bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial heterogeneity and its influence on Copaifera langsdorffii Desf. (Caesalpiniaceae)
Authors: Resende Júlio Carlos França , Klink Carlos Augusto , Schiavini Ivan
Published: April 2005

Population dynamics and structure of young individuals of the tree Copaifera langsdorffii Desf. (Caesalpiniaceae) were studied in the gallery forest of the Panga Ecological Station, Uberlândia, MG, Brazil. Three distinct habitats were recognized in this forest, Dike, Middle and Edge zone. Four annual surveys of plant height, diameter at plant base and density were made between 1993 and 1996. The species showed an aggregated distribution in all three habitats. Population structure in all four surveys presented the typical reversed "J" form, characteristic of populations in local regeneration. For the whole population, mortality rates during the four years were constant and low (average of 4.8 % per year), while recruitment declined during the same period (average of 2.9 % per year). The C. langsdorffii seedling and sapling intraspecific density had a negative effect on growth, possibly due to the action of herbivores and pathogens.
Hunter color dimensions, sugar content and volatile compounds in pasteurized yellow passion fruit juice (Passiflora edulis var. flavicarpa) during storage
Authors: Sandi Delcio , Chaves José Benício Paes , Sousa Antônio Carlos Gomes de , Parreiras June Ferreira Maia , Silva Marco Túlio Coelho da , Constant Patrícia Beltrão Lessa
Published: April 2005

Changes in Hunter L, a and b values, glucose, fructose and sucrose contents, concentration of four volatile compounds (ethyl butirate, ethyl caproate, hexyl butirate and hexyl caproate) and furfural, were studied in yellow passion fruit juice (Passiflora edulis var. flavicarpa) pasteurized at 75ºC/60s, 80ºC/41s or 85ºC/27s, during storage at room temperature (25±5ºC) and refrigeration (5±1ºC) for 120 days. While the sucrose content decreased, the glucose and fructose contents increased significantly over storage time. The Hunter L and b values behaved similarly, with a tendency to decrease over time, inversely to Hunter a value. Volatile compound concentrations also decreased over time, inversely to the furfural content. Pasteurization at 85ºC/27s resulted minimum changes in the studied passion fruit characteristics, while that at 75ºC/60s was the most harmful. Storage under refrigeration tended to keep the best quality characteristics of the juice.
Responses of Neomegalotomus parvus (Hemiptera: Alydidae) to color and male-lured traps
Authors: Ventura Maurício Ursi , Panizzi Antônio Ricardo
Published: April 2005

In 1998, the relative responses of Neomegalotomus parvus (Westwood) (Hemiptera: Alydidae) to colors in traps were assessed in the field. Colors were printed in white alkaline paper and covered with transparent plastic. Printed colors were black, green, yellow, red and blue. Treatments also included white paper and aluminum foil. Green traps captured more bugs than the other traps (except yellow). Yellow traps caught significantly more N. parvus males than blue, black and aluminum traps. White, red and blue traps captured significantly more N. parvus males than black traps. In 1999, the same treatments were used and additionally included the factor presence (X absence) of males in cages in the traps. Four males were confined in the cages together with pigeon pea seeds and water. Control traps received only pigeon pea seeds and water. No responses were found for color comparisons. Male-lured traps captured significantly more males than control traps.
Soil erosion determination in a watershed from northern Paraná (Brazil) using 137Cs
Authors: Andrello Avacir Casanova , Appoloni Carlos Roberto , Guimarães Maria de Fátima
Published: April 2005

The objective of this work was study the soil losses or gains in a watershed in the municipal district of Cambé, Paraná using 137Cs as marker for the determination of soil redistributions. A transect sampling was used to evaluate the influence of different tillage on soil erosion. One point, located in a forest area was sampled and analyzed to determine the reference inventory of cesium-137 deposited by fallout. The average value of the reference inventory was 292 Bq m-2. The cesium-137 inventory of the transect samples varied from 80 Bq m-2 to 403 Bq m-2. The sampling points in pasture presented soil losses. The sampling points in coffee plantation did not present losses or gains. The sampling points in soybean cultivated areas presented soil losses.
Initial segmentation patterns of microspores and pollen viability in soybean cultured anthers: indication of chromosome doubling
Authors: Cardoso Milena Barcelos , Kaltchuk-Santos Eliane , Mundstock Elsa Cristina de , Bodanese-Zanettini Maria Helena
Published: April 2005

Anthers obtained from flowers buds of soybean cultivar IAS-5 were cultured in two basal culture media (B5 and B5 long). Cytological examinations of the in vitro anthers were performed during the first 20 days of culture to assay the viability (by propionic-carmine and fluorescein diacetate tests) and the stage of development of pollen grains. The frequencies of viable pollen grains varied significantly between bud sizes on the propionic-carmine analysis. The basal culture media and bud size had no clear effect on the frequencies of binucleate symmetrical and multinucleate pollen grains. Chromosome counts of metaphasic microspores throughout the culture period showed microspores with higher ploidy level in addition to normal chromosome number (n=20).
Isolation of natural inhibitors of papain obtained from Carica papaya latex
Authors: Monti Rubens , Contiero Jonas , Goulart Antonio José
Published: April 2005

