Ciclo de vida de Gordiida (Nematomorpha)

Los Gordiida parasitan generalmente insectos terrestres. Sin embargo los adultos habitan cuerpos de agua dulce, donde copulan y ponen los huevos en forma de cordones. Esto plantea el dilema de cómo alcanzar un hospedador definitivo. Hay 4 formas posibles para alcanzar el objetivo: 1. es esperar ser ingerido cuando el potencial hospedador se acerca a tomar agua, 2. es enquistarse en el medio ambiente hasta ser ingerida por el hospedador, 3. es penetrar activamente el tegumento de un hospedador intermediario y luego enquistase en sus tejidos a la espera de ser ingerido por el hospedador definitivo y 4. es ingerida pasivamente por un hospedador intermediario y penetrar la pared del intestino, enquistarse en los tejidos para luego ser ingerida por el hospedador definitivo.Asociación Parasitológica Argentin

Análisis comparativo de la morfología y ciclo de vida de Mermithidae (Nematoda) y de Gordiida (Nematomorpha)

Los Gordiida (Nematomorpha) han sido confundidos por mucho tiempo con los Mermithida (Nematoda) debido a la morfología de los estados adultos y por algunas similitudes en el ciclo de vida. Los Nematomorpha incluyen unas 350 especies, cinco especies marinas pertenecen al Subphylum Nectonematida, cuyos hospedadores son crustáceos, decápodos y el resto de las especies (Subphylum Gordiida) son parásitos de artrópodos terrestres, principalmente insectos (coleopteros, ortopteros, mántidos y blataridos, entre otros). Entre las similitudes morfológicas entre Gordiida y Mermithida están la forma y el color.Asociación Parasitológica Argentin

South American species of Paragordius Camerano, 1897 (Gordiida, Nematomorpha), with redescription of Paragordius minusculus and a description of a new species

Paragordius is a genus of Gordiida with a worldwide distribution, but with a scarce specific diversity. Sixteen species of the genus Paragordius have been described so far. In many cases, as with the other genera of Gordiida, the original descriptions of the species are insufficient due to the limitations of the techniques employed. In this work the holotypes of P. minusculus and P. esavianus are redescribed by scanning electron microscopy (SEM), a new species of Paragordius is described, the distribution for P. esavianus and P. varius is enlarged and a new host record of P. esavianus is presented.Facultad de Ciencias Naturales y Muse

Scanning electron microscopy of Spinochordodes tellinii (Camerano, 1888), (Gordiacea, Nematomorpha)

There are many species of Nematomorpha which are deficiently described and therefore pose doubts about their actual taxonomic position. This is the case with Spinochordodes tellinii (Camerano, 1888), which was transferred to four different genera and has been recently considered as species incertae sedis. A female of Spinochordodes tellinii is redescribed in this work under light microscopy and Scanning Electron Microscopy. Cuticle details, shapes and areolar distribution and the features as well as the location of spiniform structures are analysed. The systematic position is discussed.Facultad de Ciencias Naturales y Muse

South American species of Paragordius Camerano, 1897 (Gordiida, Nematomorpha), with redescription of Paragordius minusculus and a description of a new species

Paragordius is a genus of Gordiida with a worldwide distribution, but with a scarce specific diversity. Sixteen species of the genus Paragordius have been described so far. In many cases, as with the other genera of Gordiida, the original descriptions of the species are insufficient due to the limitations of the techniques employed. In this work the holotypes of P. minusculus and P. esavianus are redescribed by scanning electron microscopy (SEM), a new species of Paragordius is described, the distribution for P. esavianus and P. varius is enlarged and a new host record of P. esavianus is presented.Facultad de Ciencias Naturales y Muse

Morphometric characterization of the Chordodes brasiliensis (Nematomorpha) larvae in The Tala river, Catamarca province

The Gordiida (Nematomorpha) are obligate parasites of insects. Adults inhabit permanent and temporary aquatic environments. After mating, the female expels egg strings in the substrate or aquatic vegetation. The aim of this work was the morphometric characterization of the Chordodes brasiliensis larvae from the Tala River, Catamarca province.Centro de Estudios Parasitológicos y de Vectore

