Getting Down and Dirty with Lumbricus terrestris


As far as reproduction goes for the species, Lumbricus terrestris, there is more than one method for reproduction. Most earthworms, including this species, are hermaphrodites who use cross fertilization as means to sexually reproduce. However, other times there has been reported self-fertilization also seen in earthworms (Karaca 2011).

What does it mean to be a cross fertilizing hermaphrodite? According to J. Díaz Cosín et al., in the book Biology of Earthworms, 2011, this means the worm is using reciprocal insemination, which means giving and recieving spermm in the same mating period. This also means that the species has both male and female parts. How does the species L. terrestris keep its reproductive organs separate? The answer can be found back in the section Form and Function. In essence the worm is segmented and keeps these parts in different segments. The book Biology of Earthworms by J. Díaz Cosín 2011, explains the different reproductive organs found in the earthworm. The female internal organs , are  considered to be the ovaries, oviducts, female pores, and spermathecae and the male internal reproductive organs,  are the testes and male funnels, seminal vesicles, deferent ducts.The male parts also include the male pores, which are slightly less developed then the female pores. The foremetioned parts were all internal but there are also external organs involved in the reproduction process. These include, the clitellum, tubercula pubertatis, and sexual papillae There are also tubercula and quetae included in the reproductive system of Lumbricus terrestris. Now that a majority of the reproductive organs were listed, this website will dive in into what each part does. (Karaca 2011).

First an image is shown to place the reproductive system in persepective. 

Figure 1:This above figure shows a few of the sexual organs mentioned in the above paragraph. This numbers match up with segment number given in the book Biology of earth Worms by J. Díaz Cosín.

 The first parts discussed, will be the tubercula and quetae. These external organs attach and secure different members of Lumbricus terrestris during the process of cross-fertilization (Karaca 2011).

Now some of the internal reproductive organs will be explained in detail. First the, clitellum. This organ in the Lumbricidae family is according to Cosín, though to move “backwards and seminal groves are developed from the male pores to the tubercula pubertatis. Spermatozoa flow through the seminal groves to get into the partner’s spermathecae pores”. So, it acts as a sperm transfer tube in between to hermaphrodite partners. Much of the Lumbricade family also contains spermatophores, which are small clear capsules filled with Spermatozoa. They are attached to the body wall of the earthworm. Their function isn't exactly known, but it suggested they probably are also used in the transfer of sperm, and that they fertilize ova. (Karaca 2011).
Figure 7. Earth worm cacoons Retrieved from by signing up for and downloading at Kuhn Photos. 2013/12/08
Earthworms are hermaphroditic because it is less costly and beneficial to the species than self-fertilization, when the density of earthworms on a geographical area is high. According to Cosín 2011, The hermaphrodites, due to limited resources,must trade-off between male and female reproductive functions . Also, there are benefits and disadvantages to being either. Earthworms produce their offspring in a cocoon, which can release one or more offspring each. In general L. terrestris produces their cocoons in their burrows , so the cocoons can be safe.

 In conclusion, the L. terrestris has options for reproduction, yet in most cases cross-fertilization is the most beneficial to the species in an area of high concentration of earthworms. Earthworms have many sexual organs, both external and internal, that they organize in their segments. Each organ has a specified purpose.
Earthworms have shown many activities in selecting their mate, such as inspecting their neighbors burrow, skin piercing, control of produxtion of sperm, and even more. To find out more you could read the book Biology of Earthworms edited by Ayten Karaca, 2011.


Earthworms interact with many different organisms in many different ways. To find out more, go to our Interactions page!

Check out where we gathered our information from on our Reference page