Studies were carried out to natural papain inhibitor from papaya latex. Fresh latex from green fruits of Carica papaya was collected and immediately transported in ice bath to the lab, from which three fractions with inhibitor effect of esterase papain activity were isolated by latex dialysis, Sephadex G-25 gel filtration and ionic exchange chromatography in SP-Sephadex C-25. The isolated fractions, identified as inhibitors I and II, showed a negative reaction with ninhydrin; however, the fraction identified as P-III showed positive reaction with ninhydrin. Kinetics data showed non-competitive inhibition (inhibitor I) and uncompetitive (inhibitors II and P-III).
Fish community composition, seasonality and abundance in Fortaleza Lagoon, cidreira
Authors: Schifino Lúcia Cabral , Fialho Clarice Bernhardt , Verani José Roberto
Published: April 2005

The Fortaleza Lagoon belongs to the Southern Tramandaí subsystem, formed by lagoons disposed linearly on the north-south direction (30º 08’S, 50º 13’W). The objective of this study was to describe some aspects related to the composition of the fish community of Fortaleza Lagoon. Samples were collected monthly from November 1998 to October 1999. The specimens were captured at four previously determined points in the lagoon, and classified in five orders, 12 families and 22 species. Cyphocharax voga, Hyphessobrycon luetkenii, Oligosarcus jenynsii, Oligosarcus robustus and Loricariichthys anus were more abundant species. Amongst the sampled species only two could not be characterised as freshwater species: Centropomus sp (marine) and Lycengraulius grossidens (estuarine). The ichthyofauna of the lagoon was predominantly composed by constant species.
Population dynamics of Musca domestica (Diptera: Muscidae): experimental and theoretical studies at different temperatures
Authors: Tardelli Carina Aparecida , Godoy Wesley Augusto Conde , Mancera Paulo Fernando Arruda
Published: April 2005

In the present study, the population dynamics of M. domestica was evaluated at two different temperatures, 20 and 30ºC. The dynamics was modeled using a density-dependent model of population growth. The temperatures investigated in this study produced no qualitative change in terms of dynamic behaviour, i. e. the population dynamics of M. domestica was characterized by a stable equilibrium at both temperatures. However, the steady state was influenced by the results obtained at different temperatures. The difference between the eigenvalues obtained at the two temperatures was probably the cause of the difference between the distinct steady states. The implications of these results for the population dynamics of M. domestica are discussed.
Predaceous ant fauna in new sugarcane fields in the state of São Paulo, Brazil
Authors: Rossi Marcelo Nogueira , Fowler Harold Gordon
Published: April 2005

Predaceous ant fauna present in natural sugarcane field plantations in the state of São Paulo, Brazil, was evaluated by using sardine baits sampling technique. Three-month-old sugarcane plants were used for ant fauna estimation in two sugarcane mills, São João and Barra Mill. Twelve 30m X 30 m (900 m²) plots were previously delimited in each sugarcane mill for ant sampling. Ants were sampled in each plot by placing nine sardine baits in 12 mm X 75 mm plastic tubes. In the São João Mill, the predominant ant species observed was Solenopsis saevissima, followed by Dorymyrmex sp. 1, Pheidole sp. 2, and Crematogaster sp. 1. Considering only ant genus, Solenopsis, Pheidole, Dorymyrmex, and Crematogaster, were predominant. In the Barra Mill, the predominant ant genus sampled was Solenopsis, followed by Pheidole, Crematogaster, and Dorymyrmex. As generalist predatory ants could be one of the reasons for the naturally low levels of D. saccharalis infestation on sugarcane in the state of São Paulo, this study could be helpful for the researchers to gain knowledge about the fauna of predaceous ants which acted as predators of eggs and early larval stages of D. saccharalis in Brazil.
Improved method for isolation of coupled mitochondria of Araucaria angustifolia (Bert.) O. Kuntze
Authors: Mariano André Bellin , Kovalhuk Leonardo , Valente Caroline , Maurer-Menestrina Juliana , Pereira-Netto Adaucto Bellarmino , Guerra Miguel Pedro , Carnieri Eva Gunilla Skare
Published: April 2005

A method for the isolation of coupled mitochondria from the callus of Araucaria angustifolia is described for the first time. Mitochondria were isolated from embryogenic callus of A. angustifolia. They were metabolically active, able to sustain oxidative phosphorylation as shown by respiratory control ratio values, which were about 2.4 when respiring on succinate as substrate. Oxygen uptake experiments, using freeze-thawed disrupted mitochondria, showed the presence of alternative rotenone-insensitive NAD(P)H dehydrogenases, which were stimulated by Ca2+. The procedure now described for the isolation of A. angustifolia mitochondria is an important new tool, allowing the investigation of mitochondrial bioenergetics and metabolism and physiology of plants.
Physical-chemical characteristics and fatty acids composition in dairy goat milk in response to roughage diet
Authors: Torii Marcelo Shizuo , Damasceno Júlio César , Ribeiro Luciano da Rocha , Sakaguti Eduardo Shiguero , Santos Geraldo Tadeu dos , Matsushita Makoto , Fukumoto Nelson Massaru
Published: April 2005

