Chordodes jelkae, Schmidt-Rhaesa, Andreas, 2016

Schmidt-Rhaesa, Andreas, 2016, The collection of Nematomorpha in the Zoological Museum Hamburg, including description of a new species, Chordodesjelkae sp. n., Zoosystematics and Evolution 92 (2), pp. 211-250 : 214-215

Chordodes jelkae sp. n.

Material examined.

V10960 (2 females). Fig. 15 A–F.

Location.

Rwanda, Kabgayi, "Poste de Kigali".

Holotype.

Specimen 10960 (I).

Remarks from the catalogue.

Collected by "Freres Rodrigues v.d. Weissen Vätern " (no collection date). Received by the museum on September 20, 1929.

Etymology.

The species is named after and dedicated to my oldest daughter, Jelka.

Descsription.

The two females measure 90 (I) and 85 (II) mm in length and 0.9/1.0 mm in diameter, respectively. The anterior end tapers towards the tip. The body colour is a dark brown general occurrence, with brown basic colour and darker patches (the "leopard pattern"). The anterior tip is white and blends into the brown body colour. Specimen (I) is well preserved, characters of specimen (II) are less well visible (Fig. 15F). The following description is therefore based on specimen (I), which is designated as the holotype. The cuticle shows the characteristic types of areoles known from other species of Chordodes . The simple areoles are roundish, often longer than broad (Fig. 15C, E). Their longer axis is perpendicular to the longitudinal axis of the animal. Simple areoles are closely together (Fig. 15C, E). On the apical side they have a tuft of short (about 3µm) bristles (Fig. 15 C–E), in some cases these fine bristles are dissolved and do not form a clear tuft. Among the simple areoles are occasional tubercle areoles, the tubercle is in some cases pointed (Fig. 15E). Thorn areoles were not observed. Crowned areole clusters are composed of two central crowned areoles with moderately long apical filaments (<20 µm), which are surrounded by 10-12 circumcluster areoles (Fig. 15C). The apical filaments of the crowned areoles originate laterally around a more or less flat apical surface of the areole, this surface is divided by several grooves into several compartments (Fig. 15C). The apical filaments may divide basally, but more distal divisions were not observed. The circumcluster areoles have a tuft of bristles on top (Fig. 15C). This tuft varies in its form, it either resembles the tuft of simple areoles as all bristles originate in the center of the apical surface or, in some circumcluster areoles, the apical surface is flat and the bristles extend laterally, comparable (though shorter) than in crowned areoles (Fig. 15C). Along one longitudinal line, probably the ventral midline, crowned areoles have very long apical filaments (approximately 170 µm) (Fig. 15B), in contrast to crowned areoles in the remaining parts of the body, which have shorter apical filaments (Fig. 15A).

Remarks.

Species of Chordodes are quite similar in their cuticular structure. Species are distinguished by the presence or absence of particular types of areoles or when cuticular structures exhibit a particular substructure. Characteristic for this new species is the form of the simple areoles. In most species of Chordodes the simple areoles have either no bristles or scattered fine bristles on their apical surface. SEM investigations reveal that small bristles may be more abundant than known on the basis of traditional light microscopical investigation and they may even form small tuft-like structures as present, e.g. in Chordodes parabipilus Kintsurashvili, Schmidt-Rhaesa & Gorgadze, 2011 ( Kintsurashvili et al. 2011), Chordodes moutoni Camerano, 1895 ( Schmidt-Rhaesa and Yadav 2013) and Chordodes combiareolatus Schmidt-Rhaesa, Limatemjen & Yadav, 2015 (Schmidt-Rhaesa et al. 2015). Compared to these species, the tuft of bristles is larger in Chordodes jelkae sp. n. A distinct tuft of bristles is present in Chordodes villalobi , a species from Malaysia ( Schmidt-Rhaesa and Brune 2008), but this is more pronounced than in Chordodes jelkae sp. n. In combination to the shape of the tuft of bristles on the simple areoles, an important difference between all mentioned species and Chordodes jelkae sp. n. is that thorn areoles are absent in Chordodes jelkae sp. n., but present in all other species. Additinally, simple areoles are closer together in Chordodes jelkae sp. n. than in Chordodes villalobi . Characters in specimen 10960 (II) are not as well visible and its assignment to Chordodes jelkae sp. n. is likely, but not certain.