Prognathorhynchus, Meixner, 1929

Faubel, A. & Warwick, R. M., 2005, The marine flora and fauna of the Isles of Scilly: Free-living Plathelminthes (‘ Turbellaria’), Journal of Natural History 39 (1), pp. 1-45 : 30-31

Prognathorhynchus sp.

( Figure 7 )

Material examined

Site 1: one specimen in squash preparation stored on CD-ROM: 2003.6.6.3.

Description

Juvenile specimen with body length of 1.0 mm; without eyes; proboscis with a pair of hook organs on a basal muscular plate, oval to roundish (diameter of the oval side 43 M m). Each hook organ consists of three pointed spines the bases of which are rounded and swollen ( Figure 7 ). The median spine of the hook organ 35 M m long, the inner spine 15 M m long and the outer one 16.5 M m long. Distance between both hook organs 118 M m (distance measured between bases of median spines).

Discussion

To date the genus Prognathorhynchus comprises 13 species. Of these species two are nomina nuda, P. bacescui Mack-Fira, 1973 and P. sp. Ax and Armonies, 1987. Because of sexual immaturity information on the genital apparatus could not be presented. Based on the outline of the hook organs Prognathorhynchus sp. resembles with Prognathorhynchus dubius Meixner, 1929 (according to Evdonin 1977: 193, Figure 88v).

Figures

Figure 7. Prognathorhynchus sp. Hook organs of the proboscis on basal muscular plates. Scale bar: 50 Mm.