Chordodes moraisi ( Carvalho, 1942 )

Villalobos, C. De & Zanca, F., 2005, Ultrastructural redescription of Chordodes moraisi (Carvalho, 1942) and Chordodes straviarskii Carvalho and Feio, 1950, and re-interpretation of Chordodes gestri Camerano, 1904 and Pseudochordodes griffinii (Camerano, 1898) (Gordiida, Nematomorpha), Journal of Natural History 39 (8), pp. 597-606 : 598-600

Chordodes moraisi ( Carvalho, 1942)

( Figure 1 )

Neochordodes moraisi Carvalho 1942, p 219 .

Chordodes moraisi: Carvalho 1944, p 488 .

Holotype: one female, Viçosa Minas Gerais, Brazil (deposited in the Museu Nacional of Rio de Janeiro, Brazil).

Additional specimen. One male, Viçosa, Minas Gerais, Brazil. (This specimen is not in the collection of the Museu Nacional do Rio de Janeiro as indicated by Carvalho 1944. Unfortunately, it seems to be lost.)

Material examined. Holotype: SEM of posterior end and midbody.

Host. Blatta orientalis Linnaeus, 1758 and Miniblatta sp.

Description

Body length 208 mm, diameter in the middle region 2 mm. Anterior end tapered, without dark ring. Mouth terminal. Terminal end with 484 mm maximum width, with a slightly pronounced furrow in the ventral surface ( Figure 1A ). The cloacal opening is situated terminally at the posterior end and is rounded. The cuticle surrounding the cloacal opening is free of areoles but with small bristles. The body colour is uniformly yellowish brown. Dorsal and ventral grooves are hardly visible.

The cuticle shows four types of areoles which are numbered consecutively for the purpose of description and orientation. Types 1, 2 and 3 are distributed all over the body surface while the fourth areolar type is found only in the longitudinal ventral groove. Type 1 areoles are the most abundant ( Figure 1B, C ), they are rounded (15–23 mm in diameter) with a smooth surface or a surface partially traversed by superficial furrows. Scattered among these areoles, there are small areoles (type 2, Figure 1B ) (6.5–8.9 mm), rounded and with a long (9.3 mm), thin (1.3 mm) and eccentrically situated tubercle (tubercle areole). Type 3 areoles are very similar to type 1 ( Figure 1B, D ) in shape and size (21 mm) but different in their short (6.6 mm) and wide (5.3 mm) tubercle with a lateral position (also tubercle areole) and they are scarce or rarely found. In the interareolar groove there are scattered tubercles (13 mm) with pointed ends ( Figure 1C ). Type 4 areoles, crowned areoles ( Figure 1D, E ), appear as single structures, they are short and sometimes difficult to distinguish, rounded (8.7 mm diameter) with long filiform projections arising from their centre (125 mm) covering the longitudinal ventral groove ( Figure 1D, E ).

Comments

Carvalho (1942), based on a female collected from a cockroach, Blatta orientalis , described a new species as Neochordodes moraisi with one type of areole. In 1944, Carvalho studied a male specimen collected from Miniblatta sp. and when comparing it with the female specimen of N. moraisi he noticed that both specimens possessed areoles with filiform projections (crowned areoles) which had not previously been observed in the female, and transferred them to the genus Chordodes . Carvalho (1944), when describing the cuticle of C. moraisi , considered that it displayed three areolar types distributed on the whole surface of the body. Our ultrastructural study allows us to increase the number of areolar types for C. moraisi to four, two of which correspond to tubercle areoles. Carvalho (1944) described crowned areoles as distributed in pairs between or on which filiform projections emerge, shorter in the male and longer in the female. We observed that in the female, crowned areoles never appear in pairs and are distributed only in the longitudinal ventral groove, the projections arising at the areolar apex and not between areoles.

Figures

Figure 1. SEM of female of Chordodes moraisi, holotype. (A) Ventral view of posterior end with cloacal opening; (B) midbody cuticle, areoles types 1–3; (C) tubercle in the interareolar furrow; (D, E) areoles type 4 with long filaments in the longitudinal ventral groove. Scale bars: 100 mm (A, E); 50 mm (B–D).