The objective of the present work was to evaluate the physical-chemical characteristics (density, pH, acidity, fat, protein, lactose and total of solids contents) and milk fatty acids composition (C: 4 to C: 20) in response to roughage sources (alfalfa hay T1; oat hay T2 and maize silage T3). Nine Saanen lactating goats were used, in a triple Youden square design (3 animals x 2 periods). There was no treatment effects in the physical-chemical variables in the univariate analyses; by multivariate analyses three distinct patterns of fatty acids could be defined: milk with greater quantity of short chain fatty acids and acids C17:1omega7 e C18:2omega6 (T1); milk with equivalent amounts of short, medium and long chain fatty acids (T2); and milk with greater amounts of acids C16:1omega7, C17:0, C18:1omega9 and C20:0 (T3). These results indicated that the roughage sources used in the diet of lactating dairy goats affected the fatty acids composition, without altering the milk physical-chemical characteristics. The acids more sensitive to the treatment effects were: C10:0, C12:0, C14:0, C16:0, C16:1omega7, C18:0 and C18:3omega6.
Species composition and spatial distribution of a stream fish assemblage in the east coast of Brazil: comparison of two field study methodologies
Authors: UIEDA V. S. , UIEDA W.
Published: April 2005

The species composition and spatial distribution of a fish assemblage were studied in three reaches of a river in the east coast of Brazil: a section of rapids (upper), another of water flowing on plain terrain (lowland) and the other of a mangrove environment. Two methods were employed with the purpose of estimating their effectiveness in naturalistic studies of tropical fish assemblages. One method consisted of underwater observations and the other was characterized by catches using gears such as fish traps, sieves and fishing rods. Both methods showed that their effectiveness is dependent upon the characteristics of the environment and the biology of the species. In areas of high water transparency and flow speed, rocky substrate and no submerged marginal vegetation (upper reach), the employment of the traditional gears was quite inefficient, despite the excellent conditions for underwater observations. In areas of clear water and high flow speed with abundant submerged marginal vegetation (lowland and mangrove), the gears were rather efficient yielding excellent results when coupled with direct observation methods. Since the abiotic characteristics of a stream change longitudinally, it is appropriate to employ different methods in the study of the ichthyofauna composition and distribution in order to reduce the constraints imposed by sampling methods in running waters.
Growth of broad-nosed caiman, Caiman latirostris (Daudin, 1802) hatchlings, fed with diets of animal origin
Authors: PINHEIRO M. S. , LAVORENTI A.
Published: April 2005

The study was carried out to evaluate the growth rate of broad-nosed caiman, Caiman latirostris hatchlings, fed on four animal protein diets: (a) dead poultry from a poultry farm; (b) dead piglet from nursery and farrowing house in a swine farm; (c) whole tilapia (Tilapia rendalli e Oreochromis niloticus); and (d) a balanced mixture of a, b, and c sources. Sixteen seven-month old caimans, average weight of 208 g and, 38 cm of total lenght (TL) were distributed in four treatments. Four groups of four caimans each were placed in cement enclosures inside a greenhouse. Diets were supplied at the average rate of 97.8% ± 34.8% of the body weight per week (average and standard deviation; wet weight basis). Body mass and total length of caimans were measured every 30 days for six months (Nov. 1995-April. 1996). An analysis of variance with repeated measures was performed. Diets provided suitable growth for weight and TL (mean ± standard deviation, respectively): (a) 2,157 ± 743 g and 79.5 ± 6.9 cm; (b) 1,811 ± 222 g and 75.7 ± 1.9 cm; (c) 2,431 ± 780 g and 80.7 ± 5.8 cm; (d) 1,683.5 ± 736 g and 74.5 ± 7.2 cm. There was no significant effect of diet on weight, but diet effect on TL of hatchlings approached significance (p < 0.10). It is concluded that all diets have good potential, in growth sense, to be used in commercial farms or ranches and for captivity propagation programs of caimans.
Temporal and spatial patterns on serra, Scomberomorus brasiliensis (Teleostei, Scombridae), catches from the fisheries on the Maranhão coast, Brazil
Authors: BATISTA V. da , FABRÉ N. N.
Published: April 2005

The displacement pattern of the serra, Scomberomorus brasiliensis, in North-eastern Brazil was analyzed from landing data recorded from the fleet fishing serra. Serra fishery has two seasons: from September to February (demersal species plus serra), and from March to August (almost only large amounts of serra). S. brasiliensis relative abundance increases similarly along the coast from March, but decreases first on the West coast from June. Records indicate that serra is near the coast at least until September/October in Eastern grounds. From October to March (strongest spawning season) there is no record of shoals on the coast. We concluded that the Maranhão coast is just a part of the migration circuit of S. brasiliensis that may exceed 300 nautical miles.
African dung beetle Onthophagus gazella Fabricius (Coleoptera: Scarabaeidae) esterase isozymes
Authors: MARTINS E. , CONTEL E. P. B.
Published: April 2005

African beetles Onthophagus gazella from both sexes were analyzed by electrophoresis for an investigation of esterase isozymes using alpha-naphthyl propionate and methylumbelliferyl propionate as substrates. Only one of the esterases (Est. 6) reacted with one of the substrates (alpha-naphthyl propionate). Six areas of activity were found, two of them being polymorphic (Est. 3 and Est. 4). For presence of Est. 3, 337 individuals were analyzed, including descendants of 32 controlled crossings: two alleles were identified, whose frequencies are Est. 3A = 0.447 and Est. 3B = 0.553. The population is in equilibrium for this locus (qui-square = 4.18; 0.2 > P > 0.1). For Est. 4, 338 individuals, descendants of 32 controlled crossings, were analysed. In this case, three alleles were identified whose frequencies are: Est. 4A = 0.277; Est. 4B = 0.661; and Est. 4C = 0.062. The population is not in equilibrium for this locus (qui-square = 40.259; p < 0.001). Two esterases were detected only in the pupal stage and another one in larvae. Of the 23 loci analyzed in these insects up to now, 3 are polymorphic (13%), which indicates very low variability in the population here studied.
The effect of treatment with melatonin upon the ultrastructure of the mouse pineal gland: a quantitative study
Authors: REDINS G. M. , REDINS C. A. , NOVAES J. C.
Published: April 2005

