Two new mermithidis (Nematoda: Mermithidae) parasites of Simulium wolffhuegeli Roubaud and S. jujuyense (Paterson & Shannon) (Diptera: Simuliidae) in Argentina

Two new species of mermithids (Nematoda: Mermithidae), Gastromermis doloresi n. sp. a parasite of Simulium wolffhuegeli Roubaud and Hydromermis doloresi n. sp. a parasite of S. jujuyense (Paterson & Shannon) from Córdoba, Argentina, are described and illustrated. G. doloresi n. sp. is characterized by having medium sized, pear-shaped and oval amphids, eight hypodermal chords all around the body, cylindrical S-shaped vagina, single long spicule 528 [mi]m, whith teh sculpture tip, three rows of genital papillae in which the middle row contains 17 pre-anal and 9 post-anal papillae, and lateral rows contain 18 papillae. Hydromermis doloresi n. sp. can be distinghished by the following: medium sized, pear-shaped amphids, eight hypodermal chords, a cylindrical, S-shaped vagina, one short curved spicule with sculpture and genital papillae in three rows. The medium ventral row of papillae has 4 double and 9 single pre-anal papillae and 3 double and 6 single port-anal papillae, lateral rows have 18 single papillae each.

Two new neotropical species of Monohelea Kieffer and Downeshelea Wirth & Grogan (Diptera: Ceratipogonidae)

Two new Neotropical predaceous midges are described and illustrated, Downeshelea charrua from Uruguay, and Monohelea bidenata from Argentina. The first species is described from female and male specimens; only one male is know from the second.

Differential species-specific ectoparasitic mite intensities in two intimately coexisting sibling bat species: resource-mediated host attractiveness or parasite specialization?

1. The mechanisms underlying host choice strategies by parasites remain poorly understood. We address two main questions: (i) do parasites prefer vulnerable or well-fed hosts, and (ii) to what extent is a parasite species specialized towards a given host species? 2. To answer these questions, we investigated, both in the field and in the lab, a host-parasite system comprising one ectoparasitic mite (Spinturnix myoti) and its major hosts, two sibling species of bats (Myotis myotis and M blythii), which coexist intimately in colonial nursery roosts. We exploited the close physical associations between host species in colonial roosts as well as naturally occurring annual variation in food abundance to investigate the relationships between parasite intensities and (i) host species and (ii) individual nutritional status. 3. Although horizontal transmission of parasites was facilitated by the intimate aggregation of bats within their colonial clusters, we found significant interspecific differences in degree of infestation throughout the 6 years of the study, with M. myotis always more heavily parasitized than M. blythii. This pattern was replicated in a laboratory experiment in which any species-specific resistance induced by exploitation of different trophic niches in nature was removed. 4. Within both host species, S. myoti showed a clear preference for individuals with higher nutritional status. In years with high resource abundance, both bat hosts harboured more parasites than in low-resource years, although the relative difference in parasite burden across species was maintained. This pattern of host choice was also replicated in the laboratory. When offered a choice, parasites always colonized better-fed individuals. 5. These results show first that host specialization in our study system occurred. Second, immediate parasite choice clearly operated towards the selection of hosts in good nutritional state.

Proterodiplostome Parasites (Digenea, Proterodiplostomidae) of the Caiman, Caiman crocodilus yacare (Reptilia, Crocodylia) in the Pantanal mato-Grossense, Brazil, with the description of two new species

