Dipetalonema graciliformis (Freitas, 1964) from the red-handed tamarins (Saguinus midas, Linnaeus, 1758) in French Guiana.

Six Dipetalonema species have been reported from Neotropical monkeys, Dipetalonema gracile, Dipetalonema graciliformis and Dipetalonema caudispina being the dominant species found in French Guiana primates. Adult filarioids isolated from the abdominal cavity of tamarins (Saguinus midas) in French Guiana were morphologically and molecularly identified as D. graciliformis. Phylogenetic analysis based on DNA and amino acid sequences of the cox1 gene as well as the concatenated sequences of the cox1 and the 18S genes indicated that D. graciliformis belongs to the clade 4 (ONC4) of Onchocercidae. Blast analysis of the 18S rDNA revealed that D. graciliformis in the studied tamarins is conspecific with the filarioid circulating in howler monkeys (Alouatta macconnelli) in French Guiana, previously referred to as unidentified Onchocercidae species.

Co-infection with filarial nematodes in Sapajus macrocephalus and Cebus albifrons (Primates: Cebidae) from the Peruvian Amazon.

Dipetalonema caudispina (Molin, 1858) and D. gracile (Rudolphi, 1809) (Filarioidea: Onchocercidae) are two of six known species of filarial nematodes that parasitize Neotropical non-human primates. Adult filariae were collected from the thoracic and abdominal cavities of 38 of 44 specimens of Sapajus macrocephalus (Spix, 1823) and nine of ten specimens of Cebus albifrons (Humboldt, 1812) (Primates: Cebidae), distributed in the Yavarí-Mirín river basin and used locally for human consumption. Co-occurrence of D. caudispina and D. gracile is reported for the first time, with a prevalence of 18.5% (10 of 54 hosts examined). Our finding of D. caudispina and D. gracile in cebids from the Peruvian Amazon constitutes a new geographical record for both filariae, two new host records for D. caudispina, and the first report of D. gracile in S. macrocephalus. In addition, we provide morphometric data for D. caudispina, complementing the original description, as well as scanning electron microscopy details on the structure of the area rugosa and number of caudal papillae in males.

Occurrence of Dipetalonema gracile in a wild population of woolly monkey Lagothrix poeppiigii in the northeastern Peruvian Amazon / Ocorrência de Dipetalonema gracile em uma população selvagem de macaco barrigudo Lagothrix poeppigii no nordeste da Amazônia peruana

Abstract Dipetalonema gracile (Rudolphi, 1809) (Filarioidea: Onchocercidae) is one of six species of cavities filarial parasites of Neotropical non-human primates. The present study recorded the occurrence of D. gracile, provides morphological and morphometric data and extends the geographical distribution. Adult filariae were obtained from the thoracic and abdominal cavities of 38 specimens of woolly monkey, which were used for local human consumption, in the northeastern Peruvian Amazon. Male and female filarids were processed and analysed using light and scanning electron microscopy. Details of the cephalic papillae, post-cloacal bands and papillae, vulva, phasmid position and lateral appendages are showed by scanning electron microscopy and is recorded the occurrencce of Lagothrix poeppigii monkey as a new host of this filaria in the Yavari-Mirin river basin, Peruvian Amazon.

Resumo Dipetalonema gracile (Rudolphi, 1809) (Filarioidea: Onchocercidae), é uma das seis espécies de filarias parasitas de primatas não humanos neotropicais. O presente trabalho registra a ocorrência de D. gracile , proporciona dados morfológicos e morfométricos e amplia sua distribuição geográfica. Filárias adultas foram obtidas da cavidade torácica e abdominal de 38 espécimes de macaco barrigudo, que foram utilizados para consumo humano local. Essa espécie de primatas não humanos neotropicais tem distribuição ao nordeste da Amazônia peruana. Filarídeos machos e fêmeas foram processados e analisados pela microscopia de luz e microscopia eletrônica de varredura. Detalhes das papilas cefálicas, bandas e papilas pós-cloacais, vulva, posição dos fasmídeos e apêndices laterais são mostradas pela microscopia eletrônica de varredura e registra-se a ocorrência do macaco Lagothrix poeppigii como novo hospedeiro desta filaria na bacia do rio Yavari-Mirin na Amazônia peruana.

Occurrence of Dipetalonema gracile in a wild population of woolly monkey Lagothrix poeppiigii in the northeastern Peruvian Amazon.

Dipetalonema gracile (Rudolphi, 1809) (Filarioidea: Onchocercidae) is one of six species of cavities filarial parasites of Neotropical non-human primates. The present study recorded the occurrence of D. gracile, provides morphological and morphometric data and extends the geographical distribution. Adult filariae were obtained from the thoracic and abdominal cavities of 38 specimens of woolly monkey, which were used for local human consumption, in the northeastern Peruvian Amazon. Male and female filarids were processed and analysed using light and scanning electron microscopy. Details of the cephalic papillae, post-cloacal bands and papillae, vulva, phasmid position and lateral appendages are showed by scanning electron microscopy and is recorded the occurrencce of Lagothrix poeppigii monkey as a new host of this filaria in the Yavari-Mirin river basin, Peruvian Amazon.

