''Hrabea ogumai'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

oligochaete Oligochaeta () is a subclass of animals in the phylum Annelida, which is made up of many types of aquatic and terrestrial worms, including all of the various earthworms. Specifically, oligochaetes comprise the terrestrial megadrile earthworms ...

worm Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always). Worms vary in size from microscopic to over in length for marine polychaete wor ...

originally described by Yamaguchi in 1936 from specimens collected from subterranean waters in

Sapporo ( ain, サッ・ポロ・ペッ, Satporopet, lit=Dry, Great River) is a city in Japan. It is the largest city north of Tokyo and the largest city on Hokkaido, the northernmost main island of the country. It ranks as the fifth most populous city ...

. The genus is named after the great oligochaete specialist Dr. Sergej Hrabe, and the species after Prof. K. Oguma. The body of ''Hrabea'' is long, and consists of 146–183 segments. The body wall is thin and transparent, but when illuminated, shows a light green tint. It swims actively by lateral undulating movements. The setae are one-pointed. ''Hrabea ogumai'' is similar to '' Stylodrilus'' subgenus ''Bythonomus'', but lacks the transversal vessels of the middle and posterior parts of the body, has one

testis A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testostero ...

and male funnel (in segment X) instead of two (in segments IX and X), and has a pear-shaped atrium, to which the

vas deferens The vas deferens or ductus deferens is part of the male reproductive system of many vertebrates. The ducts transport sperm from the epididymis to the ejaculatory ducts in anticipation of ejaculation. The vas deferens is a partially coiled tube ...

is connected at the apical end, rather than at the lower half.

References

Lumbriculidae Annelid genera Monotypic protostome genera {{Annelid-stub