Social facilitation and food partitioning in the queenless ant Dinoponera quadriceps (Hymenoptera: Formicidae)

Social facilitation occurs when an animal is more likely to behave in a certain way in response to other animals engaged in the same behaviour. For example, an individual returning to the nest with food stimulates other ants to leave and to forage. In the present study we demonstrate the existence of new facets in the colony organization of Dinoponera quadriceps: a positive feedback between the incoming food and the activation of new foragers, and the occurrence of incipient task partitioning during the food sharing. Lower-ranked workers located inside the nest process protein resources and higher-ranked workers handle smaller pieces and distribute them to the larvae. In conclusion, D. quadriceps has a decentralized pattern of task allocation with a double regulatory mechanism, which can be considered a sophisticated aspect of division of labour in ponerine ants.

COMMON GOOSE BARNACLES LEPAS AUSTRALIS (THORACICA, PEDUNCULATA) ON DECEASED MAGELLANIC PENGUINS SPHENISCUS MAGELLANICUS (AVES)

Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)

Genital morphology of the male South American fur seal (Arctocephalus australis) and biological implications

Male capacity for spreading genes to a great number of descendents and to determine population dynamics depend directly on the genital organs. Morphological studies in pinnipeds are scarce and the functional meaning of some characteristics has never been discussed. We hypothesized that Arctocephalus australis (A. australis) shows morphophysiological adaptations in order to guarantee the perpetuation of the species in the unique annual mating season. Seven males, dead from natural causes, had their genital organs collected and fixed for morphological description. Some features differ from other described mammalian males and are closely related to the biology and reproductive cycle of this species, as the scrotal epidermis, absence of glandular portion in the ductus deferens and spermatogenic epithelium suggest a recrudescent testis period. The corona glandis exhibits a singular arrangement: its erectile border looks like a formation of petals and its association with the os penis gives a "lily-flower" form to this region. We propose the name margo petaliformis to this particular erectile border of the corona glandis because of its similarity to a flower corola. The male genital organs of A. australis show morphological features compatible with adaptation to environment requirements and reproductive efficiency.

The potentially toxic diatom Pseudo-nitzschia H. Peragallo in the Parana and Santa Catarina States, Southern Brazil

A taxonomic survey of the diatom Pseudo-nitzschia H. Peragallo was carried out in the Parana and Santa Catarina coasts, Southern Brazil. Samples were taken in various localities along the coastline using vertical hauls from the bottom to the surface. Electron microscopy revealed five species: the potentially toxic P. australis Frenguelli, P calliantha Lundholm, Moestrup & Has le, P multiseries (Has le) Has le and P pungens (Grunow ex Cleve) Has le (plus P pungens var. cingulata Villac), and the non-toxic P linea Lundholm, Has le & G. A. Fryxell. Southern Brazilian strains of P. calliantha and P multiseries have previously been shown to be toxic, raising concerns about a potential contamination of mussels and oysters being commercially grounded in the region. High morphological variability was observed in valve characters of P calliantha and P pungens, in some cases confirmed in the literature. In P calliantha there was a conspicuous differentiation in two morphotypes separated from each other by the width and the shape of the valve, and the density of the poroids. P linea has not previously been found in Brazilian waters, and P pungens var. cingulata is a new record in Western Atlantic waters. Future investigations using molecular techniques will elucidate whether the genetic variability corresponds to the morphological variation and unveil the possible existence of semicryptic species of Pseudo-nitzschia inhabiting the South Brazilian coast.

Bioaccumulation pattern of lanthanides in pteridophytes and magnoliophytes species from Atlantic Forest

The availability of chemical elements for plants is mainly dependent on the nature of the soil and characteristics of each species. The transfer factors of lanthanides from the soil to the tree leaves of the Atlantic Forest, Brazil, were calculated for one fern species (Alsophila sternbergii-Pteridophyta division) and four magnoliophytes species (Bathysa australis, Euterpe edulis, Garcinia gardneriana and Guapira opposita-Magnoliophyta division) obtained in two areas of Serra do Mar State Park and collected in two different seasons. Samples were analyzed by instrumental neutron activation analysis (INAA). The soil-to-plant transfer factor (TF = C(plant):C(soil)) in magnoliophytes species was correlated to the mass fraction of lanthanides in the soil, described by a exponential model (TF = a.C (soil) (-b) ). Despite the tree fern Alsophila sternbergii presented a hyperaccumulation of lanthanides, this species did not have a significant relationship between TF and mass fraction in soil. Results indicated that plants of Magnoliophyta division selected the input of lanthanides from the soil, while the same was not observed in Alsophila sternbergii.

