Abstract Fiddler crabs are important components of intertidal benthic macrofauna in estuarine habitats. However, these invertebrates often inhabit areas under anthropogenic-driven changes. In this study, we evaluated the habitat quality and the population biology of the fiddler crab Uca maracoani (Latreille, 1802) in a mangrove area under anthropogenic influence, on the southern coast of São Paulo state, Brazil. Sediment samples for ecotoxicological analyses and data on the population biology of U. maracoani were collected monthly between October 2008 and October 2009. Contamination was observed in sediment samples from all months, indicating that benthic organisms inhabiting the study area are continuously exposed to toxicity. The sex ratio did not deviate from 1:1 for the whole population of U. maracoani, within any given month (except in October 2008, when males outnumbered females). Adult males and females showed a similar size, while juvenile females were larger than juvenile males, probably reflecting that females attained sexual maturity at a larger size than males. For both juvenile and adult stages, the major cheliped propodus length and height in males and the abdomen width in females showed positive allometry. The size-frequency distribution of the studied population varied from unimodal to bimodal. Juveniles were recorded in all months, suggesting the studied population has continuous recruitment. In contrast, ovigerous females were not found in the study area for several months. Although U. maracoani is continuously exposed to contamination present in the sediment, it presents a well-established population and seems to persist in the study area.

Abstract INTRODUCTION: We investigated the occurrence of coronary sinus abnormalities in the indeterminate form of Chagas disease (CD). METHODS: Differences between the maximum and minimum diameters of the coronary sinus (∆%) on echocardiography were evaluated in individuals with the indeterminate form of CD (n=14) and those without (n=16) CD. The association of the difference with abnormalities detected by echocardiography and myocardial scintigraphy was assessed. RESULTS: The mean Δ% values did not differ significantly between the groups. There was no correlation of the measurements with echocardiographic and myocardial scintigraphy findings. CONCLUSIONS: The coronary sinus evaluation revealed no differences between the groups.

ABSTRACT We investigated the infestation by Octolasmis lowei Darwin, 1851 in branchial chambers of the portunid Achelous spinimanus (Latreille, 1819), Arenaeus cribrarius (Lamarck, 1818), Callinectes danae Smith, 1869, and Callinectes ornatus Ordway, 1863. We evaluated how infestation is related to host maturity, molt stage, carapace width and sex. The infestation probability increases with host carapace width, and infested crabs were more likely to be adults in intermolt stage. Infestation prevalence did not differ between sexes, except for C. ornatus, in which females had higher infestation than males. Infestation intensity was higher for males than females in A. cribrarius and A. spinimanus, while C. ornatus showed an opposite pattern. Association of O. lowei with portunid seems to be tightly related to the biological traits of its host. Some of these traits, such as host size, maturity and molt stage, are likely to affect infestation in a similar way for all host species, while the effect of other traits, such as sex identity, seems to vary among hosts. We suggest a deeper understanding of the factors driving host use by generalist epibionts such as O. lowei depends on investigating their occurrence on a variety of potential hosts, as well as performing manipulative studies to evaluate the factors driving host preferences by this epibiont.

ABSTRACTThe spatial distribution of fauna associated to marine macroalgae has mostly been investigated considering a horizontal plane. However, the macroalgal substrates can present a three-dimensional structure. In this sense, investigating how the associated fauna varies throughout a vertical plane can contribute to understanding the distribution of these organisms. The brown macroalga Sargassumpresents a vertical stratification along its thallus and harbors an amphipod fauna with a variety of feeding habits. In this work, we tested if the amphipod assemblage varies along different portions of the Sargassum thallus. We collected whole Sargassum stenophyllum thalli, as well as isolated basal and distal portions, from a rocky shore located on the north coast of São Paulo, in southeastern Brazil. The composition of amphipod families varied according to the Sargassum portion and the families Corophiidae, Caprellidae and Hyalidae accounted for most of the differences. Moreover, the basal portion of Sargassum had a higher diversity of amphipod families than the distal one, which may be related to differences regarding habitat complexity (herein, measured as algal biomass) between these portions. Detritivores (such as Corophiidae) were more associated to the basal portion and herbivores to the distal portion (Hyalidae) or along the whole Sargassum thallus (Ampithoidae). The variation of amphipod assemblage along Sargassum thallus seems to result from the interaction between the fauna natural history and the differences in conditions and physical structure along the algal thallus. In this sense, the vertical stratification of Sargassum can add another source of variation to the spatial distribution of associated fauna.