Two new species are described from the caiman. Caiman crocodilus yacare. Proterodiplostomum breve n. sp. differs from all other species in the genus by the following chacacteristics: (1) the paraprostate gland is shorter and club-shaped; (2) the genital cone is, in average, eight times longer than that of P. medusae; (3) the genital atrium is larger and without pseudosuckers; (4) the oral sucker and pharynx are longer; and (5) there are larger numbers of papillae surrounding the tribocytic organ (40) against 20 in P. longum, 16 in p. tumidilum, 8 in P. ophidum, and 16-18 in P. medusae. Proterodiplostomum globulare n. sp. differs from all the other species in the fenus by the following characteristics: (1) from P. tumidilum, P. lomgum, P. medusae, and P. breve n. sp. for the absense of pseudosuckers or muscular bunches in the inferior wall of the genital atrium; (2) the shape of the paraprostate gland, which is globular and not cylindrical as in P. longum, P. tumidilum, P. medusae, and P. ophidum; (3) the size of the tribocytic organ 201-407 long, 183-495 wide, while is 138-270 long, 102-292 wide in P. medusae, and 138-270 long, 255 wide in P. ophidum; (4) the number of papillae in the tribocytic organ (18-20) in P. globulare and 16-18 in P. medusae, and 8 in P. ophidum. Specimens belonging to six other species of proterodiplostomes are recorded for the first time infecting the caiman, C. c. yacare in the Pantanal Mato-grossense, Brazil, namely: Proterodiplostomum medusae, P. tumidilum, Cystodiplostomum hollyi, Prolecithodiplostomum constrictum, Paradiplostomum abbreviatum, and Herpetodiplostomum caimancola.

Análisis de una iniciativa estudiantil de investigación surgida en Criptogamia, una asignatura optativa de segundo ciclo de Biología = Analysis of a students’ research initiative originating in Cryptogamy, an elective course in the last two years of the Biology degree

Presentamos una experiencia exitosa de aprendizaje que partió de Criptogamia (asignatura optativa de segundo ciclo de Biología), que dio lugar a un proyecto de investigación gestionado por los propios alumnos. La iniciativa se consolidó estableciendo una Asociación de Estudiantes centrada en investigación y divulgación. En poco tiempo, los participantes han presentado comunicaciones científicas, y organizado actividades dirigidas a diversos públicos, dentro y fuera de la comunidad universitaria. Actualmente se plantea una colaboración multidisciplinar con otros organismos de investigación y la extensión de su ámbito de estudio. Abordamos su incidencia en el aprendizaje en varios aspectos: científico (técnicas específicas, rigor, búsqueda de información e interpretación de resultados), comunicativo (estructuración y presentación de la información obtenida, para diversos públicos), y organizativo, incluyendo el trabajo en equipo. Aunque de carácter espontáneo, esta experiencia muestra rasgos evaluables en cuanto a sus posibilidades para otras asignaturas. Analizamos las características y planteamiento de esta optativa, el perfil de sus alumnos, y el contexto universitario que la acoge. Detectamos como factores principales los aspectos participativos de la asignatura, la cohesión del grupo, el carácter voluntario de la implicación, los beneficios percibidos por los estudiantes, y la disponibilidad de recursos humanos (supervisión) y materiales (equipamiento y subvenciones).

Simian malaria at two sites in the Brazilian Amazon: I-The infection rates of Plasmodium brasilianum in non-human primates

The parasite that causes simian malaria in the Brazilian Amazon, Plasmodium brasilianum, is infective to man. In this region, where humans live within and in close proximity to the forest, it was suspected that this parasite could be the cause of a zoonosis. A study was performed in the areas surrounding two hydroelectric plants in the Amazon, Balbina and Samuel, aiming at determining the zoonotic potential of this parasite. P. brasilianum was detected in, respectively, 15.8% and 9.9% of 126 and 252 primates belonging to seven and eight species examined from Balbina and Samuel. The highest malaria infection rates were found among the red-howler monkey Alouatta seniculus straminea (32.3%), the bearded-saki Chiropotes satanas chiropotes (50%) and the spider-monkey Ateles paniscus paniscus (2[1+]) from Balbina and in the squirrel-monkey Saimiri ustus (21%) and the black-faced-spider-monkey Ateles paniscus chamek (28.6%) from Samuel.

