Parasite infracommunities of Leporinus friderici: A comparison of three tributaries of the Jurumirim Reservoir in southeastern Brazil

ABSTRACT The degradation and homogenization of natural habitats is considered a major cause of biotic homogenization. Many studies have been undertaken on the effects of dams on aquatic wildlife, in particular fish assemblages. But how do dams affect the parasitic fauna of such fish? The aim of the present study was to examine parasitic similarity, comparing the diversity and structure of parasite communities of Leporinus friderici (Characiformes, Anostomidae) in three upstream tributaries under the influence of the Jurumirim Dam on the Upper Paranapanema River in southeastern Brazil. The present study did not find any significant differences in parasite communities among populations of L. friderici in the three upstream tributaries. This result highlights that dams promote and facilitate the dispersal of organisms between localities, and therefore the spatial homogenization of parasite communities. Overall, the results suggest that fish parasite assemblages can provide suitable data for evaluating biotic homogenization caused by dams.

A new species of Tereancistrum (Monogenea, Dactylogyridae) from the gills of three Leporinus species (Characiformes, Anostomidae) and a revised description of Tereancistrum parvus

ABSTRACT The present study describes Tereancistrum flabellum n. sp. (Dactylogyridae, Ancyrocephalinae) from the gills of the anostomid fishes Leporinus friderici, Leporinus amblyrhynchus and Leporinus elongatus from two freshwater ecosystems in the south east of Brazil. This new species is mainly characterized by the morphology of the copulatory complex (such as the MCO base formed by two fan-shaped structures, and accessory piece flattened, curved, rigid and channeled), a dorsal anchor with a well-developed superficial and inconspicuous deep root, and the shape of the accessory anchor sclerite with small spathulate termination. Tereancistrum flabellum n. sp. is the first record of a dactylogyrid from L. amblyrhynchus. The description of Tereancistrum parvus is also emended to correct and complement previous descriptions and the species is reported for the first time in Schizodon nasutus.

Parasitic communities of Hoplosternum littorale (Hancock, 1828) as indicators of environmental impact

ABSTRACT The parasites are indicative of several biological aspects of their hosts, including their diet, migration, recruitment and phylogeny, but they can also be direct indicators of the environmental quality. Hoplosternum littorale is a fish that has a high commercial value in some South American countries. The fishes were collected from January to July 2012, in two locations of the Peixe River in the municipality of Anhembi, State of São Paulo, Brazil, which had different environmental and limnological characteristics (river mouth and Lagoa Cabeça de Boi). An amount of 30 fish specimens were captured in each location for the analysis of their parasitic fauna. Nine species of metazoan parasites were collected. Both Brillouin`s diversity index and Margalef`s richness index were greater in the Lagoa Cabeça de Boi. The ratio of heteroxenous and monoxenous parasite species richness (SH/SM) was higher in the Lagoa Cabeça de Boi. The results of the physicochemical analysis of the water showed that the mouth of the Peixe River can be considered an area that suffers more from anthropogenic actions than the Lagoa da Cabeça de Boi. Proteocephalus sp., Gyrodactylus sp., Scleroductus sp. and Capillaria (Neocapillaria) pterophylli are being registered for the first time in this host.

First report of Strongyloides sp. (Nematoda, Strongyloididae) in Leopardus tigrinus (Carnivora: Felidae) in the municipality of Botucatu, State of São Paulo, Brazil / Primeiro relato de Strongyloides sp. (Nematoda, Strongyloididae) em Leopardus tigrinus (Carnivora: Felidae) do município de Botucatu, Estado de São Paulo, Brasil

The present study reports the first case of infection by Strongyloides sp. in Leopardus tigrinus in the municipality of Botucatu, State of São Paulo, Brazil. Feces of the infected L. tigrinus specimen were cultivated in sterilized equine feces and a cat (Felis catus domesticus) was experimentally infected with three thousand infective L3 subcutaneous route, in order to identify the Strongyloides species involved in the parasitism. Parthenogenetic females recovered from the experimental animals were analyzed but comparison between the biometric data found and the data in the literature did not enable identification of the species. This is the first report on the occurrence of Strongyloides sp. in L. tigrinus.

O presente estudo reporta o primeiro caso de infecção por Strongyloides sp. em Leopardus tigrinus no município de Botucatu, Estado de São Paulo, Brasil. Fezes do exemplar parasitado de L. tigrinus foram cultivadas em fezes eqüinas esterilizadas e foi realizada infecção experimental em gato (Felis catus domesticus) com três mil larvas L3 infectantes por via subcutânea, para a identificação da espécie de Strongyloides envolvida no parasitismo. As fêmeas partenogenéticas obtidas do animal experimental foram analisadas porém a comparação dos dados biométricos encontrados com os dados da literatura não permitiu a identificação da espécie. Este é o primeiro relato sobre a ocorrência de Strongyloides sp. Em L. tigrinus.

