Chordodes lasuboni, Schmidt-Rhaesa, Andreas & Yadav, Arun K., 2013

Schmidt-Rhaesa, Andreas & Yadav, Arun K., 2013, One new species and a new record of the genus Chordodes (Nematomorpha: Gordiida) from North-East India, Zootaxa 3693 (2), pp. 293-300 : 297-299

Chordodes lasuboni n. sp.

( Figures 1 B, 4, 5)

Type locality. Lasubon Hostel, North-Eastern Hill University campus, Shillong, Meghalaya, India, 25°.57'N, 91°.77'E. Collected August 6, 2012 by Ms. Luiluile Lungalang.

Holotype: A single male specimen from the type locality emerged from Hierodula sp.; alcohol preserved pieces and SEM stubs of holotype deposited in the Museum of Department of Zoology, NEHU, Shillong with the accession no. MDOZ/NEHU/INV/112.

Paratype: Nil.

Host. Holotype emerged from one specimen of Hierodula sp. ( Mantodea ) ( Fig. 1 B).

Etymology. The species is named after its type locality, the Lasubon Hostel on the campus of the North- Eastern Hill University.

Description. The holotype is 195 mm long, with a diameter of 1.2 mm in mid-body region. The specimen is dark brown in colour. The anterior end is distinctly tapered ( Fig. 5 E), the posterior end is curved ventrally.

The cuticle contains six types of areoles (terminology of Schmidt-Rhaesa et al. 2008). Most abundant are simple areoles. They are variable in size and shape, but are usually rounded structures with few tiny bristles on their apical surface ( Figs. 4 D, 4E, 4F, 5B, 5C). Tubercle areoles are present, and seem to be more abundant at the anterior end than at mid-body and at the posterior end ( Figs. 4 D, 5B). Thorn areoles are present, but rare. Of the pieces investigated here, few thorn areoles were found at the anterior end ( Fig. 5 C) and one at the posterior end ( Fig. 5 B). Thorns are slender and hook-like ( Fig. 5 C). Slender bulging areoles are abundant over the entire body ( Fig. 4 C). They occur as single areoles or in small groups. Clusters of crowned areoles and circumcluster areoles are present over the entire cuticle ( Figs. 4 A, 4B, 4C). Crowned areoles occur in pairs, and in one case a larger cluster was observed which may be due to a close proximity of two smaller clusters ( Fig. 5 D). The apical filaments of the crowned areoles are moderately long and extend slightly over the borders of the entire cluster ( Fig. 4 D, 4E, 4F). Some filaments are branched. The circumcluster areoles are slender areoles with a tuft of tiny bristles at the tip ( Fig. 4 C, 4D, 4E, 4F). Crowned areoles with very long apical filaments are present in two rows next to the ventral midline ( Figs. 4 B, 5A, 5B). Length of the apical filaments is between 150 and 200 µm.

A different cuticular structure is present in the anterior 200 µm of the body ( Fig. 5 E). In this part the simple areoles carry several hair-like structures ( Fig. 5 F). Single hairs are about 5 µm long and occur over the entire surface of the single areoles, but not in great density. A considerable number of tubercle areoles is present, the areolar base of these is similar to that of the simple areoles ( Fig. 5 F). About 200 µm posterior to the anterior tip, the cuticular pattern as described in the previous paragraph starts.

The posterior end cannot be described here in detail due to shrinkage during preparation for SEM, which did not allow close observation.

Taxonomic remarks. This specimen is unique in having many slender bulging areoles, hooked thorn areoles and a distinctly different cuticular pattern at the anterior end. Abundant slender bulging areoles are typical for two neotropical species, Chordodes brasiliensis Janda 1894 from Argentina, Brazil and Uruguay (see De Villalobos et al. 2004) and C. polytuberculatus Schmidt-Rhaesa & Menzel 2005 from Costa Rica (see Schmidt-Rhaesa & Menzel 2005). For “old world” species, this feature is new. Thorn areoles were not observed in a number of species. Although they are evident structures, they are usually rare and might have been absent on the piece of cuticle investigated. Our observations suggest that they might also be distributed unequally along the body. In C. lasuboni n. sp., thorn areoles seemed to be present only at the anterior end or at least to be rare in the mid-body region and posterior end. The slender and distinctively hook-shaped form is also a peculiar feature of the species, as thorn areoles are usually solid and slightly curved (see, e.g., Schmidt-Rhaesa et al. 2008). The different cuticular structure at the anterior end has not been described for other species, but this may be because the structure of the anterior end is rarely included in descriptions.

Figures

FIGURE 1. Specimens of Chordodes with their hosts. (A) C. moutoni with its host, Hierodula sp. (B) C. lasuboni n. sp. with its host, Hierodula sp.

FIGURE 4. Chordodes lasuboni, scanning electron micrographs. (A) Overview of dorsal side, showing the dorsal midline (dml) and many clusters of crowned areoles (cra). (B) Overview of ventral side, showing the ventral midline (vml) bordered by clusters with crowned areoles with long filaments. Brackets mark extension of these clusters. (C) Overview of cuticle from the lateral body sides showing clusters of crowned areoles and bulging areoles (arrows). (D) Cluster of crowned areoles (cra) and circumcluster areoles (cca) surrounded by simple areoles and one tubercle areoles (encircled). (E) Crowned areole cluster. (F) Crowned areole cluster showing some bulging areoles (bar) in proximity. A and C taken from anterior region of the worm, B, E and F from mid-body and D from posterior region.

FIGURE 5. Chordodes lasuboni, scanning electron micrographs. (A) Overview of ventral mid-line with crowned areoles carrying long filaments. (B) Crowned areole cluster with long filaments with tubercle areoles (tar) and one thorn areole (tha) in proximity. (C) Almost lateral view of crowned areole cluster showing crowned areoles (cra), circumcluster areoles (cca), tubercle areole (tar) and thorn areole (thar). (D) Large cluster of crowned areoles, probably created by two very close clusters with a pair of crowned areoles in each cluster. (E) Overview of the anterior end. (F) Altered cuticular structure present at the anterior end. A and B from posterior region, C and D from anterior region of the worm.