Rogneda polyrhabdota, AX, 1959

Artois, Tom J., 2008, Revision of Rogneda Uljanin, 1870 (Rhabditophora, Eukalyptorhynchia, Polycystididae) with the description of seven new species, Zoological Journal of the Linnean Society 153 (1), pp. 1-28 : 6

THE POLYRHABDOTA -GROUP

The polyrhabdota -group consists of two species with a reticulate dorsal pigmentation: R. polyrhabdota ( Fig. 6A ) and R. schaereri ( Figs 1A , 6B , 7D, E ). They have a stylet B resembling that of the steueri-group (see further below). This stylet is almost twice as long in R. schaereri as in R. polyrhabdota . The proximal part of plate B2 is sturdier in R. polyrhabdota . Moreover, plate B2 is relatively smaller in R. polyrhabdota (± 40% of plate B1; ±50% in R. schaereri ). Stylet A in both R. polyrhabdota and R. schaereri consists of one plate only, which at first sight suggests a close relationship between the two species. However, in R. polyrhabdota it is clearly a plate A1, with the distal part serrated and a thickened area at about its midpoint, at the place where in other species plate A2 is attached. This is much less obvious in R. schaereri . Here stylet A is a simple plate, with a stronger proximal end, more resembling plate A2 of the species of the steueri- group. Therefore, the resemblance between the two species could as well be superficial and not represent a common descent.

Figures

Figure 1. A, pigmentation pattern as seen on a whole mount (R. schaereri sp. nov.). B, habitus of live animal (R. colpaerti sp. nov.). C, schematic representation of a stylet. D, schematic reconstruction on sagittal sections of the genital system from the left hand side (R. hibernica). Abbreviations: 1, plate 1; 2, plate 2; cga, common genital atrium; de, ejaculatory duct; e, eye; fd1, female duct type I; gl, glands; gp, gonopore; m, mouth; ma, male atrium; mb, male bursa; mu, muscles; od, oviduct; ov, ovary; p, proboscis; ph, pharynx; pv3, prostate vesicle type 3; stA, stylet A; stB, stylet B; t, testis; ut, uterus; vd, vitelloduct; vde, vas deferens; vi, vitellarium; vs, seminal vesicle.

Figure 6. Stylets of the representatives of the polyrhabdota-group. A, R. polyrhabdota (from a specimen from Greece). B, R. schaereri sp. nov. (from the holotype). Stylet A is indicated by an A, stylet B by a B. Plates B1 and B2 are indicated by a 1 and a 2, respectively. Scale bar = 25 Mm.

Figure 7. Stylets of the representatives of the hibernica-group and the habitus and stylet of R. schaereri sp. nov. A, R. hibernica (from the neotype). B, R. vangronsveldi sp. nov. (from the holotype). C, R. licyae sp. nov. (from the holotype). D, E, R. schaereri sp. nov. [D, habitus; E, stylets (both from the holotype)]. Scale bars = A–C, E = 20 Mm; D = 100 Mm.