''Hrabea ogumai'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

oligochaete Oligochaeta () is a subclass of soft-bodied 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 megadril ...

worm Worms are many different distantly related bilateria, bilateral animals that typically have a long cylindrical tube-like body, no limb (anatomy), limbs, and usually no eyes. Worms vary in size from microscopic to over in length for marine ...

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

Sapporo is a Cities designated by government ordinance of Japan, designated city in Hokkaido, Japan. Located in the southwest of Hokkaido, it lies within the alluvial fan of the Toyohira River, a tributary of the Ishikari River. Sapporo is the capital ...

. 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 ''Stylodrilus'' is a genus of annelids belonging to the family Lumbruculidae. The genus has cosmopolitan distribution. Species There are 42 currently accepted species: * ''Stylodrilus absoloni'' (Hrabĕ, 1970) * ''Stylodrilus aclotudi'' Kaygor ...

'' subgenus ''Bythonomus'', but lacks the transversal vessels of the middle and posterior parts of the body, has one

testis A testicle or testis ( testes) is the gonad in all male bilaterians, including humans, and is Homology (biology), homologous to the ovary in females. Its primary functions are the production of sperm and the secretion of Androgen, androgens, p ...

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 (: vasa deferentia), ductus deferens (: ductūs deferentes), or sperm duct is part of the male reproductive system of many vertebrates. In mammals, spermatozoa are produced in the seminiferous tubules and flow into the epididyma ...

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

References

Lumbriculidae Monotypic annelid genera {{Annelid-stub