In order to evaluate melatonin implication in the regulating of its own secretory process by pinealocytes, we used morphometric techniques for transmission electron microscopy. In mice treated with 100 mg of melatonin (N-acetyl-5-methoxy-tryptamine) by daily subcutaneous injection, we observed a decrease in number and volumetric density of lysosomes. Our results showed that melatonin influences the secretory activity of pinealocytes and participates in a complex secretory regulating mechanism.
Substrate use and selection in sympatric intertidal hermit crab species
Authors: TURRA A. , DENADAI M. R.
Published: April 2005

Coexisting hermit crabs may competitively interact for shells and microhabitats, mainly when shell availability is habitat-related. Three species of Clibanarius (C. antillensis, C. sclopetarius, and C. vittatus) coexist in the intertidal region of Pernambuco Islet, Araçá Region, São Sebastião Channel, southeastern Brazil. This study evaluated crab preferences for four substrate types used by these species in nature (rocky shore, pebbles, sand, and mud) in allopatric (single species) and sympatric (three species) treatments in simulations of high tide and low tide. The substrate preference of the three hermit crabs did not vary between low and high tide situations. At low tide the crabs either moved into holes in the highly complex rocky substrate or buried themselves in mud. Substrate selection may explain the patterns of substrate use in nature only for C. vittatus. Clibanarius antillensis and C. sclopetarius showed closer similarities in the pattern of substrate selection in the sympatric treatment with the substrate use in nature than in allopatric treatment, indicating a positive influence (dependence) of the presence of one species on the presence of another. Use of sub-optimal substrates, mainly by C. antillensis, may be caused by other factors such as its low desiccation tolerances. If competition for space takes place among these species, it would be more intense between C. sclopetarius and C. vittatus given their higher overlap in substrate preference than between them and C. antillensis.
Social behavior between mothers × young of sloths Bradypus variegatus SCHINZ, 1825 (Xenarthra: Bradypodidae)
Authors: SOARES C. A. , CARNEIRO R. S.
Published: April 2005

This study is a contribution to the ex situ and in situ conservation and preservation of Sloths. The behavioral records of the social interaction between mothers and offspring allow the detection of important learning interactions and psychomotor development. The results provide valuable information that may assist in improving management conditions of captive orphan progeny. They also favor a more effective monitoring of released or transferred specimens. Age is of fundamental importance in deciding what is important during the release, transfer, or reintroduction of the species.
The gross anatomy of the nervous system of Bothriurus bonariensis (L. C. KOCH, 1842) (Scorpiones, Bothriuridae)
Authors: HORN A. C. M. , ACHAVAL M.
Published: April 2005

The nervous system of the order Scorpiones appears to have a common organizational structure. The combination of an anatomical study using methylene blue as the contrast medium together with a histological analysis using hematoxylin-eosin and Heindenhain´s iron hematoxylin techniques permitted the identkfication of a large number of nerves in B. bonariensis. Many of these are also present in a variety of other species of scorpions, belonging to distinct families of the order Scorpiones. Nevertheless, two pairs of nerves from B. bonariensis originating in the cheliceral ganglion, one pair of esophageal nerves and one pair of nerves from the aortic arch, appear to diverge from this basic organization. They have not been previously described, nor have any equivalents been reported in research on other scorpion species, in which the current homological criteria have been employed.
Life history of the gall-maker Eugeniamyia dispar Maia, Mendonça-Jr. & Romanowski, 1996 (Diptera, Cecidomyiidae)
Authors: MENDONÇA M. de S.,Jr. , ROMANOWSKI H. P.
Published: April 2005

The development of the galls of the midge Eugeniamyia dispar Maia, Mendonça-Jr. & Romanowski, 1996 (Diptera: Cecidomyiidae) was monitored weekly on its host plant, Eugenia uniflora (Myrtaceae). The work was carried out in the urban area of Porto Alegre, RS, Brazil, from October 1993 to September 1995. Galls were collected from the field and raised in the laboratory to obtain adults. The females oviposit on young leaves of the host plant, with the first instar larvae inducing the gall, which is unilocular. The last instar larvae drop to the soil to pupate and later emerge as adults. The galls occur from late August to early June, when young leaves of the host can be found, with populations peaking during the summer. So far this species is only known from the two southernmost states of Brazil (RS and SC).
Spatial distribution of Plecoptera nymphs in streams of a mountainous area of Central Brazil
Authors: BISPO P. C. , FROEHLICH C. G. , OLIVEIRA L. G.
Published: April 2005

In this paper the spatial distribution of Plecoptera nymphs in the Almas' River basin, Pirenópolis, GO, was studied. Two Surber samples, each comprising 20 sampling units and totalling 2 m², were taken in each of the 13 stations, one during the rainy season (January 1994) and the second during the dry season (July 1994). In 5 of these stations, monthly samplings were made from June 1993 to July 1994; in these, temperature, velocity, discharge, electrical conductivity and pH were measured. Regional rainfall was also obtained. To ascertain the distribution of nymphs in the habitat, a separate sample was taken. Of the factors considered, the most important affecting the spatial distribution of the stonefly nymphs were altitude, stream order, and anthropic influence. Locally, the genera Anacroneuria and Kempnyia showed clumped distributions, but the data for Gripopteryx and Tupiperla were inconclusive due to low numbers.
On the natural diet of Daphnia laevis in the eutrophic Pampulha reservoir (Belo Horizonte, Minas Gerais)
Authors: ESKINAZI-SANT'ANNA E. M. , MAIA-BARBOSA P. M. , BARBOSA F. A. R.
Published: April 2005

