Chordodes cf. moutoni Camerano, 1895

Schmidt-Rhaesa, Andreas & Schwarz, Christian J., 2016, Nematomorpha from the Philippines, with description of two new species, Zootaxa 4158 (2), pp. 246-260 : 255-256

Chordodes cf. moutoni Camerano, 1895

( Figs 8A–L )

Chordodes cf. moutoni sp. (1). Locality: Candari near Pandan, Antique, Panay, Philippines ; collected by C. J. Schwarz on September 25–26, 2010. Emerged from male Creobroter meleagris Stål, 1877 (Mantodea) . Deposited in the Zoological Museum Hamburg, accession number V13374 . One male, length 90 mm, diameter 0.6 mm. Cuticular structures are partly not well visible, and partly appear to be covered by some material of unknown nature ( Fig. 8G ). The surface of the structure is often very coarse. Simple areoles are roundish structures, but surface structures cannot be documented reliably due to the coarse surface. Tubercle areoles, thorn areoles and bulging areoles were observed (partly in Fig. 8G ). Crowned areoles occur in pairs, a tubercle between the two areoles may or may not be seen. A crown of short apical filaments extends laterally and around the entire circumference of the areoles ( Fig. 8G ). The pairs of crowned areoles are surrounded by about 12 circumcluster areoles which are more elevated than the simple areoles and appear to carry apical bristles. Crowned areoles with long filaments were not observed. The posterior end is partly covered with larval cuticle and further structures could not be observed. The description best fits that of Chordodes moutoni , first described from China ( Camerano 1895). Later , specimens from Malaysia ( Camerano 1899, 1901, Schmidt-Rhaesa & Brune 2008) and again China ( Wu & Tang 1933) were assigned to this species. Zanca & De Villalobos (2005) investigated material from the type series from the Muséum National d´ Histoire Naturelle in Paris and assigned a lectotype and a paralectotype. Chordodes moutoni has simple areoles of irregular structure, and possesses tubercle, thorn and bulging areoles. The crowned areoles have moderately long filaments, which extend laterally in the type material. The exact form of the apical filaments differs and the arrangement is not as regular in the type material as in the specimen reported here. Due to these small differences and because fine structural details could not be observed well enough, we regard this specimen as “cf.”, i.e. being close to C. moutoni .

Chordodes cf. moutoni sp. (specimens 2–5). Locality: Toog Bakong on Mt. Madja-as , Culasi, Antique, Panay, Philippines ; ~ 500 m; primary riverine forest; collected by C. J. Schwarz et al. on November 17, 2010. All four specimens emerged from a female of an undescribed species of Theopompa (Mantodea) found on a rock near a river (description of host in preparation by second author). Host is usually bark-dwelling, this specimen may have been on its way to water in order to release the specimens, two males and two females. Deposited in the Zoological Museum Hamburg, accession numbers V13375 to V13378 . Two males and two females (male 1 = specimen 2, male 2 = specimen 3, female 1 = specimen 4, female 2 = specimen 5). Length of males 135 and 140 mm, of females 200 and 230 mm. Diameter of males 0.6 and 0.7 mm, of females 0.9 and 1.0 mm. Cuticular features were best observed in female 2. In both males the cuticle was quite dirty and no reliable details could be seen. In both females, simple areoles in the midbody region are strongly structured by a system of grooves perpendicular to the longitudinal axis of the animal. These grooves structured the cuticle between the areoles in ridges ( Fig. 8A, F ). Areoles appear as elevations, but continuous with the interareolar ridges and grooves ( Fig. 8A ). In female 2, areoles in the posterior part of the animal are more individualized, closer together and the interareolar pattern is not as clear. Simple areoles are roundish, with a smooth surface and some bristles on top ( Fig. 8J ). Tubercle areoles were seen in both females ( Fig. 8A, J ), and thorn areoles were seen in male 2 and female 2 ( Fig. 8D–F ). In female 2, bulging areoles are clearly present ( Fig. 8J ). These are areoles that resemble simple areoles in their structure, but are further elevated and occur as singles, in pairs or in groups of three ( Fig. 8J ). Pairs of crowned areoles are present, the apical filaments are moderately long ( Fig. 8B, C, E, J ). The fine structure of the apical filaments differs in some details. In female 2 they form a tuft and extend from the areolar surface in all directions ( Fig. 8B, J ). In the three other specimens the filaments extend only laterally, forming a flat apical surface ( Fig. 8C, E ). Apical filaments are of varying thickness, and some are branching ( Fig. 8C, E ). Crowned areoles with very long apical filaments were observed on the ventral side of female 2 ( Fig. 8F ). The long filaments are present in addition to the shorter filaments and are thicker than the small ones ( Fig. 8F ). About 10–12 circumcluster areoles are present around the crowned areoles, they have a tuft of apical bristles ( Fig. 8B, C ). The female posterior end has an areolefree region around the terminal cloacal opening. This region is slightly depressed ( Fig. 8H ), a common feature for Chordodes females. A ventral median line with different areoles, flanked by clusters of crowned areoles, is clearly visible ( Fig. 8H, I ). At the posterior end of the males ( Fig. 8K ) there are long unbranched circumcloacal spines and a number of spines in the region around the cloacal opening, with a concentration in a paired field anterolateral of the cloacal opening ( Fig. 8L ).

When four gordiids develop within one host, they could result from one or more parasitism event(s) and therefore represent one or more species. Although not much is known about the frequency of parasitism events, it appears more likely that multiple parasitic specimens represent the same species. The few differences observed between these specimens, as well as some differences in different body regions in female 2, exemplify general problems in nematomorph taxonomy. It is still not known to what extent cuticular features might differ within and among individuals of one species. The presence of two different forms of simple areoles at the midbody and the posterior end of female 2 is notable, as is the different fine structure of the crowned areoles. The arrangement of apical filaments on the surface of the areole and branching patterns of the filaments are potential new taxonomic characters, but their potential is questionable given the variation of such patterns documented in the four specimens above. The specimens are closest in structure to Chordodes moutoni (see above). The greatest difference is the composition of crowned areoles with long filaments. The additional smaller filaments are not documented in the lectotype (Zanca & De Villalobos 2005).

Figures

FIGURE 8. A – L. Chordodes moutoni, images shown are from specimens 3 (= male 2) and 5 (= female 2). A. Overview on the cuticle in midbody in female (2). Among simple areoles are crowned areole clusters (crcl), bulging areoles (selectively encircled) and tubercle areoles (arrow). B. Magnification of a crowned areole cluster in female (2) composed of central crowned areoles and peripheral circumcluster areoles. C. Crowned areole cluster in male (2). D. Thorn in female (2). E. Thorn (thar) and crowned areoles in male (2). F. Crowned areoles with long filaments in female (2). G. Cuticular structure in specimen (1), showing crowned areole clusters, bulging areoles (bar) and tubercle areoles (tuar). H. Posterior end of female (2) with view on the ventral midline (vml). I. Magnification of the ventral midline. J. Structure of the cuticle close to the posterior end of female (2). Tubercle areoles (tuar) are encircled, bulging areoles (bar) are abundant. K. Ventral view on the posterior end of male (2) with position of the cloacal opening (co). L. Magnification of K showing spines in the region of the cloacal opening. M, N. Chordodes sp., posterior end (M) and cuticular structure (N).