Epidemiological characterization and risk factors associated with leptospirosis in the brazilian semiarid

Alves C. J., Alcino J. F., Farias A. E. M., Higino S. S. S., Santos F. A., Azevedo S. S., Costa D. F. & Santos C. S. A. B. 2012. [Epidemiological characterization and risk factors associated with leptospirosis in the brazilian semiarid.] Caracterizacao epidemiologica e fatores de risco associados a leptospirose em ovinos deslanados do semiarido brasileiro. Pesquisa Veterinaria Brasileira 32(6): 523-528. Universidade Federal de Campina Grande, Centro de Sa de e Tecnologia Rural, Unidade Academica de Medicina Veterinaria, Av. Universitaria s/n(o), Patos, PB 58700-970, Brazil. E-mail: clebertja@uol.com.br The aim of this investigation was to determine the herd-level and animal-level prevalence of leptospirosis in sheep from the semiarid of Paraiba State, Northeast Brazil, as well as to identify risk factors. Blood samples were collected from 1,275 sheep from 117 flocks in 19 counties in the Sertao mesoregion, Paraiba. For the serological diagnosis of leptospirosis the microscopic agglutination test (MAT) using 24 Leptospira spp. serovars as antigens was carried out. Of the 117 flocks studied 33 (28.20%) presented at least one seropositive sheep, and of the 1,275 animals 69 (5.41%) were seropositive with titers ranging from 100 to 3,200. Reactant serovars were Autumnalis (49.30%), Andamana (27.53%), Sentot (17.39%), Whitcomb (4.34%) and Australis (1.44%). Herd size > 48 sheep (odds ratio = 2.26; 95% CI = 1.33-5.07; p = 0.021) and participation in animal exhibits (odds ratio = 9.05; 95% CI = 0.96-85.71; p = 0.055) were identified as risk factors. The need was suggested for studies on the isolation of the agent, characterization of its pathogenicity and its economic impact on sheep flocks of the region, and sanitary control in sheep agglomerations was recommended.

Distribution patterns of a marsh vegetation metacommunity in relation to habitat configuration

The identification of the factors behind the distribution of plant communities in patched habitats may prove useful towards better understanding how ecosystems function. Plant assemblages are especially important for wetland productivity and provide food and habitat to animals. The present study analyses the distribution of a metacommunity of helophytes and phreatophytes in a wetland complex in oder to identify the effects of habitat configuration on the colonisation process. Ponds with wide vegetated shores and a short distance to a big (> 10 ha) wetland, had higher species richness. The average percentage of surface covered by each species in all the wetlands correlated positively with the number of patches occupied by that species. Moreover, the community presented a nested pattern (species-poor patches were subsets of species-rich patches), and this pattern came about by selective extinction and colonisation processes. We also detected the presence of some idiosyncratic species that did not follow nestedness. Conservation managers should attempt to maximise the vegetated shore width and to reduce the degree of isolation to enhance species richness. Furthermore, a single large and poorly isolated reserve may have the highest level of biodiversity in emergent vegetation species in this wetland complex, however, the particular ecological requirements of idiosyncratic species should also be taken into account when managing this type of community.