Characterization of the heartworm Acanthocheilonema spirocauda (Leidy, 1858) Anderson, 1992 (Nematoda: Onchocercidae) in Scandinavia.

The heartworm Acanthocheilonema spirocauda (Leidy, Proc Acad Nat Sci Philadelphia 10:110-112, 1858) Anderson, 1992 is described from material collected from harbour seals in Scandinavia and compared with types and other specimens described by Anderson (Can J Zool 37:481-493, 1959) from harbour seals in eastern USA. Most morphometric characters of the material from USA fall within the ranges established for the Scandinavian one. Some intraspecific variability in the organisation of papillae on the male tail was detected among the Scandinavian specimens. Differences between the specimens from Scandinavia and Eastern USA are also found in the organisation of papillae on the tail of males and females. An excretory pore was not discernible, but a clearly hemizonid-like structure is described. For the first time, scanning electron micrographs present external morphological structures of the species.

A new species of Dipetalonema (Filarioidea: Onchocercidae) from Ateles chamek from the Beni of Bolivia.

We describe a new species of Dipetalonema occurring in the body cavity of Ateles chamek (Humboldt, 1812) from north-central Bolivia. Morphologic characters serving to separate Dipetalonema yatesi n. sp. from known forms include a vagina vera with a simple tube and thin walls and a left spicule, which possesses a handle shorter than the lamina (ratio 2.7); the latter displays an anterior membranous alae similar in length to the terminal flagellum, a distal extremity of the left spicule within a simple hook and a membrane, phasmids at the basis of the lappets, and heterogeneous muscles occupying the whole cavity. Dipetalonema yatesi n. sp. can be separated from Dipetalonema robini, Dipetalonema gracile, and Dipetalonema graciliformis, between other characters, in having a simple vagina vera instead of a sinuous one, and from Dipetalonema caudispina and Dipetalonema freitasi in having the lamina of the left spicule divided in a membranous alae and a terminal flagellum.

Stage-specific development of a filarial nematode (Dipetalonema dracunculoides) in vector ticks.

This paper reports the development of the canid filarial worm, Dipetalonema dracunculoides, in the brown dog tick, Rhipicephalus sanguineus by determining whether development is similar within larval, nymphal and adult stages of infected ticks. This study demonstrates that only infected nymphal ticks can support the complete development of the filarial worm. Infected larval ticks are not suitable intermediate hosts, nor are infected adults. Development depends on some stage-specific property of the vector, and the maturation to the infective stage is stimulated during the course of the nymphal-adult moult.

Comparison of the cuticular structure of parasitic nematodes recognized by immunocytochemical and lectin binding studies.

The cuticle structure of some nematode species was studied by immunogold and lectin-gold techniques. The gold labelling made it possible to distinguish the cuticle layers by the distribution and/or the density of the marker. On the other hand, no labelling pattern was found which led to a clear grouping of the layers into larger 'zones', since there were no subunits consisting of more than one layer which reacted in a characteristic way as compared to the rest of the cuticle. The outer surface of the epicuticle of parasitic adult worms turned out to be highly inert; it did not react with any of the antibodies or lectins tested. The cuticle of parasitic nematodes seems to function as a protection against the host's defense mechanisms rather than as an interaction site. An immunogenic component on the surface was only found in infective larvae. All antibodies and lectins showed a preferential binding to the electron dense layers and fibrous structures (HPL/GalNAc, WGA/GlcNAc) or to the amorphous ground-substance (Con A/Glc, RCA I/Gal).

The acid phosphatase activity and morphological characteristics of Dipetalonema dracunculoides (Cobbold, 1870) microfilariae.

The acid phosphatase activity and some morphological characteristics of Dipetalonema dracunculoides microfilariae are described. Their morphological features are closely related to those of the pathogenic Dirofilaria immitis when Knott's technique is used for the microfilarial diagnosis. The acid phosphatase activity pattern found in Dip. dracunculoides microfilariae is clearly different from those previously described for D. immitis, D. repens and Dip. reconditum.

[Dipetalonema dracunculoides (Cobbold, 1870) (Nematoda: Onchocercidae) in an imported dog]. / Dipetalonema dracunculoides (Cobbold, 1870) (Nematoda: Onchocercidae) bij een geïmporteerde hond.

Dipetalonema dracunculoides was found in the abdominal and thoracic cavities of an imported dog.

[A 5th filaria of the genus Dipetalonema, parasite of South American monkeys]. / Une cinquième filaire du genre Dipetalonema, parasite de singes Sud-Américains.

