Pomphorhynchus laevis

Reier, Susanne, Sattmann, Helmut, Schwaha, Thomas, Harl, Josef, Konecny, Robert & Haring, Elisabeth, 2019, An integrative taxonomic approach to reveal the status of the genus Pomphorhynchus Monticelli, 1905 (Acanthocephala: Pomphorhynchidae) in Austria, International Journal for Parasitology: Parasites and Wildlife 8, pp. 145-155 : 148

3.1.1. Pomphorhynchus laevis

Juvenile specimens obtained from Alburnoides bipunctatus (Bloch, 1782) of the river Sulm (Styria) were identified as P. laevis . Four specimens were examined under the light microscope since the hooks exhibited no autofluorescence in the confocal scans. They had a cylindrical proboscis with twelve hooks per row. The 3- D reconstruction of one specimen emphasized the assignment to the species P. laevis since no extensions on the basal hooks of the proboscis were visible as it was described by Meyer (1933) and Špakulová et al. (2011) ( Fig. 2 C, F ). The anterior and basal hooks exhibit long hook roots ( Fig. 2 C ). The furcation of the basal roots described by Meyer (1933) could not be confirmed in the 3- D reconstruction since the thicker outer parts are interconnected by a very thin matrix. Also, the basal circle of hooks is located on the posterior part of the proboscis as it is known for P. laevis ( Meyer, 1933; Špakulová et al., 2011; Hohenadler et al., 2017). Overall, 17 longitudinal rows of hooks were counted.

Figures

Fig. 2. Proboscis and longitudinal row of hook roots of the three determined Pomphorhynchus species. All images are volume rendering of the 3-D stacks. In volume rendering each grayscale value is assigned a color according to an arbitrary colormap. The depiction depends on which values and how transparent they are displayed. In the present images a glow color map is used, which assigns graded colors from black (background) to shades of red-orange-yellow. A. Volume rendering of a confocal laser scan image stack of the proboscis of P. tereticollis. B. Volume rendering of the sectioned proboscis of P. bosniacus including reconstructed hooks as surface rendering. C. Volume rendering of the sectioned proboscis of P. laevis including reconstructed hooks as surface rendering. D-F. Internal view of the sectioned proboscids including a single longitudinal row of hooks. D. P. tereticollis. E. P. bosniacus. F. P. laevis. Legend: Red arrow = last circle of hooks; green arrow = extensions on basal hook roots of P. tereticollis; blue arrow = basal hooks attached in the middle of hook roots of P. bosniacus; yellow arrow: lack of extensions on basal hook roots of P. laevis. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)