Genetic variability in mitochondrial and nuclear genes of Larus dominicanus (Charadriiformes, Laridae) from the Brazilian coast

Several phylogeographic studies of seabirds have documented low genetic diversity that has been attributed to bottleneck events or individual capacity for dispersal. Few studies have been done in seabirds on the Brazilian coast and all have shown low genetic differentiation on a wide geographic scale. The Kelp Gull is a common species with a wide distribution in the Southern Hemisphere. In this study, we used mitochondrial and nuclear markers to examine the genetic variability of Kelp Gull populations on the Brazilian coast and compared this variability with that of sub-Antarctic island populations of this species. Kelp Gulls showed extremely low genetic variability for nnitochondrial markers (cytb and ATPase) and high diversity for a nuclear locus (intron 7 of the beta-fibrinogen). The intraspecific evolutionary history of Kelp Gulls showed that the variability found in intron 7 of the beta-fibrinogen gene was compatible with the variability expected under neutral evolution but suggested an increase in population size during the last 10,000 years. However, none of the markers revealed evidence of a bottleneck population. These findings indicate that the recent origin of Kelp Gulls is the main explanation for their nuclear diversity, although selective pressure on the mtDNA of this species cannot be discarded.

General biochemical and immunological characteristics of the venom from Peruvian scorpion Hadruroides lunatus

This communication describes the general biochemical properties and some immunological characteristics of the venom from the Peruvian scorpion Hadruroides lunatus, which is the most medically relevant species in Peru. The soluble venom of this scorpion is toxic to mice, the LD50 determined was 0.1 mg/kg and 21.55 mg/kg when the venom was injected intracranial or intraperitoneally, respectively. The soluble venom displayed proteolytic, hyaluronidasic, phospholipasic and cardiotoxic activities. High performance liquid chromatography of the soluble venom resulted in the separation of 20 fractions. Two peptides with phospholipasic activity were isolated to homogeneity and their molecular masses determined by mass spectrometry (MALDI TOF). Anti-H. lunatus venom sera were produced in rabbits. Western blotting analysis showed that most of the protein content of this venom is immunogenic. H. lunatus anti-venom displayed consistent cross-reactivity with venom antigens from the new World-scorpions Tityus serrulatus and Centruroides sculpturatus venoms; however, a weaker reactivity was observed against the venom antigens from the old World-scorpion Androctonus australis Hector. (C) 2012 Elsevier Ltd. All rights reserved.

Serrumab: A human monoclonal antibody that counters the biochemical and immunological effects of Tityus serrulatus venom

In Brazil, the species Tityus serrulatus is responsible for the most severe cases of scorpion envenomation. There is currently a need for new scorpion anti-venoms that are more effective and less harmful. This study attempted to produce human monoclonal antibodies capable of inhibiting the activity of T. serrulatus venom (TsV), using the Griffin.1 library of human single-chain fragment-variable (scFv) phage antibodies. Four rounds of phage antibody selection were performed, and the round with the highest phage antibody titer was chosen for the production of monoclonal phage antibodies and for further analysis. The scFv 2A, designated serrumab, was selected for the production and purification of soluble antibody fragments. In a murine peritoneal macrophage cell line (J774.1), in vitro assays of the cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, and IL-10 were performed. In male BALB/c mice, in vivo assays of plasma urea, creatinine, aspartate transaminase, and glucose were performed, as well as of neutrophil recruitment and leukocyte counts. It was found that serrumab inhibited the TsV-induced increases in the production of IL-6, TNF alpha, and IL-10 in J774.1 cells. The in vivo inhibition assay showed that serrumab also prevented TsV-induced increases in the plasma levels of urea, creatinine, aspartate transaminase, and glucose, as well as preventing the TsV-induced increase in neutrophil recruitment. The results indicate that the human monoclonal antibody serrumab is a candidate for inclusion in a mixture of specific antibodies to the various toxins present in TsV. Therefore, serrumab shows promise for use in the production of new anti-venom.

Cuticular Hydrocarbon Variation of Castes and Sex in the Weaver Ant Camponotus textor (Hymenoptera: Formicidae)

Cuticular hydrocarbons play important roles as chemical signatures of individuals, castes, sex and brood. They also can mediate the regulation of egg laying in ants, by informing directly or indirectly the reproductive status of queens. In this study we asked whether cuticular hydrocarbon profiles are correlated with castes and sex of Camponotus textor. Cuticular hydrocarbons were extracted from part of a mature colony (80 workers, 27 major workers, 27 queens, 27 virgin queens and 27 males). Results showed that cuticular hydrocarbons varied quantitatively and qualitatively among the groups and this variation was sufficiently strong to allow separation of castes and genders. We discuss the specificity of some compounds as possible regulatory compounds of worker tasks and reproduction in C. textor.