Description of D. freitasi n. sp., a parasite of Cebus capucinus: this species, close to D. caudispina, is distinguished by the slightly more complex structure of the vagina and right spicule, the lack of area rugosa on the tail and by the shorter microfilaria. Additional morphological data on the male of D. robini Petit et al., 1985 are given. A comparative table of 4 principal evolutive characters of the genus Dipetalonema (vagina, left and right spicules, epithelio-muscular body wall) is given. D. caudispina and D. freitasi n. sp. represent a small primitive group opposed to the more evolved one made up of D. robini, D. gracile and D. graciliformis.

Acanthocheilonema sabanicolae n. sp. (Filarioidea: Onchocercidae) from the savanna armadillo (Dasypus sabanicola) in Venezuela, with comments on the genus Acanthocheilonema.

A new species of Acanthocheilonema, Acanthocheilonema sabanicolae n. sp., is described from the subcutaneous tissues of the savanna armadillo (Dasypus sabanicola) in Venezuela. The adults (females 25-30.6 mm long by 61-78 micron wide; males 10.9-15.3 mm long by 42-44 micron wide) and the microfilariae (112-131 micron long by 3-5 micron wide) are the smallest within the genus. The microfilaria, a skin dweller, assumes a characteristic C-shaped curve, when fixed in 2% formalin, which serves to distinguish A. sabanicolae from others in the genus. Moreover, the spicules are notably smaller than any others in the Acanthocheilonema. Acanthocheilonema sabanicolae is the first species in this genus to be described from edentates, and, along with A. reconditum of dogs and A. pricei of opossums, is the third species of Acanthocheilonema to be reported from South America. Morphological features, vectors, and vertebrate hosts of the genus Acanthocheilonema are reviewed.

Transplanted Dipetalonema viteae in the jird: effect of worm burden on parturition rates and microfilaremia.

Dipetalonema viteae was studied in the jird, Meriones unguiculatus, to determine the mechanism controlling the level of peripheral microfilaremia. Jirds killed 40 days after infection served as donors of female worms of known age and reproductive status. These worms were transplanted into uninfected jirds and the resultant microfilaremias were monitored. After approximately 100 days, the recipient jirds were killed and 58% of the transplanted worms were recovered alive but depleted of sperm and microfilariae, regardless of the total number implanted in a given host. A direct linear relationship between microfilaremia and the number of recovered adult worms was found. Based on the uniform absence of sperm and microfilariae in the recovered worms it was concluded that female worms, under the conditions of the present study, do not control the peripheral microfilaremia in multi-worm infections through a reduced parturition rate.

Note on Dipetalonema (Chenofilaria) japonica Uni, 1983 from Japanese black bear. Supplementary description.

Supplementary description was made on the specimens of D. (Chenofilaria) japonica from the black bear (Selenarctos thibetanus japonicus) of Japan. Scanning electron microscopy (SEM) revealed the en face view of the head and the terminal tip of the tail of the female adults. The tail of the male is described in this report, and the microfilaria is confirmed. The adult specimens were found predominantly in the subcutaneous connective tissue near the scapula along with one microfilaria. Microfilariae were not found in the blood.

Dipetalonema (Alafilaria) hydrochoerus subgen. et sp. n. (Nematoda: Filarioidea) from Colombian capybaras.

Dipetalonema (Alafilaria) hydrochoerus subgen. et sp. n. is described from specimens recovered from skeletal muscle fascia of the capybara, Hydrochoerus hydrochacris, from several localities in Colombia, South America. The microfilaria, which is found in the skin of the host, is also described for the first time. The monotypic species of the subgenus Alafilaria can be distinguished from existing Dipetalonema subgenera and all filariae known to us, on the basis of numerous preanal caudal papillae in males, small size of petals on the caudal extremity of each sex, and low, bluntly-rounded lateral alae in the cuticle of adult worms of both sexes. Unusual and distinctive features of the microfilaria include conspicuous lateral cuticular alae and a caudal extremity devoid of nuclei.

Dipetalonema (Dasypafilaria) averyi subgen. et sp. n. (Nematoda: Filarioidea) from the nine-banded armadillo, Dasypus novemcinctus in Louisiana.

A new filarial nematode, Dipetalonema (Dasypafilaria) averyi subgen. et sp. n., is described from the omentum of armadillos (Dasypus novemicinctus) for southern Louisiana. Within the genus, the large buccal cavity, the absence of a gubernaculum, the reduced number of caudal papillae, the large caudal lappets, and the sheathed microfilaria serve to distinguish the subgenus Dasypafilaria from other subgenera. The small size of D. averyi (females 5.3-9.5 mm long by 70-90 micrometers wide; males 3.8-5.5 mm long by 46-70 micrometers wide) readily distinguishes it from other species in the genus. It also is distinguished by its rounded cephalic extremity, the location of the vulva at the level of the base of the esophagus, the morphology of the spicules, and the size and configuration of the microfilaria.