The aim of this study was to assess the major food items ingested by adult specimens of Daphnia laevis within the eutrophic Pampulha reservoir in Belo Horizonte, Minas Gerais, Brazil. The gut content was analyzed after addition of sodium hypochlorite and also through the examination of dissected guts under scanning electron microscopy. The results showed that Chlorophyceae was the main food item ingested, representing c. 80.5% of the total ingested food. Moreover, Eutetramorus fottii, Coelastrum pseudomicroporum and Oocystis lacustris, the dominant phytoplankton species within the reservoir, were the most frequent cells found in the gut contents. Euglenophyta also represented an important food item accounting for 15% of the ingested material, including mainly Trachelomonas volvocina and Euglena oxyuris, although less abundant in the reservoir (< 10% of total phytoplankton). Blue-green algae occurred at much lower percentages in the guts than in the phytoplankton. A small amount of undigested Microcystis aeruginosa colonies were also found in the gut content of D. laevis. Scanning electron microscopy results showed that, besides phytoplankton cells, a great amount of abiogenic material was also ingested. The amount of this inorganic material increased considerably in the tract (from 15% to 75% of the gut content), when a peak of D. laevis was observed in the reservoir. Our assumption is that the ingestion of this inorganic material can be a strategy used by D. laevis to obtain additional food supply.
Genetic diversity in different populations of sloths assessed by DNA fingerprinting
Authors: MORAES N. , MORGANTE J. S. , MIYAKI C. Y.
Published: April 2005

In this study we analyzed a population of Bradypus torquatus with individuals originally distributed in different localities of Bahia, and two populations of B. variegatus with individuals from Bahia and São Paulo States. Using the DNA fingerprinting method, we assessed the genetic variability within and between populations. Analysis of the DNA profiles revealed genetic similarity indices ranging from 0.34 ± 0.07 to 0.87 ± 0.04. Similar low levels of genetic variability were found only in isolated mammalian populations or among related individuals. This study presents the first analyses of genetic diversity in sloth populations.
Aerobic and anaerobic degradation of tannic acid on water samples from Monjolinho reservoir (São Paulo, SP, Brazil)
Authors: CUNHA-SANTINO M. B. , BIANCHINI Jr. I. , SERRANO L. E. F.
Published: April 2005

In order to describe the transformations of tannic acid during its degradation (under aerobic and anaerobic conditions) incubations were performed. To evaluate the oxygen consumption, the tannic acid was added to 1 L of water sample from Monjolinho's reservoir (22º00'S and 47º54'W); these solutions were aerated and the dissolved oxygen was monitored for 16 days, the anaerobic process was avoided. For the anaerobic and aerobic degradation, the dissolved organic carbon and the acid tannic concentrations were estimated on the samples days. The results were fitted to first-order kinetic model, being possible to verify that during the 16 days the oxygen uptake was 3.6 mg.L-1, the deoxygenation rate (kD)of this process was 0.39 day-1. The degradation coefficients were calculated through the decay of the tannic acid and organic carbon concentrations. In the aerobic process, the global decay coefficient (kG) was 0.36 day-1 and in the anaerobic 0.28 day-1. Overall, the obtained degradation coefficients suggest that the bacterioplankton of the Monjolinho's reservoir possess a high capacity of polyphenols degradation.
The sea basses Diplectrum formosum and D. radiale (Serranidae) as followers of the sea star Luidia senegalensis (Asteroidea) in Southeastern Brazil
Authors: GIBRAN F. Z.
Published: April 2005

This paper reports on Luidia senegalensis being followed by Diplectrum formosum and D. radiale in shallow soft bottoms of southeastern Brazilian coast, and comments on this association between bottom-dwelling organisms and serranids. Following is likely due to the serranid's inquisitive behaviour, and both juvenile and adult sea basses acted as followers, feeding on disturbed or exposed prey due to sea star activities.
Astyanax scabripinnis (Pisces: Characidae) hemoglobins: structure and function
Authors: LANDINI G. F. , SCHWANTES A. R. , SCHWANTES M. L. B.
Published: April 2005

Electrophoretic patterns of hemoglobins, Root effect, Bohr effect in blood and stripped hemoglobin, Hb-O2 affinity GTP modulation of Astyanax scabripinnis (lambari), caught at three different altitudes in Ribeirão Grande, near Campos do Jordão (São Paulo), are described. All populations showed the same electrophoretic patterns: two cathodal components in starch gel. Normal Bohr effect values were found in these three populations both in blood (phi = -0,11) and stripped hemoglobin (phi = -0,12). Different blood O2 affinities collected in fish of these 3 populations were detected. GTP has a large influence on Hb-O2 binding properties in A. scabripinnis. Stripped hemoglobin shows small Root effect. The addition of triphosphated nucleotides increases this effect. GTP is more effective than ATP on enhancing Root effect. Oxygen availability in water can be the factor responsible for differences found in blood O2 affinity.
Functional behavior of tortoise hemoglobin Geochelone denticulata
Authors: TORSONI M. A. , STOPPA G. R. , TURRA A. , OGO S. H.
Published: April 2005