Analysis of Insect Cuticular Compounds by Non-lethal Solid Phase Micro Extraction with Styrene-Divinylbenzene Copolymers

Insect cuticular hydrocarbons including relatively non-volatile chemicals play important roles in cuticle protection and chemical communication. The conventional procedures for extracting cuticular compounds from insects require toxic solvents, or non-destructive techniques that do not allow storage of subsequent samples, such as the use of SPME fibers. In this study, we describe and tested a non-lethal process for extracting cuticular hydrocarbons with styrene-divinylbenzene copolymers, and illustrate the method with two species of bees and one species of beetle. The results demonstrate that these compounds can be efficiently trapped by ChromosorbA (R) (SUPELCO) and that this method can be used as an alternative to existing methods.

Guatteria (Annonaceae) da Floresta Atlântica brasileira

Guatteria Ruiz et Pav. é o maior gênero de Annonaceae, com 307 espécies de distribuição neotropical. Caracteres reprodutivos constantes e vegetativos variáveis dificultam a caracterização das espécies. Como resultado do presente estudo são reconhecidas 15 espécies do gênero na Floresta Atlântica, Guatteria australis, G. campestris, G. candolleana, G. emarginata, G. ferruginea, G. latifolia, G. macropus, G. oligocarpa, G. pogonopus, G. pohliana, G. sellowiana, G. schomburgkiana, G. stenocarpa, G. tomentosa e G. villosissima. Oito nomes são sinonimizados e dois lectótipos são indicados. Chave, descrições, comentários taxonômicos, informações sobre fenologia, distribuição geográfica, hábitats de ocorrência, status de conservação e ilustrações são apresentados.

Indicadores químicos e biológicos na avaliação da qualidade do sedimento do Canal do Porto de Santos (SP, Brasil)

O Porto de Santos, inaugurado oficialmente em fevereiro de 1892, é o principal porto brasileiro e o maior da América Latina, responsável por cerca de um quarto da movimentação da balança comercial do país e mais de 60 milhões de toneladas de cargas diversas. Impactos na área decorrem da grande quantidade de embarcações e necessidade de dragagens periódicas, além da existência de uma extensa ocupação desordenada de suas margens e da presença de um complexo de indústrias e usinas na região. A qualidade do sedimento do Canal do Porto foi avaliada por meio de testes de toxicidade (agudo e crônico), de análises químicas (metais e hidrocarbonetos) e da estrutura da comunidade bentônica. O sedimento foi coletado em agosto de 2012 com pegador de fundo de 0,05m2 (3 réplicas para bentos) ao longo do Canal. Foram determinados 10 pontos de coleta para as análises químicas e de toxicidade, sendo 3 pontos para a análise da macrofauna bentônica (início, meio e fim do Canal). A distância entre o primeiro e o último ponto foi de 16 km. A avaliação conjunta dos resultados indicou um impacto maior na região mais interna do Canal. Na parte mais próxima ao complexo industrial de Cubatão foram observadas as maiores concentrações de metais e hidrocarbonetos, associadas a baixos valores de diversidade e riqueza, além de uma alta densidade do gastrópodo Heleobia australis. No centro do Canal do Porto, houve uma maior contribuição de indicadores de esgoto, presença de hidrocarbonetos e metais em concentrações relativamente altas, valores extremamente baixos de densidade, diversidade e riqueza da macrofauna bentônica, menor sobrevivência do anfípodo Tiburonella viscana (toxicidade aguda) e baixa taxa de eclosão de ovos do copépodo Nitokra sp (toxicidade crônica). Esse ponto encontra-se próximo a uma grande quantidade de habitações precárias, cujo esgoto é lançado diretamente no Canal.