Chordodes mizoramensis sp. n.

Schmidt-Rhaesa, Andreas & Lalramliana,, 2011, Chordodes mizoramensis (Nematomorpha, Gordiida), a new species of horsehair worm from Mizoram, North-East India, ZooKeys 75, pp. 1-8 : 2-6

Chordodes mizoramensis sp. n. Figs 13

Type locality.

Mamit Village, Mamit District, Mizoram, India, 23°54'54.94"N, 92°29'16.75"E. Collected July 21, 2010 by Lalramliana and Remsangpuia.

Holotype.

Male specimen from the type locality emerged from Hierodula sp. (type-host). Deposited in the Zoological Museum in the Department of Zoology at Pachhunga University College, Aizawl-Mizoram, India, accession number PUCZM - A/V/1114.

Paratype.

Male specimen from the same host specimen and same locality as the holotype. Deposited in the Zoological Museum in the Department of Zoology at Pachhunga University College, Aizawl-Mizoram, India, accession number PUCZM - A/V/1115.

Host.

Both specimens emerged from one specimen of Hierodula sp. ( Mantodea ) (Fig. 1A).

Etymology.

The name refers to the region in which the new species was found, Mizoram in NE India.

Description.

The holotype is 200 mm long, with a diameter of 1.3 mm in the mid-body region. Towards the posterior end, the diameter decreases to about 0.7 mm at the level of the cloacal opening. The anterior end is also tapered. The paratype is 265 mm long and has a diameter in the mid-body region of 1.5 mm;, at the level of the cloacal opening the diameter is 0.79 mm. The frontal tip in both specimens is white, whereas the remaining body is medium brown. A pattern of darker patches (the "leopard pattern") is present in both specimens; in the holotype this is more pronounced than in the paratype.

The cuticle contains six types of areoles (areoles are elevated cuticular structures), for which the terminology of Schmidt-Rhaesa et al. (2008) will be applied. Most abun dant are simple and bulging areoles (Fig. 1 B–D). Simple areoles are quite flat semicircular elevations with a rough surface but no further structure (Fig. 1D). Bulging areoles are more elevated and carry a small tuft of very short bristles on top (Fig. 1C, D). Compared with other species, bulging areoles are quite abundant; they are distributed among simple areoles alone or in groups, without forming clear patterns (Fig. 1C). Tubercle areoles regularly occur among the simple and bulging areoles (Fig. 1C, D), as rarely do thorn areoles (Fig. 1C). Tubercle areoles carry a finger-like process on top; thorn areoles have a strong thorn on top of a broader basis.

Characteristic for species of Chordodes are crowned areoles, which carry a crown of apical filaments on an elevated “stem”. Crowned areoles occur in pairs and are surrounded by so-called circumcluster areoles (Fig. 2A, B). This last type resembles the bulging areoles, but is longer (as elevated as the crowned areoles) and more slender (Fig. 2A, B). It also carries an apical tuft of short bristles, some of which can be slightly branched. Several circumcluster areoles have a more or less central “plug” among the apical bristles (Fig. 2 A–D). This “plug” is variable in shape, in some cases appearing as a drop-like structure emerging from the centre of the areole, but in others it is a broader, more voluminous structure. One pair of crowned areoles occurs in the centre, between the circumcluster areoles. Each crowned areole has a flat, smooth surface, with filaments emerging from the margin, except for the region where both areoles face each other (Fig. 2 A–C). The filaments spread flat from the central surface and project between the circumcluster areoles. Their length is about 25 µm. Most filaments divide several times, forming multiple branches (Fig. 2 A–D). Only one type of crowned areoles could be found.

The posterior end of the males is rounded, and a small median incision may be present (Fig. 3A, B). An approximately 150 µm broad ventral strip is free of areoles of the types described above, but forms polygonal or interdigitating compartments with a smooth surface (Fig. 3A, B). This smooth region extends around the ventral cloacal opening, which is about 200 µm anterior of the posterior margin of the worm. The cloacal opening is oval, with a number of long, fine bristles, the circumcloacal bristles, present in a ring emerging approximately 10 µm below its surface (Fig. 3C, D). In the region around the cloacal opening are further bristles; these are abundant and variable in length (Fig. 3C, D). The areoles described above are replaced at the posterior end, at least on the lateral sides, by elevated, conical areoles with an apical tuft of bristles (Fig. 3F). These areoles may represent bulging areoles, but are distinctly pointed apically and more abundant. In a region anterolateral to the cloacal opening is, in the region with areoles, an oval region with more bristles (Fig. 3A, B, E). These are very dense, appear to be all unbranched and have a lengths of up to about 30 µm.