The hemolysate from Geochelone denticulata contains two main hemoglobin components, as shown by ion exchange chromatography and polyacrylamide gel electrophoresis (PAGE). Electrophoresis under dissociating conditions showed three types of globin chains. The apparent molecular mass, as determined by gel filtration on Sephadex G-200, was compatible with tetrameric Hb, which was unable to polymerize. The G. denticulata Hb has a P50 value of 9.56 mm Hg at pH 7.4. The Hb oxygenation appears to be under the control of organic phosphates and hydrogen ion since it is strongly affected by those species. In the presence ATP or IHP the P50 values increased to 29.51 mm Hg and 54.95 mm Hg, respectively, at pH 7.4. The n50 was generally lower than 1.5 in stripped Hb, suggesting a dissociation of tetramers. In the presence of organic phosphates n50 values increased to approximately 2.5. The Bohr effect was evident in oxygen equilibrium experiments. The hematocrit (32%) and Hb concentration (5.7 mM as heme) of G. denticulata blood were substantially larger than those of G. carbonaria, but the methemoglobin levels were similar in both species, approximately 1%. Thus, the oxygen capacity of blood appears to be higher in G. denticulata than in G. carbonaria, particularly considering the functional properties of their Hbs, which would guarantee the survival of animals.
Ion fluxes of Metynnis hypsauchen, a teleost from the Rio Negro, Amazon, exposed to an increase of temperature
Authors: BALDISSEROTTO B. , VAL A. L.
Published: April 2005

The aim of this study was to investigate the effect on an increase of temperature on the net ion fluxes on Metynnis hypsauchen, a teleost species from the Rio Negro. Fish were collected in the Anavilhanas archipelago, Rio Negro, Amazon. After 24 h adaptation fish were placed in individual chambers served with a steady flow of recirculated water. Na+ and Cl- fluxes were determined at 26 and 33ºC. After 18 h in the chambers, fish presented an influx of Na+ and Cl-, and the temperature raise to 33ºC led to an efflux of both ions, which remained even after 6 h in this temperature. Six hours were not enough to promote a significant reduction of net ion effluxes, but certainly the fluxes would be in net balance after a longer period of time, since this species can be exposed to this temperature in its natural environment.
Population dynamics of Cosmoclopius nigroannulatus Stal (Hemiptera, Reduviidae) in tobacco culture
Authors: JAHNKE S. M. , REDAELLI L. R. , DIEFENBACH L. M. G.
Published: April 2005

The role of predators influencing populations of insects considered as pests is extremely important for agroecosystems. The population ecology of Cosmoclopius nigroannulatus, a predatory reduvid associated with the tobacco culture was investigated aiming to study the population dynamics of adults, along the culture cycle. In an experimental plot of approximately 300 m², in Porto Alegre (30°0'S; 51°13'W), RS, Brazil, 270 tobacco plants were grown; each plant identified by alphanumeric coordinates. Using the mark-release-recapture method, daily samplings were done from August to December 1999, and three times a week from this date until April 2000. The adults were captured by hand, marked, sexed and released on the same plant they were captured. The individual number and plant coordinate were registered. Population estimates were analyzed by the Fisher-Ford method. In 107 sampling occasions, 604 individuals were marked, 273 males and 331 females. Three generations of C. nigroannulatus were registered during the culture cycle. The colonizing generation was represented by 14 males and 15 females (a sex ratio of 0.48), the first by 109 males and 137 females (0.44) and the second by 150 males and 179 females (0.46). The estimated daily survival rate varied between generations decreasing from 98% in the colonizing generation to 87% in the second. The observed longevity or permanence time in the experimental area varied significantly among generations, being at about 40 days in the colonizing generation, 13 days in the first and 5 days in the second. It was observed that as the population increases, the survival and/or permanence time in the area decreases, suggesting a relation between this and a decline in the available resources probably with an associated increase in intra-specific competition.
Biflagellate spermatozoon structure of the hermaphrodite fish Satanoperca jurupari (Heckel, 1840) (Teleostei, Cichlidae) from the Amazon River
Authors: MATOS E. , SANTOS M. N. S. , AZEVEDO C.
Published: April 2005

The ultrastructural features of the sperm were studied in the hermaphroditic teleost Satanoperca jurupari HECKEL, 1840 from Amazon River. Spermatocytes, spermatids and sperm develop in the testicular cysts among the different oocyte stages. Different stages of early spermatocyte development, mainly the ones with synaptonemal complexes were often observed. The mature spermatozoa belong to the introsperm type, with a short head (~ 3 mm long and 1.3 mum wide) without acrosome, short midpiece (~ 1.2 mum long and 1.8 mum wide) containing several mitochondria surrounding two centrioles and forming a mitochondrial collar. They have two flagella (each ~15 mum long) each of which has a common 9 + 2 microtubular pattern. Each flagellum has two opposite lateral cytoplasmic extensions that begin about 3 mum the midpiece still close to the end piece of flagellum.
Exploitation of Erythrina dominguezii Hassl. (Fabaceae)nectar by perching birds in a dry forest in western Brazil
Authors: RAGUSA-NETTO J.
Published: April 2005

