Cristina De Villalobos

Thirty‐five species of Chordodes have been reported from Africa. The original description of several of these species is incomplete and needs reinvestigation by scanning electron microscopy (SEM) which allows the observation of fine structural details. We reinvestigated five of these species: Chordodes gariazzi, C. heinzei, C. kolensis, C. muelleri, and C. ruandensis. All of them show crowned areoles occurring in clusters. These clusters are formed by crowned areoles that are surrounded by another areolar type. The females of C. kolensis and C. muelleri have polymorphic crowned areoles with both short and long filaments; these areoles are only observed along the ventral groove. Chordodes gariazzi, C. heinzei, and C. muelleri have five areole types, C. ruandensis has three different types of areole, and C. kolensis displays a sexual dimorphism where males have six types of areole and females have seven areole types. Chordodes gariazzi, C heinzei, and C. muelleri have tubercle areoles. Host data and a new distribution record of C. kolensis are reported.

Two questions are of interest concerning the male reproductive system in Gordiida: (1) is the epithelium surrounding the testis continuous or discontinuous and (2) is the type of spermatozoon as described at the transmission electron-microscopical level for the two species of Gordius typical for all Gordiida? An examination of the South American species Pseudochordodes bedriagae has allowed us to add new information to this poorly studied phylum. Testicular tubes are large, filled with spermatozoa, and surrounded by a continuous epithelium. The epithelial cells that line the posterior testes occasionally overlap, and their cytoplasm is narrow and contains dense granules, abundant endoplasmic reticulum, and vesicles. The plasma membrane possesses microvilli with many filaments. This epithelium rests on a basement membrane. The spermatozoa in P. bedriagae resemble the known spermatozoa of two Gordius species but differ in presenting a uniform halo layer of less dense chromatin that surrounds the dense chromatin in the nucleus. The finding that a similar type of spermatozoa occurs in both genera (Pseudochordodes and Gordius) makes it likely that it is present in all other Gordiida and is therefore an autapomorphy of the Gordiida.

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.

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. De nombreuses espèces de Nematomorpha sont insuffisamment décrites ce qui pose des problèmes sur leur validité et leur position systématique. C'est le cas de Spinochordodes tellinii (Camerano, 1888) qui a été rattaché à quatre genres différents et considéré récemment comme espèce incertae sedis. Dans ce travail, une femelle de S. tellinii est redécrite en utilisant le microscope optique et le microscope à balayage. Des détails sur la cuticule, la forme, la distribution aréolaire et la localisation des structures spiniformes sont donnés. La position systématique de l'espèce est discutée.