Trichodrilus sp. 1

MATERIAL EXAMINED. — One sexually mature, unmated specimen, IRScNB, I.G. 32392, slide 11.251.03b (first 14 segments); station 14 (Appendix).

REMARKS

This specimen can be characterized by tubular to quadrangular atria, 78 µm long, 57 µm wide (length/width = 1.4), with thin muscular layer (2.3-4.0 µm thick), short proximal ducts, 12 µm long, with small, conical, external penes, 8.8 µm long. Atria are covered by discrete groups of prostate cells. There are two pairs of spermathecae in XI and XII with large, ovoid ampullae and short (15 µm) ducts. Posterior blood vessels cannot be studied on this anterior fragment.

Among Trichodrilus species with tubular atria and two pairs of spermathecae, T. leruthi Hrabě, 1939, T. intermedius (Fauvel, 1903) and T. tacensis Hrabě, 1963 are probably the closest species to this specimen; however, atria of those species are slender (length/width = 2.4) and larger, and they do not have atrial ducts. Trichodrilus sp. 1 is probably a new species. Unfortunately, the scarcity of material and its suboptimal state of conservation prevent us from describing this taxon into more detail, or to formalize a taxonomic decision.