Among the vertebrate pollinated plants, the genus Erythrina includes tree species in which birds are the pollen vectors. Two groups in this genus may be distinguished: a) the hummingbird, and b) the perching bird pollinated species. Erythrina dominguezii is included in the second group and occurs in deciduous/semi-deciduous forests in the southwestern neotropics. I studied the exploitation of Erythrina dominguezii nectar by perching birds in a dry forest in western Brazil. Six perching bird species from two distinct groups (Psittacidae: Brotogeris chiriri, Nandayus nenday, Aratinga acuticaudata; Icterinae: Psarocolius decumanus, Icterus cayanensis, I. icterus) consumed its nectar. The two most important consumers were Brotogeris chiriri (51.5% of the flowers visited by birds) and Psarocolius decumanus (20%). While B. chiriri was a flower predator, P. decumanus removed the nectar without damaging the flowers which it opened by inserting its large bill between the standard and the keel. Nandayus nenday, Aratinga acuticaudata, and I. icterus exploited the nectar like P. decumanus, and presumably also contributed to pollen transfer. As the flowering in E. dominguezii was intense and synchronous during the dryest period of the year, and its nectar was highly consumed by birds, the present data suggest that the nectar of this species may be important as an alternative resource to frugivorous/omnivorous birds when other resources are scarce.
Seasonal diet shift in a Tetragonopterinae (Oateichthyes, Characidae) from the Ubatiba river, RJ, Brazil
Authors: Mazzoni R. , Rezende C. F.
Published: April 2005

In the present study, we describe feeding habits of Deuterodon sp. from the Ubatiba River and explore if diet changes according to a temporal cycle of dry and wet seasons. We observed that Deuterodon sp. fed on an extremely high diversity of items ranging from organic matter, sediment (sand plus quartz parts), algae, seeds and leaves to animal organisms, such as, crustaceans, oligochaets and several life stages of terrestrial and aquatic insects, indicating an omnivorous diet. An important shift in the use of feeding resources was also registered; animal and vegetal items had alternated importance between both seasons. Allochthonous vs. autochthonous items analysis showed predominance of allochthonous items during dry season while no significant differences were registered during wet season.
Infestation and distribution of the mite Varroa destructor in colonies of africanized bees
Authors: Moretto G. , Leonidas J. de M.
Published: April 2005

Whereas in several parts of the world varroa is the major pest affecting apiculture, in others the parasite is unknown to many beekeepers because its damage to bees is minor. The impact of the mite Varroa destructor is related to the climatic conditions and the races of Apis mellifera bees in each region where the pest exists. In the present study, the current level of infestation by the mite was assessed to determine the evolution of the pest in Africanized bee colonies in Southern Brazil. This level of infestation was considered low: approximately two mites per one hundred adult bees. This result is similar to that obtained for the same apiary almost five years ago and for others distributed in various regions of Brazil. In the present study, we also estimated the total varroa population and its distribution among brood and adults in each bee colony.
Genetic characterization of the peptidases of Polistes versicolor (Hymenoptera: Vespidae)
Authors: Del Lama M. A. , Ferreira K. M.
Published: April 2005

Starch gel electrophoresis with L-leucyl-beta-naphthylamide as substrate revealed five aminopeptidases in extracts of Polistes versicolor. These enzymes are presumably products of five structural gene loci. All but Lap¹ aminopeptidases exhibited differential distribution in the developmental stages and in the tissues. Five dipeptidases were revealed with different dipeptides. These enzymes exhibited significant differences in their substrate preferences, but a more homogeneous distribution throughout ontogenetic developmental stages than did aminopeptidases. Electrophoretic variants of Lap4 and PepA² were detected and although a low intralocus heterozygosity was found due to the low frequency of these variants, phenotypical segregation observed at these loci in pupae extracts of some colonies points to the occurrence of more than one egg-laying female. Otherwise, the detection of Lap4 allozyme restricted to nests of one area suggests low dispersion ability of the adults of Polistes versicolor.
Relative feeding specialization may depress ontogenetic, seasonal, and sexual variations in diet: the endemic lizard Cnemidophorus littoralis (Teiidae)
Authors: Teixeira-Filho P. F. , Rocha C. F. D. , Ribas S. C.
Published: April 2005

We investigated the feeding habits of the teiid lizard Cnemidophorus littoralis in the markedly seasonal habitat of Restinga da Barra de Maricá (22º57'S, 43º50'W), Rio de Janeiro State, Brazil, to evaluate to what extent its diet is ontogenetically, sexually, and/or seasonally conservative. Lizard stomach contents were analyzed, identified, counted, estimated for volume (in mm³), and grouped in four classes (active, sedentary, and clumped preys, and plant material). The relative contribution of each food class to the total prey volume consumed by adult males and females and juveniles was compared in three ways: between juveniles and adults, sexes, and seasons (wet and dry). Sexual dimorphism in head size was tested by comparing head width and jaw length using analysis of covariance (ANCOVA). Isopterans were the most important prey item, occurring in 93% of the lizard stomachs examined and corresponding to 96.4% of total prey content and 69.7% of total prey volume. They occurred in high frequencies in the stomachs of C. littoralis throughout all study months. We found no sexual, ontogenetic, or seasonal differences in C. littoralis diet although the sexes differed significantly in head width. We concluded that isopterans are the main item in the diet of C. littoralis in Restinga da Barra de Maricá, both for juveniles and adults. The lack of seasonal, sexual, or ontogenetic variation in its diet results from the massive consumption of these insects. Isopterans are small, occur in clumps, and are available year-round, and thus are an advantageous food item for the active forager C. littoralis. We also found sexual dimorphism in the head size of C. littoralis: males have wider heads than females. This dimorphism, however, does not seem to be related with the diet of the species, and is probably a result of sexual selection.
Zooplankton community structure of two marginal lakes of the River Cuiabá (Mato Grosso, Brazil) with analysis of Rotifera and Cladocera diversity
Authors: Neves I. F. , Rocha O. , Roche K. F. , Pinto A.A.
Published: April 2005

