Neochordodes chordodides, Schmidt-Rhaesa & Menzel, 2005

Schmidt-Rhaesa, Andreas & Menzel, Lena, 2005, Central American and Caribbean species of horsehair worms (Nematomorpha), with the description of three new species, Journal of Natural History 39 (7), pp. 515-529 : 523-524

Neochordodes chordodides nov. sp.

( Figure 4 )

Holotype: Costa Rica, Santa Rosa Field Station , one female, from unidentified cockroach (Blattodea), coll. 16 January 2002 by B. Hanelt (Museum für Naturkunde, Berlin, Germany, accession number ZMB 7382 ) . Paratype (allotype): one male from same location and host as holotype ( Museum für Naturkunde, Berlin, Germany, accession number ZMB 7383 ) .

Description

The body colour of males is dark brown, females are medium brown. The anterior tip is white, but a following dark collar is absent. The females from Costa Rica measure 55 and 70 mm, the Costa Rica male is 70 mm long, the Belize male 95 mm. Diameters are 0.3 mm ( Belize male), 0.4 mm ( Costa Rica male), 0.5 and 0.7 mm ( Costa Rica females). The posterior end of males is without tail lobes ( Figure 4A ). In the male from Costa Rica, there is a longitudinal fold on the ventral side anterior of the cloacal opening ( Figure 4B ), which is probably an artifact. On the ventral surface, around the cloacal opening, are slender, unbranched cuticular spines ( Figure 4D ).

The cuticle contains, depending on definitions, one or two types of areole (see comments). All areoles are distinctly elevated and have fine bristles on their apical surface ( Figure 4C ). The size can vary ( Figure 4C, E ). Several areoles additionally have thicker projections (tubercles). These tubercles are sometimes in the centre of the areole, but are often displaced towards the margin ( Figure 4C, E ).

Comments

The assignment of this new species is not unequivocal. Areoles with apical processes are typical for the genus Chordodes (see Schmidt-Rhaesa 2001), but there the processes are often longer or more numerous and are restricted to fewer areoles (the crowned areoles). In some species of Chordodes , areoles other than the crowned areoles carry fine apical processes (see e.g. Chordodes queenslandi and C. brevipilus in Schmidt-Rhaesa 2002). However, as there is no Chordodes species without crowned areoles and as crowned areoles are lacking in this new species, an assignment to Chordodes is not convincing.

We place this species in the genus Neochordodes , because it has one type of areole. Strictly, there are two types, one without and one with tubercles. Two types of areole would support a placement in the genus Pseudochordodes , but there is no report of tubercle areoles in Pseudochordodes . The difference in areolar types refers to the areolar shape or size, which does not apply in the new specimen.

Distribution

Belize: Cayo, Cebada Cave, one male, coll. 9 May 1986 by G. Veni and C. Zone (Museum für Naturkunde , Berlin , Germany , accession number ZMB Entozoa 7384). Costa Rica : Santa Rosa Field Station , two females (one of them holotype) and one male (allotype), all from one unidentified cockroach (Blattodea), coll. 16 January 2002 by B. Hanelt [Museum für Naturkunde, Berlin, Germany, accession number ZMB 7382 (holotype) and 7383 (allotype), further female in collection of A. Schmidt-Rhaesa, SR 726] .

Figures

Figure 4. Neochordodes chordodides n. sp. (A) Ventral view of male posterior end from Belize specimen, arrow indicates position of cloacal opening (not visible). (B) Longitudinal fold (arrow) on ventral side of posterior end of the male from Costa Rica. (C) Cuticle in midbody of holotype, some areoles with tubercles (arrows). (D) Long and slender bristles from the ventral side of the male posterior end in the region around the cloacal opening. (E) Light microscopical image of the cuticle. Apical bristles are hardly visible.