Padrões ontogenéticos das Esterases, Leucina Aminopeptidase e X-Glicerofosfato Desidrogenase em Anopheles (Nyssorhynchus) Albitarsis lynch-arribálzaga, 1878 (Diptera: Culicidae)

Modificações na expressão gênica foram observadas nos sistemas esterase, leucina aminopeptidase e x-glicerofosfato desidrogenase, durante o desenvolvimento ontogenético de Anopheles albitarsis. A esterase revelou quatro regiões de atividade, sendo a esterase 1 detectada apenas em larvas de 4º estádio velhas e em pupas, as esterases 2 e 4 foram presentes durante todo o desenvolvimento, e a esterase 3 revelou-se praticamente apenas em larvas e raríssimas vezes em pupas. Também foram observadas quatro regiões de atividade na leucina aminopeptidase, durante a ontogenia. As LAP1 c LAP2 foram características de larvas, a LAP3 esteve presente somente em pupas e adultos e a LAP4 foi detectada nos três diferentes estágios. Uma única região foi observada para a x-glicerofosfato desidrogenase e a intensidade de sua atividade cresce à medida que se aproxima o estágio adulto.

Cephalopoda as prey of juvenile Southern elephant seals at Isla 25 de Mayo/King George, South Shetland Islands

The aim of the present study was to enhance the knowledge of the feeding habits of the juvenile component of the population of Southern elephant seals [Mirounga leonina (Linnaeus, 1758)] from Isla 25 de Mayo, South Shetland Islands, age class whose diet information is scarce. A total of 60 individuals were stomach lavaged in the spring - summer seasons of three consecutive years (2003, 2004 and 2005) of which 53.3 % (n = 32) presented food remnants. The Antarctic glacial squid Psychroteuthis glacialis Thiele, 1921 was the dominant prey taxon in terms of frequency of occurrence (68.7%), numerical abundance (60.1%) and biomass (51.5%), contributing 84.1% to the total relative importance index. Other squid prey species of importance were Slosarczykovia circumantartica Lipinski, 2001 in terms of occurrence (37.5%) and numerical abundance (14%) and Moroteuthis knipovitchi Filippova, 1972 in terms of biomass (16%). All identified cephalopod prey taxa are distributed south of the Antarctic Polar Front, except for the squid Martialia hyadesi Rochebrune & Mabille, 1889 which has a circumpolar distribution associated to the Polar Frontal Zone. No significant differences in the sizes of P. glacialis preyed upon by elephant seals were found between sexes and years. However, significant interannual differences were found in the taxonomical composition of their diet. This would be associated with temporal changes in food availability at the foraging areas of seals, which in turn may have been influenced by changes in oceanographic conditions as a result of the El Niño Southern Oscillation (ENSO) phenomenon that occurred during part of the study period. Furthermore, a differential response of males and females to this temporal variation was observed, with the former being also associated to a predation on octopods. This would suggest a sexual segregation in foraging habits of this species from the early stages of its life cycle.

Contribuição ao conhecimento dos Bulimulidae: cochlorina aurisleporis (Bruguiére, 1792) (Gastropoda, Pulmonata)

Die Autoren bearbeiten in der vorliegenden Arbeit die bulimuliden Pulmonaten Cochlorina aurisleporis (Bruguiére, 1792), wobei sie insbesondere auf die anatomischen und histologischen Verhaeltnisse des Geschlechtsapparates eingehen und Schale, Kiefer und Lunge mit in die Betrachtung einbeziehen, um die Charaktere der Art anatomisch zu festigen.

A morphological, isoenzymatic and behavioural study of ten populations of Anopheles(Nyssorhynchus) albitarsis Lynch-Arribalzaga, 1878 (Diptera: culicidae) including from the type-locality - Baradero, Argentina

Anopheles (Nyssorhynchus) albitarsis Lynch-Arribalzaga, 1878 shows morphological and behavioural variations which results in it being sometimes considered as a major malaria vector and at other times as playing no important role in epidemiology. With the aim of clarifying the taxonomy of the species, comparative morphological and isoenzymatic studies were made in populations from the type-locality, Baradero, Argentina and from 9 different localities inBrazil. Morphological studies consisted of the observation of eggs in scanning electron microscopy, of complete chaetotaxy of larvae and pupae and of the detailed drawing of male and female adults. Only Guajara-Mirim and Rio Branco populations, described previously as Anopheles deaneorum sp.n., showed morphological differences. Isoenzymes were studied using 4th instar larvae homogenate and agarosegel electrophoresis. Eleven enzymatic loci were analyzed. By calculation of Nei's Genetic Distance (D), the populations could be separated into 5 groups: i)Baradero, ii)Marajo, iii)Boa Vista, iv)Angra, Itaguai and Paraipaba and v)Guajara-Mirim and Rio Branco. These groups belong to 2 major clusters called I and II, separated by D = 0.345. In the I cluster are groups i, ii and iii and in II clusteriv and v. In I, D=0.246 separates i and ii from iii, while i is separated by D =0.181 from ii. In II, D = 0.223 between iv and v. Only the population of group vcould be distinguished morphologically from the others, leading to the description of an independent species An. deaneorum.

