Mechanisms that favour the co-occurrence of morphologically and ecologically similar species in South America are potentially relevant, because two or more species often occur in sympatry. In the present study, we investigated possible mechanisms of resource partitioning between two sympatric species of foxes, the crab-eating fox Cerdocyon thous and the pampas fox Pseudalopex gymnocercus, in the National Park of Aparados da Serra in southern Brazil (29110 0 S, 50105 0 W). We considered three main niche dimensions -habitat, diet and time -and evaluated the overlap between the two species in these dimensions. We conducted the study from in an area composed of open grasslands and Araucaria forests. We studied the foxes by using a combination of scat analysis and direct observation. A comparison of their diet indicated that it was very similar for both species in all seasons (Pianka's indexes ranging from 0.920 to 0.957). The most common food item for both species of foxes was rodents, followed by coleopterans, birds and plant remains (seeds and fruits). As expected by the nichecomplementarity hypothesis, we detected differences along other niche axes. Pseudalopex gymnocercus seemed to occur only in open areas, including grasslands and dirt roads, whereas C. thous was more generalist in habitat use, occurring both inside and at the edge of forests. However, both fox species were common in grassland habitats, where they might compete for resources. The differences were more marked for activity time, with the crab-eating fox being significantly more nocturnal (circular mean of time of sighting = 23:39 h, SE = 56 min) than the pampas fox (circular mean= 19:56 h, SE = 64 min; Watson's F= 6.06, P= 0.02). We suggest that the larger C. thous could be limiting the activity of P. gymnocercus by interference competition.
ABSTRACT. This study established the spatial footprint of the industrial trawl fishing fleet operating off southeastern and southern Brazil between 2003 and 2011. It also provides estimates of the area swept by this fleet and the correspondent Utilization Index (swept area/available area) as measures of impact over the benthic ecosystem. Lastly, costs/benefits of trawling were addressed by the cumulative biomass landed during the study period expressed as a proportion of the cumulative swept area (Biomass-Swept Area Index). These variables were mapped and their patterns of spatial-temporal variability were associated with fishing strategies (shrimp trawling, slope trawling and pair trawling), latitudinal strata, depth strata, and substrate types. The trawl fishery footprint during the study period comprised 502,190 km 2 . The total area swept by trawling operations was 680,697.5 km 2 , 1.4 times the available area. Trawling impacts on the substrate were primarily produced by the dominant shrimp trawling strategy. In comparison with other strategies, these vessels used the most extensive shelf area, and disturbed more sand/mud habitat surface to obtain less landed biomass. Delimiting the trawl fishery footprint off southeastern and southern Brazil and its main core areas comprised a first step towards in evaluating impact on such areas, providing preliminary information for future ecosystem-based fisheries management and marine spatial planning strategies.
Bat coronaviruses (Bat‐CoVs) represent around 35% of all virus genomes described in bats. Brazil has one of the highest mammal species diversity, with 181 species of bats described so far. However, few Bat‐CoV surveillance programmes were carried out in the country. Thus, our aim was to jevaluate the Bat‐CoV diversity in the Atlantic Forest, the second biome with the highest number of bat species in Brazil. We analysed 456 oral and rectal swabs and 22 tissue samples from Atlantic Forest bats, detecting Alphacoronavirus in 44 swab samples (9.6%) targeting the RdRp gene from seven different bat species, three of which have never been described as Bat‐CoV hosts. Phylogenetic analysis of the amino acid (aa) sequences coding the RdRp gene grouped the sequences obtained in our study with Bat‐CoV previously detected in identical or congeneric bat species, belonging to four subgenera, with high aa identity (over 90%). The RdRp gene was also detected in three tissue samples from Diphylla ecaudata and Sturnira lilium, and the partial S gene was successfully sequenced in five tissues and swab samples of D. ecaudata. The phylogenetic analysis based on the partial S gene obtained here grouped the sequence of D. ecaudata with CoV from Desmodus rotundus previously detected in Peru and Brazil, belonging to the Amalacovirus subgenus, with aa identity ranging from 73.6% to 88.8%. Our data reinforce the wide distribution of Coronaviruses in bats from Brazil and the novelty of three bats species as Bat‐CoV hosts and the co‐circulation of four Alphacoronavirus subgenera in Brazil.
RESUMO Este trabalho investigou a maturidade sexual, o período reprodutivo e de recrutamento (ambos relacionados com a temperatura e a salinidade da água), e a proporção sexual de Xiphopenaeus kroyeri na Baía de Santos, SP. Os camarões foram capturados mensalmente, de junho de 2008 a maio de 2009, em quatro pontos de amostragem. Os indivíduos foram mensurados, analisados quanto ao sexo e o estágio de desenvolvimento reprodutivo foi determinado macroscopicamente. As fêmeas apresentaram valor médio de comprimento da carapaça (mm) maior que os machos e atingiram a maturidade fisiológica com valor superior, i.e., 25,5 mm para fêmeas e 16,8 mm para machos. O período reprodutivo foi contínuo, com maior proporção de fêmeas reprodutivas no outono. Apesar de não significativo, em fevereiro houve um pico similar a março de fêmeas reprodutivas. Entre agosto e outubro ocorreu um pico intermediário destas fêmeas que contribuiu para o recrutamento no verão. A menor quantidade de juvenis após a principal desova (fevereiro, março e abril) pode ser explicado pela migração ou pelo efeito da abertura da pesca, que ocorre em junho. A proporção entre os sexos foi próxima à 1:1, porém, em escala espacial, notou-se maior quantidade de fêmeas reprodutivas em locais mais rasos. Esta distribuição diferencial entre os sexos pode estar associada à estratégia reprodutiva das fêmeas, neste caso, áreas mais apropriadas para a desova. O atual defeso ocorre entre março e maio e, pelos resultados obtidos sobre a frequência de fêmeas reprodutivas, sugere-se a inclusão de fevereiro. ABSTRACT We investigated the sexual maturity, reproductive period and juvenile recruitment (both associated with salinity and temperature of bottom water) and sex-ratio of Xiphopenaeus kroyeri in Santos Bay, São Paulo. Monthly samples were obtained from
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