Schistosoma mansoni Sambon, 1907: comparative morphologica studies of some Brazilian strains

The morphology of Schistosoma mansoni adult male worms from three strains which have been maintained in albino mice for several generations, was compared to a strain that has been isolated from the natural host Nectomys squamipes (Rodentia: Muridae) captured in Sumidouro (Rio de Janeiro State) and have been maintained in the same sylvatic rodent under laboratory conditions. Total length of specimens, distance between suckers, the number of testes and extention of testes grouping were the taxonomic characters analysed. The worms recovered from N. squamipes showed expressive differences (p< 0.01) compared to the other strains regarding the considered morphological characters. The strains that were maintained in mice presented statistical differences (p< 0.01) in several characters. Some adult worms besides the normal position of the testes also showed an atypical arrangement of these glands. It can be concluded that the morphology of adult worms may be used to distinguish S. mansoni strains and that morphological changes in adult worms are not induced by successive inoculations of a strain in mice.

Vanamea GEN. NOV. FOR Livoneca symmetricaVAN NAME,1925, (CRUSTACEA, ISOPODA, CYMOTHOIDAE) AND A REDESCRIPTION OF THE SPECIES BASED ON SPECIMENS FROM BRAZILIAN PIRANHAS

Studies of the cymothoid isopod Livoneca symmetricaVan Name, 1925, showed that this species has characters that preclude its inclusion in LivonecaLeach, 1818, or in any other known genus. The species is redescribed on the basis of male and female specimens from the mouth cavities of Amazonian piranhas (Serrasalmus spilopleura(Kner) and S. elongatusKner) and Vanameagen. nov. is proposed for it. The new genus is defined as having: a cephalon that is not immersed in pereonite 1; mandibles that are "foot-shaped" and without incisors, pereopods that are long and unequal in size and shape; a pleon that is not immersed in the pereon; and a pleotelson that is inflated anteriorly and medially.

The genital atrium armature of some Brazilian sand fly females (Diptera: Phlebotominae)

Phlebotomine sand flies are insects of medical importance. Species in the Neotropical region are highly diverse. Some of these species are considered cryptic species because of their morphological similarity between adult females of different species make identification especially difficult. The aim of this study was to analyze and describe the armature in the genital atrium (AGA) of some adult female sand flies, in order to discover new taxonomic characters that make it possible to distinguish between species that would otherwise be treated as cryptic by analysis of the AGA. The AGA of 16 Phlebotomine sand fly species are described. Distinct differences were found in relation to the shape and size of the armature, the presence or absence of spines on the armature, and the shape, size, and grouping patterns of the spines. These characters made it possible to distinguish between the species studied.

Morphology of three Brazilian species of Semiotus (Coleoptera, Elateridae, Semiotinae)

The morphology of Semiotus distinctus (Herbst, 1806), S. intermedius (Herbst, 1806) and S. ligneus (Linnaeus, 1767), including mouthparts and male and female genitalia, is described and illustrated. A comparative analysis of the characters related to the external morphology, mouthparts and male and female genitalia is also included.

Morphometric variability in populations of Palaemonetes spp. (Crustacea, Decapoda, Palaemonidae) from the Peruvian and Brazilian Amazon Basin

Morphometric variability among shrimp populations of the genus Palaemonetes Heller, 1869 from seven lakes (Huanayo and Urcococha, in Peru; Amanã, Mamirauá, Camaleão, Cristalino e Iruçanga, in Brasil) in the Amazon Basin, presumably belonging to Palaemonetes carteri Gordon, 1935 and Palaemonetes ivonicus Holthuis, 1950, were studied. The morphometric studies were carried out from the ratios obtained from the morphometric characters. Multivariated analysis (Principal Components Analysis-PCA, Discriminant Function Analysis and Cluster Analysis) were applied over the ratios. Intra- and interpopulation variations of the rostrum teeth, and the number of spines in the male appendix, were analyzed through descriptive statistics and bivariate analysis (Spearman Rank Correlation test). Results indicated a wide plasticity and overlapping in the studied ratios between populations. The Principal Components Analysis was not able to separate different populations, revealing a large intrapopulation plasticity and strong interpopulation similarity in the studied ratios. Although the Discriminant Functions Analysis was not able to fully discriminate populations, they could be allocated in three subgroups: 1) Cristalino and Iruçanga; 2) Huanayo, Urcococha and Camaleão and 3) Mamirauá and Amanã. The first two groups were morphometrically separated from each other, whereas the third one presented a strong overlap with the former two. The Cluster Analysis confirmed the first two subgroups separation, and indicated that the first and third groups were closely related. Rostrum teeth and number of spines in the appendix masculina showed a large intrapopulation variation and a strong overlapping among the studied populations, regardless of the species.

