2007-05-25 08:11:18 · 3 answers · asked by Hannah C 1 in Science & Mathematics ➔ Zoology
They copulate in the early morning. Two worms come in head to tail fashion in such a way that the spermathecal opening of one faces the male genital apertures. Each worm transfers the sperms to the spermathecae of the other member. Copulation involves mutual exchange of sperms.
2007-05-27 02:01:10 · answer #1 · answered by Ishan26 7 · 0⤊ 0⤋
Earthworms are monoecious (both female and male organs within the same individual). They have testes, seminal vesicles and male pores which produce, store and release the sperm, and ovaries and ovipores. However, most also have one or more pairs of spermathecae (depending on the species) that are internal sacs which receive and store sperm from the other worm in copulation. Some species use external spermatophores for transfer instead. Copulation and reproduction are separate processes in earthworms. The mating pair overlap front ends ventrally and each exchanges sperm with the other. The cocoon, or egg case, is secreted by the clitellum, the external glandular band which is near the front of the worm, but behind the spermathecae. Some indefinite time after copulation, long after the worms have separated, the clitellum secretes the cocoon which forms a ring around the worm. The worm then backs out of the ring, and as it does so, injects its own eggs and the other worm's sperm into it. As the worm slips out, the ends of the cocoon seal to form a vaguely lemon-shaped incubator (cocoon) in which the embryonic worms develop. They emerge as small, but fully formed earthworms, except for lacking the sexual structures, which develop later. Some earthworm species are mostly parthenogenetic.
2007-05-25 08:18:20 · answer #2 · answered by irish dave 2 · 0⤊ 0⤋
they have it how stupid are you?
2007-05-25 08:23:22 · answer #3 · answered by Anonymous · 0⤊ 0⤋