Q.What are the spermathecae of Pheretima?

[!TLDR] Spermathecae in Pheretima are sac-like structures that store a mating partner's sperm. …

[!ANSWER] Spermathecae are the sperm-storage organs of Pheretima, essential to its reproduction despite being hermaphroditic.

Although each Pheretima individual bears both male and female reproductive organs, the earthworm still practises cross-fertilisation between two mating individuals rather than self-fertilisation. During copulation, each partner deposits sperm into the other's spermathecae — small, sac-like receptacles located in a set number of anterior body segments. This sperm is stored in the spermathecae until later, when the worm forms a cocoon and its own eggs are released; at that point, the stored sperm from the partner is used to fertilise the eggs. The spermathecae themselves do not produce gametes — their role is purely to receive and sto …

• Assuming the spermathecae produce sperm themselves — they only store sperm received from a partner. …