Tubifex

Genus of annelid worms Tubifex Scientific classification Kingdom: Animalia Phylum: Annelida Clade: Pleistoannelida Clade: Sedentaria Class: Clitellata Order: Tubificida Family: Naididae Subfamily: Tubificinae Genus: TubifexLamarck, 1816 Type species Lumbricus tubifexMüller, 1774 Tubifex is a widespread genus of tubificid segmented worms (annelids) that inhabits the sediments of lakes, rivers and occasionally sewer lines. They are globally distributed. At least 13 species of Tubifex have been identified, with the exact number not certain, as the species are not easily distinguishable from each other.[citation needed] Reproduction Tubifex worms are hermaphroditic: each individual has both male (testes) and female (ovaries) organs in the same animal. These minute reproductive organs are attached to the ventral side of the body wall in the celomic cavity. In mature specimens, the reproductive organs are clearly found on the ventral side of the body. [citation needed] Copulation and cocoon formation Although the Tubifex worms are hermaphrodites, the male and female organs become mature at different times; thus self-fertilization is avoided, and cross-fertilization is encouraged. Two ma