Revalidation of Acanthagrion cuyabae (Odonata, Coenagrionidae) and description of the female, with a key to the Brazilian species of the viridescens group

Acanthagrion cuyabae Calvert, 1909 was described based on a male from State of Mato Grosso, Brazil. The female of this species was described based on morphological characters of four individuals collected in copula from State of Mato Grosso do Sul, and three other specimens of same locality. Acanthagrion cuyabae is here revalidated based on morphological characters of the female. Illustrated keys to the groups of Acanthagrion Selys, 1876 and species of the viridescens group occurring in Brazil are provided.

Taxonomic revision of doubtful Brazilian freshwater shrimp species of genus Macrobrachium (Decapoda, Palaemonidae)

The freshwater prawns of the genus Macrobrachium Spence Bate, 1868 are widely distributed in rivers of tropical and subtropical regions and represent an interesting group with controversial taxonomy. The morphological characters traditionally used to separate species have shown a high intraspecific variation. Doubts about the status of M. birai Lobão, Melo & Fernandes, 1986, M. holthuisi Genofre & Lobão, 1978 and M. petronioi Melo, Lobão & Fernandes, 1986 have been arisen due to the high resemblance of the former two species with M. olfersi (Wiegmann, 1836), and the latter one with M. potiuna (Müller, 1880). Therefore, we performed a detailed morphological analysis of these species, including new characters not usually used in the species recognition. The present results here with molecular data lead us to conclude that M. birai and M. holthuisi are junior synonyms of M. olfersi, and M. petronioi is a junior synonym of M. potiuna. Considering these synonymies, 17 valid species are now reported for the Brazilian territory.

Morphological Features of Trypanosomes from Squirrel Monkeys from the Brazilian Amazon

A morphometric analysis of blood trypomastigotes identified as Trypanosoma minasense, T. saimirii, and T. rangeli harbored by squirrel monkeys from the Brazilian Amazon was performed. Additionally, morphological and biological comparative analyses were conducted of T. saimirii-like and T. rangeli development forms from haemoculture and xenodiagnosis. Illustrations are given of blood trypomastigotes as well as of developing flagellates in triatomine and axenic culture. Mean values of blood trypomastigotes of T. saimirii differ statistically from those of T. rangeli in only two out of ten morphological characters measured, and ranges overlapped. The developing forms of T. saimrii-like parasites were essentially identical in both xenodiagnosis and haemoculture to those of T. rangeli. Trypanosomes confirmed as T. rangeli were transmitted to mice by the bites of the great majority of triatomines that fed on T. saimirii-like infected monkeys. We conclude that, based on morphology and on the development in triatomine bugs and haemoculture, T. saimirii should not be considered a distinct species. We therefore propose T. saimirii to be a junior synonym of T. rangeli

Fimbriaria fasciolaris and Cloacotaenia megalops (Eucestoda, Hymenolepididae), Cestodes from Brazilian Waterfowl

Two cestode species, Fimbriaria fasciolaris (Pallas, 1781) Frölich, 1802 Cloacotaenia megalops (Nitzsch in Creplin, 1829) Wolffhügel,1938 collected from Anas bahamensis Linné, 1758 and Amazonetta brasiliensis (Gmelin, 1758) in lagoons of the Maricá District, State of Rio de Janeiro, Brazil, are described. This is the first record of F. fasciolaris parasitizing A. bahamensis. The prevalence, intensity of infection, and mean intensity of infection for both species are given. Overdispersion distribution is reported for F. fasciolaris with 535 specimens collected in a single A. bahamensis. A key for the genera in the Fimbriariinae is presented. Anatomical features of F. fasciolaris and C. megalops are discussed.

Differences in Brazilian strains of Schistosoma mansoni evaluated by means of morphometric analysis of cercariae of both sexes

Morphometrics of Brazilian strains (BH, SJ and CMO) of Schistosoma mansoni cercariae were obtained with a computerized image analyzer (IMAGE PRO PLUS, MEDIA CYBERNETICS), considering the following characters: body area, tail, furcae, oral and ventral suckers and distance between them. For statistical analysis, the variance test (one-way Anova) was applied and significant differences of p< 0.05 were considered. All morphometric values in the BH strain were significantly higher (p< 0.05) than in the others. Lower values were obtained in females of SJ strain for all characters, excepting the body area. Only this character showed to be significantly different in males and females of the three strains. Specimens of both sexes in the BH and SJ strains showed significant differences regarding all characters. It was observed that this morphometric analysis permits the characterization of strains and also the sex identification in S. mansoni cercariae. Due to its feasibility, this method can be applied as a tool in laboratories devoid of more complex equipment.

