed using analysis of variance of null models. We collected 500 immature individuals of 23 genera and three families. Among the attributes analyzed only the composition and abundance showed significant spatial differences, with the highest mean abundance found in the Perobão Stream. Miathyria and Zenithoptera were the indicator genera of the Água Boa Stream and Erythrodiplax, Libellula, Macrothemis, Progomphus and Tramea were the indicator genera of the Perobão Stream.

A study of the endocervical columnar cells I - morphology and frequency

After the observation of many thousands of histological sections of the endocervical mucosa it became evident that its columnar cells present a great variety of aspects not only those of the surface of the canal but also those of the glands. A classification of these cells was made taking into account the staining affinity, the intensity staining of the cytoplasm, the presence or absence of cilia, the shape and location of the nucleus. The various combinations of these different data made possible the characterization of 26 types of cells which we labelled by the alphabetical letters. Two hundred and fifty cervices obtained by cervical amputation and by hysterectomy were studied. The uteri presented lesions in the course of routine laboratory examination. In each of the 250 histological sections there were specifically counted 2,000 columnar cells which cover the cervical canal and 2,000columnar cells which form the glands. A graphic representation of the frequency of both the superficial and glandular columnar cells was presented; this was given the name EPITHELIOGRAM. The variation of the cellular "composition" of each epithelium is discussed and the frequency of the various cellular types after the count of one million of cells is presented.

Spatial and seasonal trends of a natural population of Biomphalaria occidentalis in northeastern Argentina

This study aims to analyze the age of a population of Biomphalaria occidentalis on a pound of Riachuelo river basin, wich is one of the three most important Middle Paraná river affluents in Corrientes province. Samples were drawn from three stations, were spatial and temporal numerical variations of the snail, as well as its relation with different environmental parameters, mainly temperature, rainfall, pH and conductivity, were analyzed. Snail abundance is given in number of individuals/hour. The differences between the three sampling stations, estimated by nonparametric tests, was nonsignificant. A relative scale to the greatest shell diameter was employed to build the age pyramids. Temporal fluctuations of snail abundance correlated negatively with the highest monthly accumulated temperatures (P < 0.05). Although different floristic compositions were observed at the three stations, no significant numerical variations were detected in B. occidentalis spatial distribution. Reproductive activity took place between March-April and November with overlapping cohort system. During summer (December-Febuary) mortality increased along with temperature and reproductive activity was not evident.

Use of PCR for the determination of the frequency of the deltaF508 mutation in Brasilian cistic fibrosis patients

The [Delta]F508 mutation in the cystic fibrosis (CF) gene was studied in a population of 18 Brazilian CF patients and their 17 families by use of PCR and differential hybridization with oligonucleotides. In a total of 34 chromosomes considered, 12 (35%) carried the F508 deletion, a frequency much lower than that reported in most other populations. As a consequence, CF in Brazil would be predominantly caused by mutations different from the F508 deletion

Spatial and temporal distribution of anopheline larvae in two malarious areas in Sucre State, Venezuela

The spatial and temporal distribution of anopheline larvae was studied in two coastal malarious areas of Sucre, State, Venezuela. Seven habitat types were sampled in the village of Guayana and eight species of Anopheles were collected. Anopheles aquasalis was the predominant species collected and was most abundant in the brackish marsh habitat (71 larvae per 100 samples). It was most abundant during the rainy season. At the second location, Santa F e, six habitat types were sampled and four anopheline species were collected. Habitats where An. aquasalis was most abundant were temporary freshwater ponds (34 larvae per 100 samples) and mangroves (10.5 larvae per 100 samples). At this location it was also most abundant in the rainy season. During the dry season it was collected in small numbers in river pools (1.3 larvae per 100 samples) along with large numbers of An. pseudopunctipennis (479 larvae per 100 samples). Larval control could be an important component of the malaria control program because major habitats could be defined and presence and abundance of larvae was limited to specific times of year.

Simian malaria at two sites in the Brazilian Amazon - II: Vertical distribution and frequency of anopheline species inside and outside the forest

An anopheline survey was carried out in two simian malaria areas in the Brazilian Amazon, Balbina and Samuel, to determine the potential vectors of Plasmodium brasilianum. The most abundant and/or acrodendrophilic anophelines in the forest and the most likely vector were Anopheles mediopunctatus, An. nuneztovari, An. oswaldoi, An. triannulatus and An. shannoni. An. darlingi and An. marajoara were captured essentially in anthropic habitats outside the forest and are unlikely to be involved in the transmission of P. brasilianum among monkeys within the forests and from monkeys to man in their surroundings in the Amazon.