Revision of the genus Beatogordius (Gordiida, Nematomorpha) : II. South American species with description of two new species

Seven species of Beatogordius (Nematomorpha) have been reported from South America. A reinvestigation could not reproduce a number of determinations indicated in the literature. B. deshayesi has been a misinterpretation and the status of B. irregularis appears to be very uncertain, because no generic characters could be found. The descriptions of B. alfredi and B. latastei confirm that these species belong to South America only. In B. abaiconus we found adhesive warts anterior of the male cloacal opening. These structures were to date only known from the genus Gordionus. In the posterior end of females from B. alfredi and B. variabilis, short paired rows of bristles were present which had to date only been known from the African species B. equinatus. Two new species, B. funis and B. palustre could be added to the genus.Facultad de Ciencias Naturales y Muse

Redescription and new records of freshwater Nematomorpha (Gordiida) from Chile, with the description of two new species

Hasta el momento solo han sido citadas para Chile cuatro especies de Gordiida (Nematomorpha). En este trabajo se describen dos especies nuevas, Gordionus enigmaticus y Gordius austrinus. Gordionus enigmaticus se caracteriza por la variación en la forma de las areolas a lo largo del surco longitudinal ventral y porque en la región pre-cloacal del extremo posterior, los campos de cerdas están ausentes. Gordius austrinus se distingue de otras especies de Gordius por la presencia de un reborde precloacal que limita la depresión del área cloacal, por la prominencia cuticular donde se encuentra la abertura cloacal y por el patrón de distribución de las cerdas en el extremo posterior. Asimismo se redescriben ultraestructuralmente a Gordius paranensis, G. robustus y Neochordodes meridionales y se señala la distribución para Chile de cada especie.Only four species of Gordiida (Nematomorpha) are known from Chile. This paper describes two new species Gordionus enigmaticus and Gordius austrinus. Gordionus enigmaticus is characterized by the variation in the shape of the areoles along the longitudinal ventral furrow and by the absence of the precloacal fields of bristles at the terminal end. Gordius austrinus can be distinguished from other Gordius species by the presence of the precloacal ledge bounding the cloacal area depression, by the cuticular prominence where the cloacal opening lies and by the distribution pattern of the bristles at the posterior end. Likewise, Gordius paranensis, Gordius robustus and Neochordodes meridionales are ultrastructuraly redescribed and the distribution of each of them in Chile is given.Facultad de Ciencias Naturales y Muse

Revision of the genus Beatogordius (Gordiida, Nematomorpha) : II. South American species with description of two new species

Seven species of Beatogordius (Nematomorpha) have been reported from South America. A reinvestigation could not reproduce a number of determinations indicated in the literature. B. deshayesi has been a misinterpretation and the status of B. irregularis appears to be very uncertain, because no generic characters could be found. The descriptions of B. alfredi and B. latastei confirm that these species belong to South America only. In B. abaiconus we found adhesive warts anterior of the male cloacal opening. These structures were to date only known from the genus Gordionus. In the posterior end of females from B. alfredi and B. variabilis, short paired rows of bristles were present which had to date only been known from the African species B. equinatus. Two new species, B. funis and B. palustre could be added to the genus.Facultad de Ciencias Naturales y Muse

South American species of Paragordius Camerano, 1897 (Gordiida, Nematomorpha), with redescription of Paragordius minusculus and a description of a new species

Paragordius is a genus of Gordiida with a worldwide distribution, but with a scarce specific diversity. Sixteen species of the genus Paragordius have been described so far. In many cases, as with the other genera of Gordiida, the original descriptions of the species are insufficient due to the limitations of the techniques employed. In this work the holotypes of P. minusculus and P. esavianus are redescribed by scanning electron microscopy (SEM), a new species of Paragordius is described, the distribution for P. esavianus and P. varius is enlarged and a new host record of P. esavianus is presented.Facultad de Ciencias Naturales y Muse