Tubifex are raised commercially, mainly for fish food: the reddish Tubifex tubifex. Soon, the Tubifex worm withdraws its body from the egg case by its backward wriggling movements. The cocoon is formed around the clitellum as a soft, box-like structure into which the ova and the sperm are deposited. At this stage, the sperm of one worm is passed into the spermathecae of the other worm.Īfter copulation, they separate and begin to produce egg cases containing eggs, called cocoons.
The penial setae of one worm penetrate into the tissues of other worm and thus the conjugants are held together. Thus, the spermathecal opening of each worm is nearer to the male apertures of another worm. Two mature Tubifex worms undergo copulation by joining ventral and anterior surfaces together with their anterior ends pointing opposite directions.
Copulation and cocoon formation Īlthough 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. In mature specimens, the reproductive organs are clearly found on the ventral side of the body. These minute reproductive organs are attached to the ventral side of the body wall in the celomic cavity. Tubifex worms are hermaphroditic: each individual has both male (testes) and female (ovaries) organs in the same animal. 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. Tubifex is a cosmopolitan genus of tubificid annelids that inhabits the sediments of lakes, rivers and occasionally sewer lines.
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