Hemoparasites of the genus Trypanosoma (Kinetoplastida: Trypanosomatidae) and hemogregarines in Anurans of the São Paulo and Mato Grosso do Sul States - Brazil

Wild animals are exposed to numerous pathogens, including hemoparasites. The Trypanosoma and hemogregarinegroup are frequently reported as parasites in anurans (frogs, tree frogs and toads). The identification of these hemoparasites is usually made through stage observation of their morphology in the peripheral blood of the host. There areno studies, however, based on the biological cycle of these hemoparasites. The objective of the present study was toevaluate the presence of hemogregarines and Trypanosoma spp. in anurans captured in the States of São Paulo andMato Grosso do Sul- Brazil and to perform the morphological and morphometric characterization of these hemoparasites. The species of anurans examined were: Dendropsophus nanus, D. minutus, Leptodactylus chaquensis L. podicipinus, L. labyrinthicus, L. fuscus, Bufo granulosus, B. schneideri, Phyllomedusa hypocondrialis, Trachicephalus venulosus, Scinax fuscovarius and Hypsiboas albopunctatus. Of the total of 40 animals studied, four (10 percent)were positive for hemogregarines and eight (20 percent) were positive for Trypanosoma spp. Hemogregarine gamontsshowed variable morphology and, in addition to intraerythrocytic forms, extraerythrocytic forms were also observed.Extremely different forms of Trypanosoma were observed, as described in the literature, with the broad and oval forms being the most common.

Os animais silvestres estão expostos a inúmeros patógenos,dentre eles estão os hemoparasitas. Podem-se destacar espécies do gênero Trypanosoma e do grupo das hemogregarinas,que ocorrem com freqüência parasitando anuros (rãs, pererecas e sapos). Normalmente, a descrição destes hemoparasitas é feita através da morfologia dos estágios observados nosangue periférico do hospedeiro e as pesquisas sobre o ciclobiológico desses hemoparasitas são escassas. Os objetivos dopresente estudo foram avaliar a presença de hemogregarinas eTrypanosoma spp. em anuros capturados nos Estados de São Paulo e Mato Grosso do Sul e fazer a caracterização morfológica e morfométrica dos seus hemoparasitas. As espécies deanuros examinadas foram: Dendropsophus nanus, D. minutus, Leptodactylus chaquensis, L. podicipinus, L. labyrinthicus, L. fuscus, Bufo granulosus, B. schneideri, Phyllomedusahypocondrialis, Trachicephalus venulosus, Scinax fuscovarius e Hypsiboas albopunctatus. Dos 40 animais estudados, foramencontrados quatro (10 por cento) positivos para hemogregarinas e oito(20 por cento) positivos para Trypanosoma spp. Foram observadosgamontes de hemogregarinas com morfologia variável e, alémdas formas intraeritrocíticas, também foram observados gamontes fora das hemácias. As formas de Trypanosoma encontradas eram muito polimórficas, conforme é descrito na literatura, sendo na sua maioria, larga e oval.

Morphometric study of the midgut epithelium in larvae of Diatraea saccharalis Fabricius (Lepidoptera: Pyralidae) / Estudo morfométrico do epitélio do intestino médio em larvas de Diatraea saccharalis Fabricius (Lepidoptera: Pyralidae)

A larva de Diatraea saccharalis Fabricius (broca-da-cana) tem grande interesse econômico, pois afeta o cultivo e aproveitamento industrial da cana-de-açúcar. Entretanto, poucos são os estudos sobre a morfologia interna desse inseto. O objetivo deste trabalho foi estudar, morfometricamente, o seu epitélio intestinal, ao longo de seu comprimento, visando caracterizar regiões estruturalmente diferentes. O intestino médio de larvas no último instar foi subdividido em três regiões: proximal, mediana e distal e os fragmentos foram processados para observação em microscopia de luz. Os cortes histológicos foram analisados em sistema computadorizado de análise de imagens para medir comprimento, largura e área do epitélio, das diferentes células epiteliais, dos seus respectivos núcleos e do lúmen intestinal. Os dados obtidos foram submetidos ao teste estatístico de Kruskal-Wallis e à análise multivariada. Nossos resultados mostraram que o intestino médio apresentou-se constituído, morfometricamente, por duas diferentes regiões, proximal e distal; a região mediana apresentou valores coincidentes tanto com a região proximal quanto com a distal, sugerindo ser região intermediária. As células epiteliais (colunares, caliciformes e regenerativas), quando avaliadas pela análise estatística multivariada, não apresentaram diferença morfométrica nas diferentes regiões do intestino médio. Entretanto, a análise de variância, realizada para variáveis isoladas, mostrou que as células regenerativas apresentaram maior variabilidade morfométrica.

The sugarcane borer, Diatraea saccharalis Fabricius, has great economical interest as it affects the culture and industrial use of the sugarcane. However, there are few studies concerning the internal morphology of this insect. This work aims to study morphometrically the midgut and the epithelium along their lenght, trying to characterize different regions. Midgut of last instar larvae wasdivided in three regions: anterior, middle and posterior, and the fragments were processed for light microscopic observation. Histological sections were analyzed in a computerized system concerning the length, width and area of the epithelium, their cells, and the midgut lumen. The obtained data werestatistically analyzed by the Kruskal-Wallis test and by multivariate analysis. Our results showed that the midgut has two different regions, the anterior and the posterior; the middle region presents values that are coincident with the ones of either the anterior and the posterior portions, suggesting that thereis an intermediate region between the other two ones. The epithelial cells (columnar, goblet and regenerative cells), when evaluated by multivariate analysis, do not present significant morphometric differences in the different midgut regions. However, the analysis of variance for separate variables show that the regenerative cells present wide morphometric variability along the midgut.