Stylodrilus sp. 1

MATERIAL EXAMINED. — Station 2: 1 sexually mature, unmated specimen, slide 11.007.03 (first 14 segments) and vial AB31525649 (posterior part in 96% ethanol), IRScNB, I.G. 32392.

REMARKS

This is a Stylodrilus species with simple-pointed setae. Spermathecal and male pores are in IX and X, respectively. Only one spermathecal ampulla is visible, on left side of the specimen; ampulla, small, spherical, without sperm, probably partially-developed. Atria are small, pear-shaped, immediately ending with small penis.Vasa deferentia join atria sub-apically. Posterior blood vessels not visible. No current diagnosis of Stylodrilus species fits this description. This is most probably a new species, but it seems preferable to have additional material before formalizing a taxonomic decision. At best, Stylodrilus sulci (Hrabě, 1934) seems to be the closest relative, but that groundwater species has long, oval atrial ampullae, narrowing into a duct, without a penis. Stylodrilus lemani has atria immediately ending with a penis, but its atria are tubular, and posterior dorsolateral blind blood vessels are present, with numerous long, irregular appendages.