A Multiplex-PCR approach to identification of the Brazilian intermediate hosts of Schistosoma mansoni

Due to difficulties concerning morphological identification of planorbid snails of the genus Biomphalaria, and given a high variation of characters and in the organs with muscular tissue, we designed specific polymerase chain reaction (PCR) primers for Brazilian snail hosts of Schistosoma mansoni from available sequences of internal transcribed spacer 2 (ITS2) of the ribosomal RNA gene. From the previous sequencing of the ITS2 region, one primer was designed to anchor in the 5.8S conserved region and three other species-specific primers in the 28S region, flanking the ITS2 region. These four primers were simultaneously used in the same reaction (Multiplex-PCR), under high stringency conditions. Amplification of the ITS2 region of Biomphalaria snails produced distinct profiles (between 280 and 350 bp) for B. glabrata, B. tenagophila and B. straminea. The present study demonstrates that Multiplex-PCR of ITS2-DNAr showed to be a promising auxiliary tool for the morphological identification of Biomphalaria snails, the intermediate hosts of S. mansoni.

Cytotaxonomy of Simulium cauchense Floch & Abonnenc and Simulium quadrifidum Lutz (Diptera: Simuliidae) in Brazilian Amazonia

Simulium cauchense Floch & Abonnenc and Simulium quadrifidum Lutz are widely distributed in the Amazon region and are morphologically similar at the larval and pupal stages. Chromosomally, these species are readily distinguished by the position of the nucleolar organizer, which is in the short arm of chromosome I in S. cauchense and in the long arm of chromosomes III in S. quadrifidum. They also differ by three fixed inversions. Sex chromosomes are undifferentiated in both species. Chromosomal resolution of the two species allowed us to evaluate four structural features previously used as diagnostic aids at the larval stage. Characters that distinguish larvae of the two species are the number of branches and branching patterns of the dorsal abdominal setae and the dark band on each primary fan. Branching patterns of the gill histoblasts were often diagnostic, with S. quadrifidum exhibiting more proximal branching and S. cauchense more distal branching. Sites where both species occurred sometimes had larvae with one petiole branching proximally and the other distally; in these cases examination of the chromosomes permitted assignment of the specimen to species. Pigmentation patterns of larvae, on the other hand, are highly variable. Color typically is sex linked in both species.

Resurrection of Anopheles goeldii from synonymy with Anopheles nuneztovari (Diptera, Culicidae) and a new record for Anopheles dunhami in the Brazilian Amazon

Nucleotide sequences of the internal transcribed spacer 2 (ITS2) rDNA and partial sequences of the cytochrome coxidase subunit I (COI) mtDNA and white gene nDNA were obtained from specimens of Anopheles nuneztovari A collected in Macapá (state of Amapá), Óbidos, Prainha and Almeirim (state of Pará), Itacoatiara and Parintins (state of Amazonas), Brazil, and compared with previously published sequences of A. nuneztovari s.l. Results of the Bayesian phylogenetic analyses performed using either COI or combined ITS2, COI and white gene sequences suggest that An. nuneztovari B/C is distinct from specimens obtained in the Amazonas/Solimões River basin. Anopheles goeldii, currently in synonymy with An. nuneztovari, was described from individuals collected in Belterra (= Fordlândia) in the Tapajós River, state of Pará, Southern Amazonas River. Morphological comparisons of the characteristics of the male genitalia indicated that An. nuneztovari A and An. goeldii are similar but distinct from An. nuneztovariB/C by the apex of the aedeagus. In considering the results of the phylogenetic analyses and morphological comparisons, An. goeldii is resurrected from synonymy with An. nuneztovari. Additionally, Anopheles dunhamiis reported for the first time in Parintins. This species can be distinguished from An. goeldiiby characters of the male genitalia and molecular data.

Culicoides baniwa sp.nov. from the Brazilian Amazon Region with a synopsis of the hylas species group (Diptera: Ceratopogonidae)

A new species of the Culicoides (Hoffmania) hylas species group, Culicoides baniwa Felippe-Bauer is described and illustrated based on a female specimen from the state of Amazonas, Brazil. A systematic key, wing photographs, diagramme of the legs pattern, table with numerical characters of females and a synopsis of the 11 species of the C. hylas group are presented. This paper further presents a new record of Culicoides pseudoheliconiae Felippe-Bauer out of the previously defined geographic distribution of the hylas species group, in the province of Misiones, Argentina.

A pictorial key and diagnosis of the Brazilian genera of Micropezidae (Diptera, Nerioidea)

A pictorial key and diagnosis of the Brazilian genera of Micropezidae (Diptera, Nerioidea). This paper provides the first pictorial key and diagnosis for the Brazilian genera of the Micropezidae, based on external morphological characters illustrated with photographs. The key includes 13 genera: Cardiacephala Macquart, Cliobata Enderlein, Grallipeza Rondani, Metasphen Frey, Micropeza Meigen, Parasphen Enderlein, Planipeza Marshall, Plocoscelus Enderlein, Poecilotylus Hennig, Ptilosphen Enderlein, Rainieria Rondani, Scipopus Enderlein and Taeniaptera Macquart. For each genus, the species known to occur in Brazil are listed and their distribution records, including new ones, are provided.