In the present study, two small lakes on the margins of the River Cuiabá were analyzed regarding taxonomic composition and population densities of the zooplankton. Diversity was evaluated for two groups, Rotifera and Cladocera; sampling was carried out on two dates: 2 March 1999, in the rainy season, and 25 August 1999, in the dry season. Seventy-nine rotifer taxa, 30 cladoceran taxa, and 6 copepod taxa were found. Comparing the species identified in the present study with those recorded by other authors for several water bodies in Mato Grosso and Mato Grosso do Sul states, it was found that 9 species of Cladocera, 2 of Copepoda, and 14 of Rotifera are new records for the region. The most abundant rotifer species were Keratella cochlearis, Brachionus angularis, Polyarthra vulgaris, and Keratella americana. Moina minuta and Bosminopsis deitersi were dominant among the cladocerans, and Notodiaptomus transitans and N. devoyorum among the copepods. Comparing both lakes, the greatest species richness of both Rotifera and Cladocera was observed in Lake Souza Lima, during the rainy season. This is probably linked to the fact that the littoral region of this lake is densely colonized by macrophytes. The lake also has better environmental conditions since it does not receive domestic sewage inputs, as does Lake Parque Atalaia. The diversity of the Rotifera was markedly low in Lake Parque Atalaia, during the dry season, again perhaps linked domestic sewage input found in this water body.
Effects of surgically implanted dummy transmitters on the South American catfish Jundiá (Rhamdia quelen)
Authors: Schulz U. H.
Published: April 2005

High water temperatures and low water quality may negatively influence wound healing, growth and transmitter retention in radio-tagged fish of tropical and subtropical water bodies which in turn may hamper radio tracking studies. For a period of 90 days, we compared growth of an experimental group of ten Rhamdia quelen, which were submitted to intraperitoneal dummy transmitter implantation, with that of a control group. Additionally, wound healing and transmitter expulsion were observed in the experimental group. Water temperature varied between 24°C and 30°C during the study. Experimental group and control fish decreased in body weight during the investigation period, but the differences between the mean individual weight loss in both groups were not significant (Student t-test, p = 0.64). Wound healing in experiment group fish was advanced after 14 days, while after 70 days eight out of ten incision wounds were closed and cicatrized. One fish had its dummy transmitter expulsed through the ventral body wall. After 90 days two more fish had the dummies expulsed, one through the ventral body wall and the other through the antenna exit. One experimental group fish died with visible signs of infection. The results encourage the use of surgically implanted radio transmitters for long-term tagging studies at high water temperatures.
First occurrence of parasitoid Spalangia endius (Walker) (Hymenoptera: Pteromalidae) in pupae of Zaprionus indianus Gupta (Diptera: Drosophilidae) in Brazil
Authors: Marchiori C. H. , Silva C. G.
Published: April 2005

This paper reports the first occurrence of the parasitoid Spalangia endius collected in pupae of Zaprionus indianus using traps with fruit bait. The experiment was carried out at the University of Lavras in Lavras, Minas Gerais, Brazil, from November to December, 2001. A total of 4 Spalangia endius specimens were obtained from 105 Zaprionus indianus pupae. The overall prevalence of parasitism was 3.8%.
Spatial and temporal distribution of ''curvina'' larvae (Plagioscion squamosissimus HECKEL, 1840) and its relationship to some environmental variables in the upper Paraná River floodplain, Brazil
Authors: Baumgartner M. S. T. , Nakatini K. , Baumgartner G. , Makrakis M. C.
Published: April 2005

With the objective of studying the spatial and temporal distribution of ''curvina'' Plagioscion squamosissimus larvae and verifying respective spawning sites, monthly sampling was carried out from March 1993 to February 1994 on the Upper Paraná River floodplain. Using a conical-cylindrical plankton net (0.5 mm mesh), samples were taken from the surface of the water bodies, and in the marginal vegetation a strainer and a dragnet (''picaré'') were used. Water samples were collected for environmental variable analysis (temperature, dissolved oxygen, water pH, and electrical conductivity). Water level data were obtained from hydrometric stations. High average density of larvae was found from December 1993 to February 1994 due to high temperature and water level. The Baía sub-area was shown to be the most important in the larvae catch, probably due to its semi-lotic characteristics. Larvae size distribution was shown to be more frequent in the 4.0 mm standard length class, indicating that the sampling stations were next to the spawning sites.
Thermal evidence of the invasion of a stingless bee nest by a mammal
Authors: Hilário S. D. , Imperatriz-Fonseca V. L.
Published: April 2005

Melipona bicolor, an inhabitant of the Atlantic Rainforest, nidifies in hollows of live or dead trees. In order to study thermoregulation of a nest of this species, a temperature data logger was installed inside a hollow tree. After this, an intruder dug a hole, invaded the nest, and probably consumed its honey, pollen and bees, having remained there during three days. Thermal evidence and its behavior allowed the delimitation of a small number of suspects, wich we analized here. The intruder was a small mammal, predominantly nocturnal, that takes shelter in burrows, probably the yellow armadillo (Euphractus sexcinctus). Other evidence, if collected immediately after invasion, could precisely indicate precisely the species.