Melomystrongylus sepikensis, Smales, 2009

Durette-Desset, Marie-Claude & Digiani, María Celina, 2023, Revision of the genera of Heligmonellidae (Nematoda, Heligmosomoidea), parasitic in Muridae from New Guinea, Parasite (Paris, France) 30 (63), pp. 1-34 : 5-6

3.1.1.1 Melomystrongylus sepikensis ( Figs. 1A–1D )

3.1.1.1.1 Synlophe (number of worms studied not provided). Sections analyzed herein are those within proximal part of body: male (Fig. 16/1A) and female (Fig. 17/1B), and at midbody: male (Fig. 19/1C) and female (Fig. 20/1D). In all sections, lateral cords illustrated; ridges numbered in Figure 16/1A.

Within proximal body: in both sexes, careen absent, synlophe with hypertrophied ventral ridge (ridge 5’, interpreted herein as comarete) and two large right ridges associated to right lateral cord; axis of orientation described as oblique by Smales [ 30].

Figure 1A (male section): nine ridges irregularly spaced with three gaps (arrowheads) of which largest situated on right-ventral quadrant; tips of ridges 1 and 1’ divergent (curved arrows).

Figure 1B (female section): 12 ridges less irregularly spaced; gaps much smaller than those in male section (arrowheads).

At midbody: Figures 1C and 1D , synlophe very different from that within proximal body; ridges increased in number (14–16), small and subequal in size, lacking clear orientation. All features characterizing synlophe at proximal part disappear.

Figure 1C (male section): all ridges subequal with no systematic orientation, most oriented perpendicularly to body surface; small ridge-free space present on right-ventral quadrant (arrowhead).

Figure 1D (female section): right ventral ridges largest; two pairs of ridges with divergent tips present (curved arrows): one right-dorsal and one right-ventral; no ridges with convergent tips observable, remaining ridges mostly perpendicular to body surface.

3.1.1.1.2 Bursa (illustrated in [ 30]: Figs. 22 and 25). Figure 22: dorsal ray and rays 8, orientation not specified. Figure 25: left lobe, left ray 8 and left branch of dorsal ray, lateral view.

From the written description [ 30]: bursa dissymmetrical with left lobe larger; left rays 2 and 3 longer than rays 4-6.

Figures

Figure 1. Genus Melomystrongylus Smales, 2009. Body sections. A–D Melomystrongylus sepikensis Smales, 2009. A, B within proximal body. A male, B female; C, D at midbody. C male, D, female. E–H Melomystrongylus somoroensis Smales & Heinrich, 2010. E, F within proximal body. E male, F female. G, G’ at midbody, male. H female “at posterior end of midbody” (sic). Sources: A–D redrawn from [30]. E–H redrawn from [45]. G’ modified figure, reversed on its frontal axis with respect to the original.