Stalked barnacles Octolasmis lowei Darwin, 1851 are frequently found attached to decapod crustaceans. Their epibiotic association depends on many factors, which are mainly related to characteristics of the host's biology. This study evaluated the infestation and distribution of stalked barnacles in the branchial chambers of crabs, and analyzed the data with respect to the host's sex, maturity stage, molt cycle and size. The crab species Arenaeus cribrarius Lamarck, 1818, Callinectes danae Smith, 1869, Callinectes ornatus Ordway, 1863, Hepatus pudibundus Herbst, 1785, Libinia ferreirae Brito Capello, 1871, and Persephona punctata Linnaeus, 1758 were sampled and found to be infested by O. lowei. No juvenile crabs were infested. The prevalence of infestation by O. lowei was significantly different among C. danae, C. ornatus, and H. pudibundus males and females. All infested hosts were in the intermolt period. The mean size of infested crabs was larger than that observed for non-infested individuals. Internally, stalked barnacles were concentrated on the central gills or walls and floor of branchial chambers, suggesting that these gills provide more favorable conditions for the settlement and development of these epibionts. These results highlight the relationship between epibiont infestation and host biology, as well as the role of decapod crustaceans as a suitable substrate for the development of stalked barnacle O. lowei.

We describe paternal care in two pentatomid bugs, Lopadusa (Lopadusa) augur Stål, 1860 and Edessa nigropunctata Berg, 1884. Field and laboratory observations showed that males remain with their eggs and early hatched nymphs, while females abandon the eggs after oviposition. Guarding males defensive behaviors towards their clutches were similar to those described for guarding females of pentatomids. Since there is no detailed information on the internal phylogeny of Pentatomidae, it is not possible to make a robust inference on whether paternal care in L. augur and E. nigropunctata has arisen independently or not. If the latter, the two new cases of paternal care we describe here represent the fifth event of independent evolution of this rare behavioral trait in Heteroptera.

Neste texto apresentamos um breve histórico dos Encontros de Aracnólogos do Cone Sul (EACS), uma reunião de aracnólogos sul americanos realizada a cada dois anos desde 1997. Os dados foram obtidos a partir dos livros de resumos e mostram a importância dessas reuniões para o desenvolvimento da pesquisa em aracnologia na América do Sul.

Here we present a brief history of the "Encontros de Aracnólogos do Cone Sul (EACS)", a meeting of mostly South American arachnologists held every two years since 1997. Data compiled from the abstract books show how these meetings have contributed towards the development of South American arachnological research.

It was sampled the litter frogs at altitudinal sites of a semideciduous mesophytic forest located at Sena do Japi (Jundiaí, São Paulo, 23º17'S, 47º00'W, 800-1300m altitude, 1500mm rain/year). Forty two plots of 8x8m were sampled in the dry/cold season of 1995: 21 at a Higher Site (HS) (1000m) and 21 at a Lower Site (LS) (850m). The plots were evenly located near, mid-distance, and far from the stream-bed. It was found a total of five species, three at each site. Eleutherodactylus guentheri comprised 83% of the individuals at HS and E. juipoca 67% at LS. The density of individuals was higher at HS and near the stream. The greater density at HS may be due to greater humidity there, provided by mist. The frogs may aggregate in wetter places (stream edges) in the dry/cold season. The studied sites represent harsh and early successional environments and both these factors may be acting together to produce the low observed diversity.