RESUMO As amostras de penas foram obtidas das seguintes aves da ordem Psittaciformes: Amazona amazonica, Amazona aestiva, Aratinga jandaya, Brotogeris spp., Ara ararauna e Ara chloropterus, totalizando 37 aves, alojadas no Centro de Triagem de Animais Silvestres do Maranhão, São Luís, Brasil. Colheram-se quatro penas de cada uma das regiões: cabeça, dorso, asas, ventre/peito, coxas e cauda/crisso. Verificou-se a presença de ácaros em 17 aves (45,94%). Foram identificados ácaros Astigmata, pertencentes aos gêneros Fainalges (Xolalgidae), Chiasmalges (Psoroptoididae) e Tanyaralichus (Pterolichidae), sendo o maior coeficiente de dominância correspondente ao ácaro Fainalges sp. (CD= 96,29). Chiasmalges sp. foi obtido apenas de Ara chloropterus, e Tanyaralichus foi encontrado em A. amazônica. O gênero Fainalges foi obtido de todas as espécies de Psittaciformes estudadas, exceto em A. ararauna. Na avaliação da densidade de ácaros por região do corpo, verificou-se diferença estatística entre regiões dorsal e asas (P= 0,041), dorsal e coxas (P= 0,02), asas e caudal (P=0,002), ventral e caudal (P= 0,031) e coxas e caudal (P= 0,001). Variações morfológicas observadas em Fainalges spp., sugerem a existência de três espécies provavelmente ainda não descritas. Este é o primeiro registro do gênero Tanyaralichus no Brasil.

ABSTRACT Feather samples were obtained from the following Psittaciformes birds: Amazona amazonica, Amazona aestiva, Aratinga jandaya, Brotogeris spp., Ara ararauna and Ara chloropterus (total of 37 individuals). These birds were housed at the Wild Animal Screening Center of Maranhão, São Luís, Brazil. Four feathers were taken from the following regions: head, back, wings, belly/breast, thighs, and tail/covert. Mites were found on 17 birds (45.94%). Astigmatid mites belonging to the genera Fainalges (Xolalgidae), Chiasmalges (Psoroptoididae) and Tanyaralichus (Pterolichidae) were identified. The highest dominance coefficient was for the mite Fainalges sp. (DC= 96.29). Chiasmalges sp. was obtained only from Ara chloropterus, and Tanyaralichus was found in A. aestiva. The genus Fainalges was obtained from all the species of Psittaciformes studied, except for A. ararauna. In evaluating mite density according to body region, statistical differences were found between the back and wing regions (P= 0.041), back and thighs (P= 0.02), wings and tail (P= 0.002), belly and tail (P= 0.031) and thighs and tail (P= 0.001). The morphological variations observed in Fainalges spp. suggested the existence of three species that probably have not been described yet. This was the first record of the genus Tanyaralichus in Brazil.

ABSTRACT The aim of this study was to verify the parasitologycal aspects of fish (Hoplias malabaricus), coming from São Bento city, Maranhão state. For this, 70 fish were used, verifying the parasitism indexes and coefficients. For the parasitological results nematodeos were identified, with zoonotical potential of the Contracaecum spp, Pseudoterranova spp, Eustrongylides spp; monogenetics Gyrodactirus spp, Dactylogirus spp and larva Acanthella of Acanthocephalo. Of the 70 (100%) fishes, 64 (91.4%) were sponged, with prevalence of 82.8% (58) for the nematodeo Contracaecum spp, 65.7% (46), Pseudoterranova spp, 7.1% (5), Eustrongylides spp, 71.4% (50), monogenetics and larva Acanthella of Acantocephalo, respectively. A maior amplitude de intensidade (1-30), coeficiente de variação foi verificado para o nematódeo Pseudoterranova spp., a intensidade média (7,3), índice de abundância (6,7), coeficiente de dominância (36,4) foi ao Contacaecum spp., todos os parasitos estavam no mesentério da cavidade abdominal, encistados em forma larval.The largest intensity width (1-30), variation coefficient was verified for the nematodeo Pseudoterranova spp, the medium intensity (7,3), abundance index (6,7), dominance coefficient (36,4) it went to the Contacaecum spp, all of the parasites were in the mesenterio of the abdominal cavity, encysted in larval form. The results show that fish from this region presented unsatisfactory sanitary conditions in parasitological aspect and can expose consumers to the risks of foodborne illnesses.

In this work we describe briefly the stratigraphy and the structure of the Andes in the transition zone between the Aconcagua and Malargüe fold and thrust belts. The outcrops are a Permotriasic volcanic acid basement, Mesozoic sediments of the Cuenca Neuquina and Neogene volcanic rocks and continental deposits. Structuraly we distinguish from west to east four segments: a tectonic inversion zone, a tight folds zone, a central or imbrication zone, and the Carrizalito anticlinal. Two structural sections were built using field data collected from the thight folds and imbrication zones and the from western flank of the Carrizalito anticlinal, that describe the structures in the area. Regional lineaments with northwest trends, could be acting as transfer zones. It can be recognize two or three deformational pulses according to the relative ages between the structures and the uplift of the Cordillera Frontal. If the cordon del Carrizalito was a basement high we propose two deformational pulses, the first one of thin skinned type and the second one responsible of the uplift of the Frontal Cordillera, tilting the previously deformed sequence. If the uplift of the Carrizalito anticlinal worked as a sticking point of the fold and thrust belt, a third deformational episode with out-ofsequence faults could be recognized.

En el presente trabajo se describe brevemente la estratigrafía y la estructura de los Andes en la zona de transición entre las fajas plegadas y corridas del Aconcagua y Malargüe. Las rocas aflorantes corresponden a un basamento volcánico acido permotriásico, sedimentitas mesozoicas de la cuenca neuquina y efusiones volcánicas y depósitos continentales neógenos. Estructuralmente se reconocen de oeste a este, cuatro segmentos denominados: zona de inversión tectónica, zona de pliegues apretados, zona central o de imbricación y anticlinal del Carrizalito. Se construyeron dos secciones estructurales que se ajustan a los datos de campo recogidos en las zonas de imbricación, de pliegues apretados y del flanco dorsal del anticlinal del Carrizalito, que permitieron describir las estructuras presentes en el área. Lineamientos regionales de orientación noroeste-sureste podrían estar actuando como zonas de transferencia de rechazos. Pueden reconocerse dos o tres pulsos deformacionales según se considere la edad relativa de las estructuras respecto al levantamiento de la Cordillera Frontal. Para el caso en que el cordón del Carrizalito haya actuado como un alto de basamento se proponen dos pulsos, uno de piel fina y otro posterior que levanta a la Cordillera Frontal basculando la secuencia previamente deformada. Si en cambio la estructuración del anticlinal del Carrizalito hizo que este se comporte como punto de fijación (sticking point) podria sumarse un tercer episodio deformacional con corrimientos fuera de secuencia.