Effects of increased drought and selective thinning on growth and resprouting of two coexisting Mediterranean oaks with contrasting leaf habit (Quercus ilex and Quercus cerrioides)

According to the IPCC (2007), the Mediterranean basin is expected to suffer important changes in temperature and precipitation in the next few decades, leading the climate warmer and dryer. Therefore, it is necessary to determine the possible effects of increased drought on species with different structural and physiological traits, to be able to predict possible changes in the structure and composition of Mediterranean forests. Moreover, it will be necessary to assess whether traditional management practices can mitigate the effects of climate change on these forests. The main aim of this study has been to analyze the effects of increased drought on the mortality, growth and resprouting patterns of two co-occurring Mediterranean oak species with contrasting leaf habit (the evergreen Quercus ilex and the winter-deciduous Quercus cerrioides), and to assess the effects of selective thinning on their response to increased drought. Our results show a differential effect of increased drought between species: no differences were observed in the growth of Q. ilex while Q. cerrioides reduced its growth under increased drought conditions. Selective thinning reduced the negative effects of increased drought on tree growth, although this beneficial effect tended to decrease during the experiment. Our results show that increasing aridity in Mediterranean areas can be a constraining factor for deciduous oaks, thus potentially causing their decline in mixed forests and favouring their substitution by the evergreen congeneric species. However, as seen in this study, management can strongly encourage growth both for deciduous and evergreen species, thus reversing the effects of increased water stress on Mediterranean coppices.

Monogenean parasitic on marine fishes from Perú and Chile: three new species and two new combinations

Five species of monogeneans collected from marine fishes of the Pacific coast of Chile and Perú were studied. Three of them are new species: Interniloculus chilensis n. sp. (Capsalidae), Neoheterobothrium insalaris n. sp. (Diclidophoridae) and Loxura peruensis n. sp. (Axinidae) parasitic on Sebastes capensis (Scorpaenidae), Paralichthys sp. (Bothiidae) and Belone scapularis (Belonidae), respectively. Two new combinations are proposed, Intracotyle neghmei (Microcotylidae) for Neobivagina neghmei Villalba, 1987 and Hargicotlyle conceptionensis (Diclidophoridae) for Choricotyle conceptionensis Villalba, 1987.

Two new species of the subgenus Peytonulus of Sabethes (Diptera: Culicidae) from Colombia

The adults and male genitalia of two new species of Sabethes subgenus Peytonulus are described from Colombia. The male genitalia are illustrated and the species are distinguished from one another and other members of the subgenus.

Acute respiratory infections in children living in two low income communities of Rio de Janeiro, Brazil

Community studies of non-hospitalized children are essential to obtain a more thorough understanding of acute respiratory infections (ARI) and provide important information for public health authorities. This study identified a total ARI incidence rate (IR) of 4.5 per 100 child-weeks at risk and 0.78 for lower respiratory tract infections (LRI). Disease duration averaged less than one week and produced a total time ill with ARI of 5.8% and for LRI 1.2%. No clear seasonal variation was observed, the sex-specific IR showed a higher proportion of boys becoming ill with ARI and LRI and the peak age-specific IR occurred in infants of 6-11 months. Correlation with risk factors of the child (breastfeeding, vaccination, diarrheal disease, undernourishment) and the environment (crowding, living conditions, maternal age and education) showed marginal increases in the rate ratios, making it difficult to propose clear-cuts targets for action to lower the ARI and LRI morbidity. The importance of an integral maternal-child health care program and public education in the early recognition of LRI is discussed.

Neotropical Monogenoidea. 23. Two new species of Gyrodactylus (Gyrodactylidae) from a Cichlid and an Erythrinid fish of Southeastern Brazil

Two new species of Gyrodactylus Nordmann, 1832 (Platyhelminthes, Monogenoidea) are described from fishes collected from southeastern Brazil. Gyrodactylus geophagensis n. sp. was collected from the body surface of the "cará", Geophagus brasiliensis (Quoy and Gaimard, 1824) (Cichlidae), from the Rio da Guarda, state of Rio de Janeiro; its major diagnostic features are the morphology of the anchor with a short, truncate superficial root and the shape of the hooks - with a long, delicate shaft. Gyrodactylus trairae n. sp. parasitizes the body surface of the "traíra", Hoplias aff. malabaricus (Bloch, 1794) (Erythrinidae), from the rio Guandu, state of Rio de Janeiro and can be easily differentiated from other species of the genus by having a thin, dorsal bridge, connecting the superficial bar with the spathulated shield. These are the first species of Gyrodactylus formally reported from Brazil. Presently, 26 species of Gyrodactylidae are known from freshwater fishes in the neotropical region; a list of these species is provided.