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 (Comerano, 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.

Ultrastructural study of the cuticle and epidermis in Pseudochordodes bedriagae.

The light-microscopic and ultrastructural characteristics of Nematomorpha (Gordiacea) integument are described. Nine male Pseudochordodes bedriagae specimens were collected in the 1997 spring-summer period from the Sauce Chico stream in the Sierra de la Ventana, province of Buenos Aires, Argentina. Of these samples, two were analyzed using scanning electron microscopy (SEM) and the other two using transmission electron microscopy (TEM) in order to establish their morphological characteristics. The morphology of the three integumentary components (epidermis, cuticle and epicuticle) is described. Comparing our findings with those of previous studies, numerous similarities are pointed out. Some variants found would probably be related more to the various criteria of interpreting cut incidences and/or fractures than to actual differences. We assume that the different zones of the cuticle and epicuticle are segregated at the germinal stratum level by the epidermal cells, which would later undergo a slow process of maturation until their exocytosis at the level of the free epicuticular surface.

Limnomermis subtropicalis n. sp. (Nematoda:Mermithidae) a parasite of larvae of Simulium orbitale Lutz (Diptera:Simuliidae) in Argentina.

Limnomermis subtropicalis n. sp. (Nematoda:Mermithidae) a parasite of Simulium orbitale Lutz (Diptera:Simuliidae) found in Argentina is described and illustrated. This species is characterized by having medium sized amphids, pocket-shaped, medium sized vagina, sculptured spicule, and by having 9 preanal, 7 postanal papillae in the ventral row, and 12 papillae in the lateral rows.