Tempo de busca e de manuseio de larvas de Chrysoperla externa (Hagen, 1861) (Neuroptera, Chrysopidae) alimentadas com Uroleucon ambrosiae (Thomas, 1878) (Hemiptera, Aphididae)

Searching and handling time of Chrysoperla externa (Hagen, 1861) (Neuroptera, Chrysopidae) larvae fed on Uroleucon ambrosiae (Thomas, 1878) (Hemiptera, Aphididae). The objective of this research was to determine the searching and handling times of three larval instars of C. externa fed on U. ambrosiae at densities of 30, 40 and 50 per vial, with the feeding of the larvae at the preceding instars being U. ambrosiae nymphs or Sitotroga cerealella (Olivier, 1819) eggs. The larvae were maintained at 25 ± 2 ºC, 70 ± 10% RH and a 14-h photophase. A completely randomized design in a 6 x 3 factorial scheme with 12 replicates was adopted. The shortest searching time was found for the 2nd and 3rd instar larvae of C. externa, and this parameter was variable depending on the feeding given to the larvae previously. The handling time was similar for the 1st, 2nd and 3rd instar larvae. The longest searching time was found at an aphid density of 30, as compared to densities of 40 and 50 prey, with which there were no significant differences. Prey density did not have any influence on handling time.

Potencial de alimentação de Chrysoperla externa (Hagen, 1861) (Neuroptera, Chrysopidae) em diferentes densidades de Uroleucon ambrosiae (Thomas, 1878) (Hemiptera, Aphididae)

Feeding potential of Chrysoperla externa (Hagen) (Neuroptera, Chrysopidae) in different densities of Uroleucon ambrosiae (Thomas) (Hemiptera, Aphididae). The feeding potential of 2nd and 3rd instar larvae of Chrysoperla externa (Hagen, 1861) in relation to different densities of 30, 40 and 50 nymphs of Uroleucon ambrosiae (Thomas, 1878) at 3rd and 4th instars was evaluated. The treatments were individualized into 2.5 cm in diameter and 8.5 cm tall flat bottom glass vials and maintained in a controlled environmental chamber at 25±2 ºC temperature, 70±10% RH and 14 h photophase. A completely randomized experimental design with 10 replications was used. The consumption of the prey nymphs by the predator larvae was evaluated after 1, 2, 4, 8, 16 and 24 h from the beginning of the experiment and at every subsequent 24 h period until 2nd instar larvae molted or 3rd instar larvae pupated. Results have shown that for 2nd instar larvae, during the 1 h to 24 h period, there was a decreasing prey consumption at the 30 and 40 prey densities. However an increase in the consumption at the 50 prey density was observed. After this period, C. externa larvae presented a progressive increase on nymphs consumption as a function of the prey density. The same occurred with de 3rd instar predator larvae in all treatments. When daily mean consumption was evaluated the predator/prey ratio was 1:23, 1:27 and 1:33 for 2nd instar larvae and 1:27, 1:33 and 1:41 for 3rd instar larvae at 30, 40 and 50 nymph densities, respectively.

Colonization by mites of glacier-free areas in King George Island, Antarctica

This work aimed to investigate the ratio of colonization by terrestrial mites on ice-free areas created by the ongoing climate-induced melting of Antarctic glaciers. Glacier retreat opens new ice-free areas for the colonization by vegetation and animals. The study was undertaken on the Antarctic Specially Protected Area no. 128 (West Coast of the Admiralty Bay, King George Island, South Shetlands Islands). Transects marked between the Ecology, Baranowski and Windy Glaciers, and a sea shore were used to collect soil samples. Oribatid mites were found only on near-shore areas, on patches of vegetation of more than 30 years of age. The colonization by mite communities is strongly determined by the presence of plants.

O médico George Thomson e os primeiros desenvolvimentos do conceito de gás

The word gas was coined by the "chemical philosopher" Joan Baptista Van Helmont (1579 -- 1644) to name a very broad concept in his chemico-medical system. Eventually, some physicians who followed Helmontian ideas adopted the concept. The present paper aims to analyze the reception of the original idea of gas by an English Helmontian physician, George Thomson (1619 -- 1677). Thomson wrote that the "material cause" of the plague was a gas, and compared it to the "Gas of sulphur". He also related the human archeus to a gas, and explained some observations in the laboratory in terms of production of gases. We observe, however, that Thomson was not as interested as Van Helmont in discussing details about the structure of the matter. Thus, gas did not have the same relevance in Thomson's work as it had in Van Helmont's.