Mosquito Frequency and Feeding Habits in an Enzootic Canine Dirofilariasis Area in Niterói, State of Rio de Janeiro, Brazil

Heartworm, a chronic fatal mosquito-borne canine disease, is frequently diagnosed in dogs from the State of Rio de Janeiro, where its prevalence is 29.7% in the city of Niterói. Nevertheless it is rarely detected in cats (0.8%) from the same state. Dogs are the primary source of infection to mosquitoes, because cats either do not demonstrate microfilaremia or it is too low and transient for transmission. A mosquito survey was conducted in Itacoatiara, Niterói, from March 1995 to February 1996, using canine, feline and human baits. A total of 21 mosquito species (3,888 females) was collected and biting frequency was highest at dusk. The four species collected most frequently (88.9%) were: Aedes taeniorhynchus (30% of the total catch; with the peak in May/June); Culex quinquefasciatus (22.5%; August/October); Aedes scapularis (19.4%; August, October/November and January) and Culex declarator (17%; November/January). Human baits were attractive to these species and dogs were significantly more attractive to them than cats. Ae. taeniorhynchus, Cx. quinquefasciatus, Ae. scapularis, Cx. declarator and Cx. nigripalpus are the most likely mosquito species to transmit Dirofilaria immitis parasites to dogs and may transmit the parasite to humans. It is also suggested that the vector to cats belongs to the genus Culex

Ecology of mosquitoes (Diptera: Culicidae) in areas of Serra do Mar State Park, State of São Paulo, Brazil. I - Monthly frequency and climatic factors

The ecology of mosquitoes were studied (Diptera: Culicidae) in areas of Serra do Mar State Park, State of São Paulo, Brazil. Systematized monthly human bait collections were made three times a day, for periods of 2 or 3 h each, in sylvatic and rural areas for 24 consecutive months (January 1991 to December 1992). A total of 24,943 specimens of adult mosquitoes belonging to 57 species were collected during 622 collective periods. Coquillettidia chrysonotum was the most frequent collected mosquito (45.8%) followed by Aedes serratus (6.8%), Cq. venezuelensis (6.5%), Psorophora ferox (5.2) and Ps. albipes (3.1%). The monthly averages of temperature and relative humidity were inserted in the ten-year average limits of maximum and minimum of the previous ten-years. Rainfall accompanied the curve of the ten-year averages. Those climatic factors were influential in the incidence of some species; temperature: Anopheles cruzii, An. mediopunctatus, Ae. scapularis, Ae. fulvus, Cq. chrysonotum, Cq. venezuelensis, Runchomyia reversa, Wyeomyia dyari, Wy. confusa, Wy. shannoni, Wy. theobaldi and Limatus flavisetosus; relative humidity: Ae. serratus, Ae. scapularis, Cq. venezuelensis and Ru. reversa; rainfall: An. cruzii, Ae. scapularis, Ae. fulvus, Cq. venezuelensis Ru. reversa, Wy. theobaldi and Li. flavisetosus.

Frequency of specific anti-Toxoplasma gondii IgM, IgA and IgE in Colombian patients with acute and chronic ocular toxoplasmosis

We studied the frequency of specific anti-Toxoplasma IgM, IgA and IgE antibodies in serum of 28 immunocompetent Colombian patients, selected by ophthalmologists and with lesions that were compatible with ocular toxoplasmosis. Patients were classified in three groups: (i) group 1 consisted of ten patients with a first episode; (ii) group 2, with seven patients with a recurrence and (iii) group 3, consisted of eleven patients with chronic chorioretinal lesion without uveitis. We found that 10/28 (35%) of Colombian patients with ocular toxoplasmosis possessed at least one serological marker for Toxoplasma infection different from IgG. In group 1 (first episode), we found simultaneous presence of specific IgM plus IgA plus IgE in 1/10 (10%). In group 2 (recurrences) in 1/7 (14%) we found IgM and IgA test positives and in 1/7 (14%) we found IgM and IgE tests positives. In group 3 (toxoplasmic chorioretinal scar) the IgA serological test was positive in 2/11 (18%). These results show that serum IgM or IgA or IgE can be present during recurrences.

Frequency of human toxocariasis in Jos, Plateau State, Nigeria

The enzyme-linked immunosorbent assay (Elisa) was used to examine sera of 104 children and adults in Jos, Plateau State, Nigeria for anti-toxocaral antibodies, out of which 31 (29.8%) were reactive. The seropositive rates were 30.4% for adults, 29.6% for children, 34% for females and 25.9% for males. However, the differences were not significant by age and sex. A highly significant association (p < 0.001) was observed between seropositivity and geophagia but none between seropositivity and dog ownership (p > 0.05).